Pre-trigger and post-trigger acquisition for a no dead time acquisition system, where the data being displayed does not include a related trigger event, has a variable record length buffer having a maximum record length equal to a maximum desired pre-trigger interval, and has a trigger FIFO and timer for delaying the related trigger event. The record length of the buffer is determined by the desired pre-trigger interval, and fast rasterizers access the oldest data that encompasses the desired pre-trigger data. A first trigger event in the trigger signal may be delayed by a desired post-trigger interval before the fast rasterizers begin drawing the waveform data that encompasses the desired post-trigger data.

The "dead time" of a measurement instrument, such as an oscilloscope, is a time period during which data acquisition circuitry does not respond to a valid trigger event because the oscilloscope is busy performing other tasks and so is not able to process trigger events that may occur. Consequently, a waveform representing an electrical signal being monitored is not displayed for the missed valid trigger event. In an analog oscilloscope, for example, dead time occurs during the beam retrace time on a cathode ray tube. In a digital oscilloscope, dead time often occurs when the instrument is busy reading data from an acquisition memory associated with a previous acquisition, or busy drawing the acquired processed data to produce an image of the waveform for display.
Circuits under test often operate at rates much faster than a standard digital oscilloscope can display the corresponding waveforms. In fact, the typical digital oscilloscope "ignores" most trigger events because it is busy processing and drawing waveforms relating to data acquired in response to a prior trigger event. It is an unfortunate fact that such electronic circuits under test occasionally work in an unexpected manner. Occurrences of incorrect operation of the circuits under test may be rare, perhaps occurring once in thousands of correct cycles of operation. Thus, the oscilloscope may not acquire data representing waveforms that exhibit the incorrect operation of the circuit under test (i.e., an anomaly), because the oscilloscope may be busy at the instant that the anomaly occurs. An oscilloscope user may have to wait a long time in order to view the incorrect operation. Since only a small fraction of the waveforms are drawn on the oscilloscope display, failure to observe the incorrect operation cannot give the user confidence that the circuit under test is operating properly.
The basic digital oscilloscope has an architecture in which data is received and stored in an acquisition memory, and then acquisition is halted by a trigger event after a defined post-trigger interval. The acquired data then is read from the acquisition memory for processing and waveform drawing on a display before the acquisition system is again enabled to respond to new trigger events.
U.S. Pat. No. 7,652,465, issued to Steven Sullivan et al on Jan. 26, 2010, entitled "No Dead Time Data Acquisition", herein incorporated by reference, is one attempt to enable the acquisition for display of data representing all trigger events. A measurement instrument receives a digitized signal representing an electrical signal being monitored and uses a fast digital trigger circuit to generate a trigger signal, wherein the trigger signal includes all trigger events within the digitized signal. The digitized signal is compressed as desired and delayed by a first-in, first-out (FIFO) buffer for a period of time (pre-trigger delay) to assure a predetermined amount of data prior to a first trigger event in the trigger signal. The delayed digitized signal from the FIFO is delivered to a fast rasterizer or drawing engine, upon the occurrence os the first trigger event, to generate a waveform image. The waveform image is then provided to a display buffer for combination with prior waveform images and/or other graphic inputs from other drawing engines. The contents of the display buffer are provided on a display screen at a display update rate to show a composite of all waveform images representing the electrical signal.
Two or more drawing engines may be used for each input channel of the measurement instrument to produce two or more waveform images, each waveform image having one of the trigger events at a specified trigger position within a display window. The waveform images are combined to form a composite waveform image containing all the trigger events for combination with the previous waveform images in the display buffer or with graphics from other drawing engines. For certain trigger positions within the display window, an indicator is provided to show that a trigger event may have been missed. Also, when there are no trigger events, a graphic of the signal content may still be provided for the display.
The described "no dead time acquisition system" has limited usefulness in some ways. For example, when zoom is turned on, a zoom window may be moved to a pre-trigger location that does not include a trigger event within the zoom window, i.e., the desired data for display occurs appreciably before the trigger event, and thus is not in the FIFO when the trigger event occurs to initiate waveform drawing by the fast rasterizers. In such a case, there may be no data for inclusion within the zoom window for display because the data in the FIFO has already been overwritten. This is because the no dead time acquisition system acquires and processes for display only the digitized signal from the FIFO which occurred around the trigger event.
Similarly, the zoom window may be moved to a post-trigger location that also does not include a trigger event within the zoom window. That is, the drawn waveform including the trigger event is completed before the desired post-trigger location occurs in the input signal, or the horizontal position for the waveform image may be delayed such that the acquisition is delayed from the trigger point. In these latter two cases, the no dead time acquisition system may not have data to produce a waveform for display since the waveform display is generated from the FIFO in response to the trigger event and is limited to the display screen size.
An example of the pre-trigger problem is shown in display 100 FIG. 1. In the upper portion of prior art FIG. 1, a waveform 110 is shown that represents a long record length acquired data signal. In waveform 110, a trigger point is indicated by a dot and a zoom window location is enclosed by brackets. The contents of the zoom window are shown in waveform 120 in a lower portion of the display 100. With an ordinary long record length acquisition system as shown, this behavior is not a problem as the instrument looks into the waveform memory post-acquisition to extract the data points necessary to draw the contents shown in the zoom window. However, since one of the basic tradeoffs to make the no dead time acquisition system work with current technology is that the data acquired during each acquisition cycle is highly compressed, this limits the amount of data that needs to be processed in real time by the specialized drawing hardware of the no dead time acquisition system. If this extremely short record defined by the FIFO were used directly to draw the zoom window using only the data within the FIFO, the results would be very unsatisfying. For example for a record length of 450 pairs of points, if the display is zoomed by a factor of 10,000, which is not unusual for a modern long record length instrument, there would be far less than one pair of data points available within the zoom window. Clearly, no meaningful information is drawn in this case, so the no dead time acquisition system cannot produce the display.
The pre-trigger zoom record cannot be acquired at full resolution in the no dead time acquisition system because there is no way to know when to stop a particular acquisition cycle, i.e., the acquisition system cannot know to stop acquiring before the trigger event becomes visible. In other words the pre-trigger period for the no dead time acquisition system is defined by the length of the FIFO.
When the zoom window is moved to a post-trigger location, as shown in FIG. 2, the traditional long record length acquisition system simply counts off a longer delay period after the trigger before stopping. However, this simple method is not possible with the no dead time acquisition system. The arrows of FIG. 2 mark individual trigger events in the input signal. When the first trigger event occurs, the data associated with that trigger is not available until the time indicated by brackets near the right edge of the screen. The acquisition system delays processing this data until the proper time, but during this delay five more trigger events are detected. Then during the processing of the delayed data another two trigger events are detected. Each of these seven trigger events have corresponding data that need to be identified and processed if the acquisition is to maintain its "no dead time" status.

Pre-trigger and post-trigger acquisition for no dead time acquisition system


A method for allocating a channel quality information channel (CQICH) in a communication system is disclosed. After fast switching from a serving anchor base station (BS) to a target anchor BS, a mobile station (MS) detects absence of a CQICH allocated from the target anchor BS. Upon detecting the absence of the allocated CQICH, the MS sends a request for allocating the CQICH to the target anchor BS. Upon receiving the CQICH allocation request, the target anchor BS detects a need to allocate a CQICH to the MS.

1. Field of the Invention
The present invention relates generally to a system and method for allocating a Channel Quality Information Channel (CQICH) in a communication system.
2. Description of the Related Art
Active research on the next generation communication system is being conducted to provide users with desired services which can meet a desired Quality-of-Service (QoS) at a high data rate.
A wireless Local Area Network (LAN) communication system and a wireless Metropolitan Area Network (MAN) communication system support a high data rate. The wireless MAN communication system, one of the typical Broadband Wireless Access (BWA) communication systems, has broader service coverage and supports a higher data rate, compared with the wireless LAN communication system. Therefore, active research on the next generation communication system is being conducted to develop a new communication system that guarantees mobility of a mobile station (MS) and QoS to the wireless LAN communication system and the wireless MAN communication system, both of which guarantee a higher data rate, to thereby support a higher data rate of the next generation communication system.
A system employing an Orthogonal Frequency Division Multiplexing (OFDM) scheme and/or an Orthogonal Frequency Division Multiple Access (OFDMA) scheme to support a broadband transmission network for physical channels of the wireless MAN communication system is known as an Institute of Electrical and Electronics Engineers (IEEE) 802.16 communication system. The IEEE 802.16 communication system, applies the OFDM/OFDMA scheme to the wireless MAN communication system, and can therefore support high-speed data transmission by transmitting physical channel signals using a plurality of subcarriers. For convenience, the following description will be made with reference to the IEEE 802.16 communication system, one of the typical BWA communication systems.
A description will now be made of a Fast Base Station Switching (FBSS) scheme among various handover schemes for connection switching from a serving base station (BS) to a target BS in the IEEE 802.16 communication system.
The FBSS scheme is a handover scheme that uses selection diversity and fast switching mechanism to improve link quality. In the FBSS scheme, a mobile station (MS) exchanges signals with only one active BS, i.e., an anchor BS, among active BSs included in the MS's diversity set. The anchor BS is a type of serving BS, and is replaceable (or switchable) according to a BS selection scheme of the MS. A description will now be made of the diversity set.
Each of active BSs constituting the MS's diversity set is distinguished with a temporary BS indicator (Temp BS ID), and all of the active BSs constituting the diversity set share capability, security parameters, service parameters, and full Medium Access Control (MAC) context information of the corresponding MS. Each of the active BSs constituting the diversity set can be excluded from the diversity set or a new BS currently not included in the diversity set can be added to the diversity set as a new active BS according to strength of a signal received (by the MS) from each active BS.
The MS selects one of the active BSs constituting the diversity set as an anchor BS. In this case, strength, for example, carrier-to-interference and noise ratio (CINR), of a signal received from the active BS selected as the anchor BS is highest, compared with CINRs of signals transmitted by the other active BSs constituting the diversity set. Therefore, in the FBSS scheme, the MS "performs communication" with only the anchor BS. The anchor BS that currently communicates with the MS will be referred to as a "serving anchor BS." The MS measures signal quality for each of the active BSs constituting the diversity set while communicating with the serving anchor BS. Measuring the signal quality means measuring a CINR of the corresponding signal. Upon detecting the presence of any active BS providing higher signal quality than that of the current serving anchor BS as a result of the signal quality measurement, the MS determines to handover from the serving anchor BS to the active BS that provides the higher signal quality than that of the current serving anchor BS, accomplishing fast switching. Herein, an active BS, to which the MS performs fast switching, that provides a higher signal quality than that of the current serving anchor BS will be referred to as a "target anchor BS."
With reference to FIG. 1, a description of an FBSS-based fast switching operation of an MS in a conventional IEEE 802.16 communication system will now be given. FIG. 1 is a flowchart illustrating an FBSS-based fast switching operation of an MS in a conventional IEEE 802.16 communication system.
Referring to FIG. 1, an MS performs communication with a serving anchor BS in step 101. Thereafter, the MS measures signal quality for each active BSs constituting the MS's diversity set in step 103. Herein, the phrase an MS performs communication with a serving anchor BS means that allocation information for the MS is included in MAP messages, i.e., a downlink MAP (DL-MAP) message and an uplink MAP (UL-MAP) message, transmitted by the serving anchor BS.
The MS determines in step 105 whether it should switch the serving anchor BS, i.e., it should perform a fast switching operation. Herein, the MS determines to switch the serving anchor BS if there is any active BS having a higher signal quality than that of the serving anchor BS. If there is no need to switch the anchor BS as a result of the determination, the MS returns to step 101. However, if it is determined in step 105 that there is a need to switch the anchor BS, the MS proceeds to step 107.
In step 107, the MS detects a start point of a switch period. Herein, the switch period refers to a period in which an MS reports a serving anchor BS that it will perform a fast switching operation to a new active BS, i.e., a target anchor BS, rather than the serving anchor BS. The switch period will be described later in detail with reference to FIG. 2. In step 109, after detecting the start point of the switch period, the MS transmits a Temp BS ID of a target anchor BS to which it will perform a fast switching operation from the serving anchor BS, to the serving anchor BS in the switch period. Herein, the MS transmits the Temp BS ID of the target anchor BS (i.e., a codeword corresponding to the Temp BS ID), to the serving anchor BS through a CQICH allocated from the serving anchor BS. The CQICH is a channel used by the MS to transmit a control signal in a process of feeding back a Channel quality information (CQI) value of the serving anchor BS or performing an FBSS-based fast switching operation.
Possible codewords mapped to corresponding Temp BS IDs are shown in Table 1 below.
TABLE 1ValueDescription0b100000Active BS for TEMP_BS_ID = 0000b100001Active BS for TEMP_BS_ID = 0010b100010Active BS for TEMP_BS_ID = 0100b100011Active BS for TEMP_BS_ID = 0110b100100Active BS for TEMP_BS_ID = 1000b100101Active BS for TEMP_BS_ID = 1010b100110Active BS for TEMP_BS_ID = 1100b100111Active BS for TEMP_BS_ID = 1110b101000Acknowledgement of Receipt of Anchor BS Switch IE
In Table 1, "Value" represents codewords mapped to corresponding Temp BS IDs of active BSs. For example, if the MS desires to perform fast switching from a serving anchor BS to a target anchor BS with Temp BS ID="011", the MS transmits a codeword "0b100011" mapped to the Temp BS ID='011' to the serving anchor BS through a CQICH. In Table 1, a codeword '0b101000' is not a codeword mapped to a Temp BS ID of an active BS, but is a codeword used by the serving anchor BS to inform the MS that it has received a transmitted anchor BS switch Information Element (Anchor BS Switch IE). A format of the Anchor BS Switch IE will be described later in detail.
In step 111, the MS transmits a CQI value for the serving anchor BS through a CQICH being identical to the CQICH used for transmitting a codeword mapped to the Temp BS ID of the target anchor BS. The MS determines in step 113 whether an Anchor BS Switch IE indicating a fast switching cancel request to the target anchor BS is received from the serving anchor BS. A format of the Anchor BS Switch IE is shown in Table 2.
TABLE 2SyntaxSizeNotesAnchor BS Switch IE( ){N_Anchor BS_Switch 4bitsNumber of Anchor BS switching indicated in this IEfor(i=0;i<N_AnchorBS_Switch;i++){CID16bitsBasic CID of a MS whose anchor BS switching isindicated in this IEAction code 2bits00—The MS shall switch to the Anchor BS specifiedin the fast Anchor BS selection information in theFast-feedback channel, at the default time specifiedby the switching period defined in the DCD01—The MS shall switch to the Anchor BS specifiedin this IE and at the action time specified in this IE10—The MS shall cancel all anchor switchingprocedure, stop switching timer and remain on thecurrent anchor BS11—reservedif (Action code ==01){Action time(A) 3bitsIn units of frames, 000 means the MS shall switch atthe default time specified by the switching perioddefined in DCDTEMP BS ID 3bitsTEMP BS ID of the anchor BS to switch to.}If(Action code==00 ∥Action code==01){CQICH Allocation 1bitTo indicate if CQICH allocation at the new AnchorIndicatorBS is included in this IEif(CQICH AllocationIndicator ==1){CQICH IDVariableIndex to uniquely identify the CQICH resourceassigned to the MS after the MS switched to the newAnchor BSFeedback channel 6bitsIndex to the Fast feedback channel region of the newoffsetAnchor BS marked by UIUC = 0Period(p) 2bitsA CQI feedback is transmitted on the CQICH every2p framesFrame offset 3bitsThe MS starts reporting at the frame of which thenumber has the same 3 LSB as the specified frameoffset. If the current frame is specified, the MSshould start reporting in 8 frames.Duration(d) 3bitsA CQI feedback is transmitted on the CQI channelsindexed by the CQICH ID for framesif d = 0, the CQICH is deallocatedif d = 111, the MS should report until the BScommend for the MS to stop}}}
In Table 2, N_Anchor BS_Switch represents the number of anchor BS fast switching informations included in the Anchor BS Switch IE, and the Anchor BS Switch IE can include anchor BS fast switching informations allocated to a plurality of MSs because it is included in a MAP message before being broadcasted. Herein, the number of anchor BS fast switching informations is equivalent to "N_Anchor BS_Switch", and each of "anchor BS fast switching informations" is equivalent to each of informations in "for (i=0; i<N_Anchor BS_Switch; i++)" structure. The Anchor BS Switch IE includes a Connection Identifier (CID) for each of the anchor BS fast switching informations, an Action code, and CQICH allocation information for the Action code. The CID represents a basic CID for each MS, and the Action code represents information on a switch period in which the MS fast-switches to the target anchor BS, or information used for commanding the MS to fast-switch to a target anchor BS indicated by the serving anchor BS in a period (i.e., a switch period), indicated by the serving anchor BS, or for commending the MS to cancel the fast switching.
As shown in Table 2, Action code="00" indicates that the MS should perform a fast switching operation to the target anchor BS at a default time in a switch period defined in a Downlink Channel Descriptor (DCD) message, Action code='01' indicates that the MS should perform a fast switching operation to the target anchor BS at an action time specified in the Anchor BS Switch IE, and Action code='10' indicates that the MS should cancel the fast switching operation and maintain communication with the serving anchor BS.
In Table 2, CQICH Allocation Indicator represents CQICH allocation information to be used by the MS in the target anchor BS. The CQICH allocation information includes CQICH ID, Feedback channel offset indicating a position of a CQICH actually allocated to the MS in a CQI field defined in a UL-MAP message, Period (p) indicating a period in which the MS reports a CQI value, Frame offset indicating a time at which the MS starts reporting a CQI value, and Duration (d) indicating information on effective duration of a CQICH allocated from the target anchor BS. Therefore, an MS, receiving the CQICH allocation information, reports a CQI value to the target anchor BS through the CQICH every 2p frame for frame duration after the Frame offset time.
If it is determined in step 113 that an Anchor BS Switch IE indicating a fast switching cancel request to the target anchor BS is received from the serving anchor BS (i.e., the Action code is set to "10"), the MS proceeds to step 115. In step 115, the MS cancels a fast switching operation (from the serving anchor BS to the target anchor BS), and then ends the process.
However, if it is determined in step 113 that an Anchor BS Switch IE indicating a fast switching cancel request to the target anchor BS is not received from the serving anchor BS, the MS proceeds to step 117 where it determines whether the switch period has expired. If it is determined that the switch period has not expired, the MS returns to step 109 where it can repeatedly transmit information indicating a desired fast switching operation to the target anchor BS (i.e., the MS transmits a codeword mapped to a Temp BS ID of the target anchor BS), to the serving anchor BS. The repeated transmission of the codeword mapped to the Temp BS ID of the target anchor BS continues until the switch period has expired in step 117 or the Anchor BS Switch IE indicating a fast switching cancel request to the target anchor BS is received from the serving anchor BS in step 113 even though the switch period has not expired.
If it is determined in step 117 that the switch period has expired, the MS proceeds to step 119 where it determines whether CQICH allocation information to be used in the target anchor BS has been received from the serving anchor BS. Herein, the MS can be aware of the CQICH allocation information to be used in the target anchor BS through CQICH allocation information previously allocated before the MS performs a fast switching operation from the serving anchor BS to the target anchor BS, or through Anchor BS Switch IE shown in Table 2 for the switch period. Alternatively, even in the process of adding a new active BS to it's the MS's diversity set, the MS can acquire CQICH allocation information of the active BS through a handover control message. The operation of managing the diversity set through the handover control message will not be further described herein because it is not directly related to the present invention.
If it is determined in step 119 that the CQICH allocation information to be used in the target anchor BS has not been received, the MS proceeds to step 121 where it performs a fast switching operation from the serving anchor BS to the target anchor BS and then waits a preset time. Further, the MS determines whether CQICH allocation information is received through a MAP message broadcasted by the target anchor BS within the preset time. A format of CQICH allocation information, i.e., CQICH Alloc IE, in the MAP message including the CQICH allocation information is shown in Table 3 below.
TABLE 3SyntaxSizeNotesCQICH Alloc IECQICH IDVariableIndex to uniquely identify the CQICHresource assigned to the MSThe size of this field is dependenton system parameter defined in DCDFeedback6bitsIndex to the Fast feedback channelregion marked bychannel offsetUIUC = 0Period(p)2bitsA CQI feedback is transmitted onthe CQICH every 2p framesFrame offset3bitsThe MS starts reporting at the frameof which the number has the same3 LSB as the specified frame offset.If the current frame is specified, theMS should start reporting in 8frames.Duration(d)3bitsA CQI feedback is transmitted onthe CQI channels indexed by theCQICH ID for frames if d = 0,the CQICH is deallocated if d = 111,the MS should report until the BScommend for the MS to stop}}}
In Table 3, CQICH Alloc IE allocated in a target anchor BS indicates CQICH allocation information used by an MS to exchange control signals with the target anchor BS, and the CQICH Alloc IE includes CQICH ID, Feedback channel offset for providing actual location information of a CQICH in a CQI field defined in a UL-MAP message, and Frame offset indicating a time at which the MS actually starts reporting a CQI value after being allocated a CQICH. In addition, the CQICH Alloc IE includes Period (p) indicating a period in which the MS reports the CQI value, and Duration (d) indicating an effective time for which the MS can use the allocated CQICH.
If it is determined in step 121 that the CQICH allocation information is not received, the MS proceeds to step 123. In step 123, the MS performs a network re-entry operation with the target anchor BS and then ends the process because it failed to receive CQICH allocation information from the target anchor BS, i.e., because the MS failed to be allocated the CQICH from the target anchor BS even after the MS completed a fast switching operation from the serving anchor BS to the target anchor BS. Herein, the term "network re-entry operation" refers to an operation of acquiring synchronization with the target anchor BS and then performing initial ranging, registration and authentication.
However, if it is determined in step 119 that the CQICH allocation information to be used in the target anchor BS has been received, the MS proceeds to step 125. Also, if it is determined in step 121 that the CQICH allocation information has been received, the MS proceeds to step 125. In step 125, the MS performs a fast switching operation and communication with the target anchor BS through the CQICH allocated thereto, and then ends the process.
The FBSS-based fast switching operation of an MS in the conventional IEEE 802.16 communication system has been described so far with reference to FIG. 1. Next, with reference to FIG. 2, a description will be made of a format of an Anchor Switch Reporting (ASR) slot used in an FBSS-based fast switching operation of an MS in the general IEEE 802.16 communication system.
FIG. 2 is a diagram illustrating a format of an ASR slot used in an FBSS-based fast switching operation of an MS in a conventional IEEE 802.16 communication system. Reference numeral 201 represents transmission of a control signal from an MS to a serving anchor BS, shown on the time axis, reference numeral 203 represents transmission of a control signal from the MS and a target anchor BS, also shown on the time axis. As illustrated in FIG. 2, in the FBSS scheme, the time axis is divided in ASR slots. Each of the ASR slots is comprised of a plurality of, for example, M frames. The number, M, of frames constituting the ASR slot is determined by a BS, and the MS obtains the number, M, of frames constituting the ASR, determined by the BS, through a DCD message.
Reference numeral 205 represents an ASR slot before a fast switching operation performed with the serving anchor BS by the MS, and reference numerals 207 and 209 represent ASR slots in a switch period, for which the MS transmits a control signal used for informing the serving anchor BS of the fast switching operation from the serving anchor BS to the target anchor BS. The switch period includes one or more ASR slots. The number of ASR sots constituting the switch period is also determined by the BS, and the MS finds the number of ASR slots constituting the time switch, determined by the BS, through the DCD message. Reference numeral 211 represents an ASR slot in which the MS performs communication with the target anchor BS after performing a fast switching operation from the serving anchor BS to the target anchor BS, i.e., after completing the switching operation.
In the ASR slot 205 before a fast switching operation, in which the MS is communicating with the serving anchor BS, the MS transmits a CQI value of the serving anchor BS to the serving anchor BS every frame in the ASR slot 205 while performing communication with the serving anchor BS. In the ASR slot 205, if the MS determines that it should a perform fast switching operation from the serving anchor BS to the target anchor BS, the MS waits until termination of the corresponding ASR slot, i.e., the ASR slot 205, where it determined to perform the fast switching operation, instead of immediately performing the fast switching operation at the time where it determined to perform the fast switching.
After termination of the ASR slot 205, the MS informs the serving anchor BS for the switch period that it will perform fast switching from the serving anchor BS to the target anchor BS. In this case, the MS transmits, to the serving anchor BS, a CQI value CA of the serving anchor BS and an indicator IB indicating that it will perform a fast switching operation from the serving anchor BS to the target anchor BS. Although the indicator IB and the CQI value CA are alternately transmitted in FIG. 2 on a frame-by-frame basis, by way of example, a pattern for transmitting the indicators IB and the CQI values CA in the switch period can be variably determined by the MS. At any rate, the MS should transmit the indicator IB and the CQI value CA at least once in a first ASR slot of the switch period.
After the end of the switch period, the MS that performed the fast switching operation from the serving anchor BS to the target anchor BS, transmits a CQI value of the target anchor BS in the ASR slot 211 while performing communication with the target anchor BS.
As described above, in the FBSS scheme, the MS performs a fast switching operation from the serving anchor BS to the target anchor BS by transmitting control signals using a CQICH. However, if the MS fails to be previously allocated a CQICH from the target anchor BS after performing the fast switching operation from the serving anchor BS to the target anchor BS in the switch period, the MS should perform network re-entry with the target anchor BS as described above, causing a delay in connection setup.
If the MS fails to acquire CQICH allocation information from the target anchor BS even after performing the FBSS-based fast switching operation, the MS performs a network re-entry operation with the target anchor BS, causing a connection setup delay. Accordingly, there is a need for a scheme capable of enabling the MS to rapidly set up a connection with the target anchor BS after performing the FBSS-fast switching operation.

System and method for allocating a channel quality information channel in a communication system


A garment hanger having downwardly foldable, pivoted arms uses a spring between the pivoted arms which is compressed when the pivoted arms are in an operative position and a preferably slidable switch/control latch to control off-axis movement of a central portion of the spring to positively control movement of the pivoted arms between an operative position and a folded position and vice-versa. A hollow lower portion of the central portion of the garment hanger provides a shroud which covers all moving parts to improve ease of use and to prevent damage to garments and, if resilient, provides ease of assembly. The relatively few moving parts cooperate without closely fitting or critical dimensions (thus being unaffected by wear on the relatively few bearing surfaces). The functionality of the garment hanger is improved by resiliently conforming to a garment placed thereon and can be shaped, at will, for aesthetic purposes or to simulate the shape of the human shoulders or upper torso. The movement of the pivoted arms between folded and operative positions is easily controlled by manipulation of the sliding switch/control latch with one hand, particularly for insertion into garments having neck apertures of limited dimensions.

1. Field of the Invention
The present invention generally relates to devices by which garments can be hung for storage and, more particularly, to garment hangers which can be folded or collapsed for storage, packing, or insertion into or removal from a garment.
2. Description of the Prior Art
Many garments intended for wear on the human torso have often presented problems of storage when not in use. Outside China and some other countries of Asia (where such garments were traditionally designed to be folded into a flat shape for storage in boxes or cabinets) problems of storage arise from the fact that such garments are cut from patterns of cloth and fabricated in a manner which can generally follow the compound curves of the human shoulders and upper torso. Accordingly, devices (commonly known as clothes hangers) for hanging garments from a fixed structure such as a hook or horizontal rod have been developed which, to a greater or lesser degree follow the shape of the human shoulders to avoid excessive distortion or wrinkling of a garment during storage.
However, to provide such a function by simulation of the shape of the human shoulders, such garment hangers have been necessarily of dimensions which are inconveniently large or bulky and generally of rigid form, particularly when made from light-weight materials such as wire. Therefore, the hangers themselves are difficult and inconvenient to store and efforts to reduce weight and bulk generally result in structures which can become tangled with each other and/or cause damage to the garments stored thereon.
Further, to remove the garment from a garment hanger, it is generally necessary to remove the garment hanger from the fixed hook or rod structure, separately remove the garment from the hanger and to replace the garment hanger on the fixed hook or rod. These actions generally require both hands to be used and may be inconvenient and somewhat time-consuming.
An additional difficulty is presented by the fact that many garments in current styles have a neck opening of limited size or which may even require the neck opening to be stretched over the wearer's head when donning or removing the garment. Rigid garment hangers usually must be inserted from the bottom (e.g. waist or lower hem) of such garments which is particularly inconvenient, particularly for one-piece dresses and the like.
Folding garment hangers are known in which the folding function is intended to facilitate storage or insertion into a garment. However, since weight and bulk of the garment hanger is of concern, early designs provided arms which folded upward from an operative position toward an upper portion of the garment hanger, generally in the form of a hook or other arrangement for supporting the garment hanger, which engaged a fixed hook or rod structure, alluded to above. Such an arrangement provided for the arms to pivot downward into an operative position against rigid stops in the garment hanger structure to more reliably support the weight of the garment. However, this feature also complicated the process of removing the garment hanger from the garment as well as placement of the garment thereon and increased the risk of damage to the garment since folds of cloth could become pinched between portions of the hanger structure, including the stops, and snagging of the garment by the arms of the garment hanger. It can readily be appreciated that for removal of a garment from such a garment hanger, that any snagging of the garment on the arms of the garment hanger tends to increase the dimensions of the garment hanger.
Garment hangers in which the arms fold downwardly from an operative position have presented the problem of reliable support of the weight of the garment which has heretofore required trade-offs in regard to the inconvenience of placing the arms of the garment hanger in an operative position after the garment hanger is inserted into the garment. Known designs of this type also provide rigidity once the garment hanger is adjusted into an operative form with the arms extended and requires actions similar to those discussed above in connection with rigid hangers (and usually requiring use of both hands) for removing the hanger from the garment. For example, U.S. Pat. No. 5,383,584 and U.S. Design Pat. No. Des. 355,771 to Adams have a hinged frame which latches into an operative configuration. While the latch can be released with one hand, allowing the arms to fold downward, the arms must be raised manually to an operative and latched position by gripping them with both hands through the fabric of the garment which is especially difficult if the garment is damp or wet. Failure of the latch or accidental disengagement thereof will also render the hanger apparatus inoperative and allow the garment to fall therefrom.
Likewise, U.S. Pat. No. 5,397,037 to Ozawa requires both manual raising of the arms to an operative position simultaneously with both hands and, to remove the hanger from the garment, the pressing of a hook portion toward the body of the hanger to release a detent to allow the arms to again be folded downwardly. The Ozawa design also requires a relatively large plurality of intricate and close-fitting, interacting parts which are subject to wear in order to reconcile the downward folding arm structure with relatively secure holding of the garment; the latter tending to diminish greatly with wear of the parts, particularly the detent structure on which the design relies. The many moving parts which engage each other closely with sliding motions are also particularly likely to snag or otherwise engage the fabric of the garment (particularly if the fabric is thin) and thus to damage the garment, malfunction during insertion into or removal from the garment and to require a protracted and complicated process to disengage the hanger from the garment during which damage the likelihood of damage to the garment is greatly increased.
Horizontally folding hangers are also known, such as U.S. Design Pat. No. Des. 349,410 to Morales-Rivera. However, horizontally folding garment hangers are usually intended only to facilitate storage of the hanger and are generally awkward to fold for this purpose and/or less than optimally secure for the hanging of garments. They are especially awkward to unfold to an operative configuration after insertion into a garment since the unfolding operation, in its intermediate positions necessarily involves a three-dimensional volume of substantial dimensions (within the garment) rather than motion substantially in a plane. Horizontal forces applied to a garment hanging therefrom (as is a common action when a person is looking to make a choice among garments hung in a closet or cabinet) may cause sudden folding of the hanger to occur and disengagement of the garment from the hanger.
Additionally, in regard to known folding garment hangers, the folding function thereof often precludes formation of the arm portions or the overall hanger into a shape which optimally supports the shape of the garment or which is aesthetically pleasing, itself. For example, the patents to Adams and Ozawa, discussed above, are constrained to a utilitarian, substantially planar shape which does not simulate the shape (e.g. in front-to-back width) of the human shoulders and a fixed slope which may or may not closely match the shape of the corresponding portions of the garment. These concerns are important for expensive garments which are fabricated or tailored to closely match the shoulder contours of a wearer or which have a small neck aperture. In the latter case, arms which are too nearly horizontal in an operative position may stretch portions of the garment at the shoulder portions of the garment near the arm apertures/sleeves while too great a slope tends to stretch the neck aperture of the garment.


The invention concerns a method for transferring data from a plurality of serial channels (1-6) on a parallel channel. To each serial channel is associated a buffer memory in which are stored the data arriving on the serial channel. Some of the serial channels (1-2) operate at a high speed and the others (3-6) at lower speeds. The method consists in processing a buffer associated to a channel as many times less as the channel is slower than a high speed channel over a number of periods equal to the high speed divided by the speed of the processed channel.

The present invention relates to multiplexers used in computer systems and more particularly to a multiplexer comprising an important number of asynchronous channels which can function at different transmission speeds.
FIG. 1 shows a simplified schematic diagram of a multiplexer in a computer system. The elements of the multiplexer are included between two vertical dashed lines. The multiplexer comprises a plurality of UARTs (Universal Asynchronous Receiver/Transmitters) 10 connected through serial communication lines, such as RS232 lines, to exterior elements 12 such as terminals, peripherals or other computer systems. A first-in first-out (FIFO) buffer 14 is associated to each of the UARTs. Hereinafter, a group including a serial connection, a UART, and a FIFO will be called a channel C and only the case where the exterior elements 12 transmit data will be studied.
A data and address bus B interconnects each channel, with a microprocessor (CPU) 16, a memory (RAM) 18, and an interface circuit (BIC) 20 between bus B and an external bus of the computer system.
It can be considered that in the FIFOs, data are piled up by order of arrival, the bottom datum (the first one) being withdrawn from the pile and presented on the data bus when the FIFO is read-selected by an address. The read data is then transferred to the RAM 18 before it is transferred to the external bus. It will be supposed hereinafter that the data are characters.
The communication protocol of each of the channels, especially the transmission speed, is determined by a register (not shown) of the associated UART, which can be programmed through bus B. The transmission speed is given by a signal F provided to each UART by a clock circuit (CK) 22 which can eventually provide an additional signal 12 of programmable frequency. It is usual to have a transmission speed comprised between 300 bauds and 38.4 kilobauds. This transmission speed, hereinafter channel speed, can attain the frequency of signal F. The slower transmission speeds are obtained in the UARTs from signal F by dividing its frequency by powers of 2.
Presently, it is attempted to increase the number of channels and/or the maximum transmission speed without increasing the power of the microprocessor, that is the frequency at which the microprocessor functions, or to choose a less powerful microprocessor for a given number of channels. This is attempted knowing that the multiplexer will be unable to manage all the channels if the latter all receive characters at the maximum speed, but also knowing that it is more likely to only have a limited number of channels operating at high speed. It will be supposed hereinafter that the multiplexer is in this more realistic situation.
The incapacity of managing the channels results in an overflow of the FIFOs due to the fact that the microprocessor does not have the time to transfer the characters into the RAM, or results in an overflow of the RAM due to the fact that the microprocessor does not have the time to transfer the characters to the external bus. When a FIFO overflow occurs, the corresponding UART transmits to the associated circuit 12 a signal, Xoff, indicating to the latter that it must stop transmitting. In general, signal Xoff is sent as soon as a predetermined fraction of the FIFO is filled in order to leave a security margin, because circuit 12 could still transmit a few characters after receiving signals Xoff or even ignore this signal if the circuit is designed to not use this signal. The FIFOs are generally of small size, for example 16 characters, and signal Xoff is sent as soon as a FIFO is half full.
The multiplexer of FIG. 1 can conventionally operate according to one of three modes according to the programming of the UARTs, and of clock CK (for the third mode).
A first mode is an interrupt per character mode. In this mode, as soon as a character arriving on a channel is written in the corresponding FIFO, the UART asserts an interrupt request I1 which is provided to an interruption input IRQ of the microprocessor through an OR gate 24. At the same time, the UART writes in a not shown register data corresponding to the number of the channel. Then the microprocessor interrupts its task, reads in the above register the number of the channel to process, and polls the corresponding channel. By polling a channel, it is understood that it is checked whether the corresponding FIFO is empty and, if not, transferring its content to the RAM.
FIG. 2 symbolically shows processing durations according to this first mode. Characters arrive at random moments t. From a moment t, an interruption is generated and an interruption processing time interval Tf is started. At the end of interval Tf, a character processing interval Tc starts. If a character arrives when the preceding character has not yet been processed, the interruption is memorized and is processed at the end of interval Tc of the preceding character.
This first operating mode is very disadvantageous. Indeed, the interruption processing time Tf is such greater than the character processing time Tc. For example, if the microprocessor is a series 68000 of MOTOROLA operating at 16 MHz, time Tf is approximately equal to 4Tc. Furthermore, the arrival of a character in the FIFO of a channel operating at a maximum frequency of 38.4 kilobauds is greater that Tf+Tc; hence, for a same interruption, only one character at the time can be processed. Thus, supposing that a continuous flow of characters arrives on the channels, the processing efficiency of the characters is EQU Tc/(Tf+Tc).apprxeq.1/5.
A second possible operating mode is the continuous mode. In this mode, the UARTs do not send interruptions and the microprocessor executes in an endless loop a main program comprising a sub-program for polling all the channels. It is chosen, either by inserting delays in the main program if the execution time of the latter is too short, either by multiplying the number of polling sub-programs in the main program if the execution time of the latter is too long, to render the means time Te elapsed between two polls substantially equal to the time its takes to fill a FIFO at the maximum transmission speed to the point an Xoff signal is sent. Hereinafter, this time will be called "minimum time for partial filling". This time Te thus varies from one poll to the other as a function of the amount of tasks to be done by the microprocessor in the main program and in the subprogram(s).
FIG. 3 symbolically shows the time elapsed during the execution of the loops of the main program. It is supposed in this figure that the main program comprises one polling subprogram which is executed at the start of the main program. Moments t0, t1 and t2 are shown indicating the beginning of each main program execution.
At moment t0, the character flow on the channel is low, the execution time .SIGMA.T of the sub-program is low as well as the total time Te=t1-t0 for executing the loop as the main program is then only essentially in charge of transferring a low number of characters stored in the RAM to the external bus.
At moment t1, it is supposed that the character flow is more important. Not only time .SIGMA.T increases, but also the transferring time of the characters from the RAM to the external bus. Thus, the time increase of interval Te=t2-t1 is greater than the only time increase of interval .SIGMA.T.
This second operating mode is much more convenient than the previous one because the microprocessor must not process interruptions. However, if the character flow is great, time Te can become greater than the minimum time of partial, or even total, filling. In this case, a FIFO of a maximum speed channel overflows, or at least, attains the filling state which causes a signal Xoff to be sent, which is tried to be avoided.
A third operating mode is a periodical interruption mode. This operating mode is similar to the previous one, except that the polling sub-programs are periodically executed. In order to achieve this, an interruption signal 12 is provided to the microprocessor, the period of which is equal to the minimum time of partial filling of a FIFO. This interruption signal 12, as shown in FIG. 1, is provided by clock CK to the input IRQ of the microprocessor through OR gate 24. The frequency of the interruption signal 12 is obtained by dividing the frequency of signal F by a factor which can be programmed in the clock circuit through bus B.
FIG. 4 symbolically shows a period T.sub.1 of interruption signal 12. This period is sub-divided in a plurality of time intervals. At the beginning of the period, a constant time interval Tf starts. This time interval corresponds to the interruption processing time by the microprocessor. This time interval is followed by time intervals T1, T2. . . Tn corresponding respectively to the polling of each of the channels Cl to Cn. The intervals T1 to Tn, the sum of which is equal to .SIGMA.T, are each sub-divided in a constant time interval Ts which corresponds to the time necessary for selecting a channel and in a time interval .SIGMA.Tc which is the sum of the times Tc for treating the characters stored in the FIFO of the channel. A variable time interval Tr occupying the remaining of period T.sub.I, is the time remaining for the microprocessor to achieve its other tasks, especially transferring the characters from the RAM to the external bus. When interval Tr is sufficiently great, the microprocessor can at each period transfer the whole content of the RAM to the external bus. But if it is too small, this transfer must be distributed on a plurality of periods, hoping that the RAM does not continue to fill too quickly.
With respect to the previous mode, this operating mode has, for each period T.sub.I, an additional inactivity time Tf corresponding to the processing of an interruption. This operating mode is thus slightly less efficient than the previous one but it is more reliable because period T.sub.I does not vary. The means character processing efficiency with respect to a period T.sub.I is expressed by ##EQU1## wherein n designates the number of channels and m the mean number of characters arriving per period. It will be noted that this efficiency increases with m and thus that its value is the greatest when all channels receive characters at maximum speed. This mode happens to be the most efficient when all channels are operating at maximum speed.
However, as previously mentioned, it is much more likely that a limited number (eventually null) of the channels operate at maximum speed, the other channels operating at lower speeds. Then, the above efficiency decreases substantially and represents an obstacle if it is desired to increase the number of channels. If it is supposed, for example, that channel C1 corresponding to interval T1 operates at maximum frequency, that period T.sub.I corresponds to the arrival of 8 characters at this frequency in the FIFO, and that channel C2 corresponding to interval T2 operates at a speed 8 times smaller than the maximum speed, at each period T.sub.I, 8 characters will be processed during interval T1 and only one during interval T2. Actually, an interval Ts will have been spent for 8 characters and an additional interval Ts will have been spent for one character. If other channels operate at still smaller speed, additional intervals Ts will be spent for no characters. It will be noted that, in such a case, term n.multidot.TS in the expression of the efficiency r increases with respect to terms m.multidot.Tc, which causes a decrease of the efficiency.
Thus, the more channels there are operating at low speeds with respect to channels operating at high speeds, the more the character processing efficiency decreases and the more the possibility of managing additional channels is diminished.


An improved hammock stand including a central base pipe, a pair of canted upstanding arm pipes, a set of four foot extension pipes, and a pair of connector assemblies to which the individually mountable/demountable feet extension, arm and base pipes may be telescopingly mounted. Each connector unit has a pair of extension pipes welded to a bowed crosspiece pipe oriented concave down. The extension pipes are identical in character and disposed on the crosspiece pipe such that the pipes lie in a vertical plane which passes transversely through the crosspiece at the center of the bend. The arm and base pipes telescopingly mount onto the extension pipes; the foot extension pipes telescopingly mount onto the crosspiece pipe so that they are canted downwardly and outwardly from about one to about five degrees. The bend in the crosspiece pipe creates a vertical lift beneath the connector assemblies and the central base pipe thereby compensating for uneven ground surface levels, and stabilizing and cushioning the support of the hammock. In addition, the outer diameter of the crosspiece and extension pipes when compared to the inner diameter of the feet, base and arm pipes, provide enough clearance such that the feet, base and arm pipes may be easily slipped on and off the crosspiece and extension pipes in order to prevent jamming and, thus avoiding a problem of not being able to disassemble the unit once it has been assembled.

Hammocks are suspended from two spaced-apart connector points. Where there are no natural and properly spaced objects, such as trees, to secure a hammock connecting ring, walls or posts may be used. However, where the hammock is desired to be moved from place to place, hammock supports or stands are employed. One popular type of stand is a "sled" type which employs two spaced-apart rails and raised ends which meet at a common point above ground. These ends contain rings or S-hooks for securing the ends of the hammock.
Another type of stand is the "single rib" type. Both types are typically made of light gauge steel coated with plastic for rust protection.
The single rib-type stand includes a central rib pipe, and two upstanding arms which are connected by a foot connector assembly. The foot connector assembly 5, illustrated in FIG. 1, comprises a single 4-foot crosspiece 10 to which is welded a single "C"-shaped bent tube 12 which is placed with a concave surface 14 upwardly. The tube 12 is welded, at a plurality of joints 16 and 18, to the crosspiece to form the foot. Also, both ends of the tube 12 are tapered with a smaller end 20 and a somewhat enlarged medial section 22 so that the center rib pipe (not shown) and the upstanding arm 24 may fit thereon.
Turning now to FIG. 2, which depicts a partially sectional view of the assembly 5. A serious disadvantage of the assembly 5 is that the arm 24 and a center rib pipe 26 wedge so tightly on the connector that they cannot be removed from the connector after they are installed. In addition, the plastic sheathing becomes easily scratched and the thin metal tubing rusts easily. The lift of the stand is very short, and its inability to disassemble makes it an undesirable design. In addition, on uneven ground the straight cross-piece is unstable. The thin wall construction is not rigid and the hammock experiences bouncing and cannot support properly very heavy or multiple users.
Accordingly, there is a clear need in the art for a hammock support structure which overcomes the problem of currently commercially available units.


The invention provides a method and system for transmission and frequency domain equalization for wideband CDMA communications by providing at least one spread sequence portion, and inserting a cyclic redundancy to the spread sequence to form a transmitted baseband sequence. The invention further provides a method and system for converting a plurality of receive samples from at least one spread sequence portion into a plurality of frequency domain samples, determining a plurality of frequency domain equalization weights for the frequency domain samples, and determining a time domain signal estimate based on the frequency domain equalization weights and frequency domain samples.

Code-Division Multiple Access (CDMA) is a well-known spread-spectrum physical layer technology for cellular systems. CDMA is currently used in the US IS-95 cellular standard and forms the foundation for some so-called 3rd generation cellular systems, such as IS-2000. Third generation (3G) systems are designed to support higher data rates and a wide range of new services. However, the demand for even higher data rates is expected to lead to the development of 4th generation systems in the years following the deployment of 3G.
There are several known techniques for increasing the peak per-user data rate in a CDMA system. First, the concept of multi-code CDMA involves simultaneously allocating multiple Walsh-code channels to a single user, thereby multiplying the peak data rate that can be delivered to any one user at a time. Second, increasing the chip rate, and therefore the system bandwidth, will directly increase the peak per-user data rate. Third, the use of higher-order modulation on each of the Walsh-code channels provides another method for increasing the data-carrying capacity.
Current cellular CDMA systems operate in relatively low bandwidths (1.25 MHz), and use low-order modulation with aggressive error control coding. On the forward link of these systems, the performance with a RAKE receiver is generally viewed as adequate for typical land-mobile cellular channels. However, if the previously mentioned techniques are used to significantly increase the data rate, the RAKE receiver can be shown to provide sub-optimal performance in severe multipath channels. Much of the reason for this sub-optimal performance can be traced to the fact that a multipath delay spread channel destroys the orthogonality of the Walsh-code channels. Walsh codes are orthogonal to each other, but have nonzero autocorrelation and nonzero cross-correlation properties. This loss of Walsh code orthogonality causes the output of a particular RAKE finger to contain significant energy (i.e., interference) from the multipath components having different arrival times. This interference, from other multipath components, is called intracellular interference. Intracellular interference becomes more severe as the channel multipath delay spread increases. As the system bandwidth is increased, the chip-span of a given multipath delay spread channel increases proportionally, which increases the required number of RAKE fingers in the RAKE receiver. As the number of multipath components resolved in the receiver increases, intracellular interference increases, which can further degrade RAKE performance.
As an alternative to a RAKE receiver, time-domain adaptive equalization is a technique for suppressing forward link intracellular interference caused by loss of Walsh code orthogonality. In contrast to a RAKE receiver, a time-domain MMSE adaptive equalizer balances the need to restore Walsh channel orthogonality with noise enhancement, thereby reducing the intracellular interference on the CDMA forward link. However, as system bandwidth increases, time-domain techniques known in the art for MMSE adaptive equalization have a complexity that grows rapidly with the channel length. A larger signal bandwidth typically results in a longer channel length, as measured in chip-times. As higher and higher system bandwidths are employed in future CDMA systems, equalization strategies having complexities lower than the time-domain techniques for MMSE adaptive equalization will be needed.
Therefore, it would be desirable to have a method and device for providing improved transmission format and equalization strategies to enable CDMA systems to support much higher data rates in future broadband wireless systems. Further, it would be desirable that the improved equalization strategies provide for the complexities and problems mentioned.

Method and system for transmission and frequency domain equalization for wideband CDMA system


In a mesh communications network, in which working and protection paths may be established, channels used to carry protection traffic between nodes are shared across multiple protection paths. Channels need only be shared if sharing does not adversely impact network usage. If working and protection paths become susceptible to single points of failure, channels need not be shared.

The need to provide reliability between communications nodes on networks has been known and understood for some time. As such, network designs often provide for protection paths across such networks in the event of failures.
For example, synchronous optical networks ("SONET") and asynchronous transfer mode ("ATM") networks include protection switching used to provide 1+1, 1:1, 1:n, or m:n redundancy for provisioned paths across SONET and ATM networks. In the event of a fault, exemplified by failed or degraded signal, traffic from a working path may be switched to a provisioned protection path, thereby limiting the effects of a fault.
In the past, existing protocols have required manual configuration of working and protection paths across the network. Network topologies were relatively simple, and configuration was straightforward. More recently conceived networks allow paths to be established dynamically, and automatically as required. This provides great flexibility in configuring the network to provide working and protection paths only as required.
However, provisioning network resources to effectively provide sufficient redundancy for protection switching without unnecessarily reserving network resources presents new challenges for network operators and architects. This is particularly so for modern mesh networks, in which each network node may have links to multiple adjacent nodes, and multiple paths between source and destination nodes exist.
Accordingly, there is a need for new network protocols, methods and devices that make efficient use of network resources while allowing protection switching.

Methods, devices and software for combining protection paths across a communications network


An apparatus for identifying the optimum jet for a carburetor which includes a general annular first member having a plurality of first graduations disposed about a peripheral portion thereof, a general arcuate second member having a plurality of second graduations disposed for cooperation with the first graduations, and members coupling the first and second member permitting relative rotation and selective alignment of the first and second graduations. One of the plurality of graduations are arrayed on a linear scale corresponding to relative air density and the other of the plurality of graduations being arrayed on a scale corresponding to respective jet flow and or identifying numbers. The members coupling the first and second members may include a plurality of arms disposed at angularly space intervals. There may be three such arms and they may be fixed to the arcuate member. The annular member may include an offset peripheral portion that is nested between with the three arms.

The invention relates to apparatus for optimizing the performance of internal combustion engines equipped with a carburetor and particularly for selecting the optimum main jet or nozzle for a carburetor.
The selection of the nozzles or jets for a carburetor used with an internal combustion engine has a marked impact on the performance of the engine. More specifically, the fuel economy, top speed and the vehicle acceleration are markedly influenced by the nozzle selection. The conventional carburetor does not vary fuel delivered to the engine when the air density changes.
A reciprocating internal combustion engine draws the same volume of air during the intake stroke despite the ambient conditions. The weight and density of the air drawn into the cylinder will vary substantially with atmospheric pressure and temperature.
Relative air density gauges have been employed with various engines. One common application is in the stock car racing field although the apparatus is also commonly used for sprint cars, snowmobiles, go carts, and motorcycles. A typical relative air density gauge has a small bellows with air sealed inside the bellows. An increase in air pressure compresses the bellows which is coupled to a needle that is mounted for rotation. Higher atmospheric pressure compresses the bellow and causes the movement of the needle to a higher level on an arcuate scale. Lower atmospheric pressure allows the bellows to expand and causes the needle coupled to the to the bellows to move to a lower position on an arcuate scale. Similarly, cooling of the ambient air cools the air in the bellows and this causes the bellows to contract which results in a higher indication on the scale by the needle. Heating of the ambient air causes the heating of the air within the bellows and this causes the bellows to expand which results in a lower indication on the scale by the needle.
Those skilled in the art will recognize that if the density of the air increases and the quantity of fuel supplied to the engine is constant, the mixture will be lean. This will cause a power loss and could damage the engine. Addition of the optimum amount of fuel, by using a larger jet or nozzle results in a power increase and less risk of engine damage.
The utilization of the air density gauge involves a calculation or trial and error to optimize the jet or jets for the carburetor. Many people are not comfortable with making a mathematical calculation to determine the correct jet size.
It is an object of the invention to provide a construction that will enable even mathematically unsophisticated users to more precisely determine the correct jet or nozzle size.
It is an object of the invention to provide apparatus that will physically cooperate with an associated relative air density gauge.
It is an object of the invention to provide apparatus which is inexpensive to manufacture.
Still another object of the invention is to provide apparatus that may be mounted in a manner that will facilitate use of the apparatus.


Methods, compiler apparatus and a computer program product for compiling UPC source code are disclosed. UPC-unique constructs are converted into C-level form. The C-level constructs are inserted into the source code to form a combined code. The combined code is translated into an intermediate form, wherein any surviving UPC-unique components are discarded. All UPC-unique data or statements are converted to a form that can be handled by general compiler architectures, yet retain UPC properties. The resultant intermediate form is converted to compiled machine code. The generation of C-level constructs occurs at a compiler front end module, avoiding difficulties in intermediate code handling.

A compiler generally includes a frontend that translates source code into an intermediate form. An intermediate form processor optimizes the intermediate form. A backend then converts the optimized intermediate form code into, typically, machine language code. A reference, that teaches source-to-source translation and translation after mapping to a smaller intermediate code, is A. V. Aho, R. Sethi, and J. D. Ullman, "Compilers Principles, Techniques, and Tools", Addison-Wesley Publishing Company, Reading, Massachusetts, 1988. Reference is made to chapter 1, that introduces compiling, to chapter 3, section 1 regarding lexical analyzers, to chapter 4, sections 1 and 2 dealing with parsers and context-free grammars, to chapter 8, section 1 dealing with intermediate languages, to the introduction of chapter 9 on code generation generally, and to the introduction to chapter 10 on code optimaization. intermediate compile mechanism that performs wide compilation functions without changing existing program makefiles. The intermediate compile mechanism supports cross-module inline substitutions and passing of arguments to registers, to improve execution times of executable programs.
U.S. Pat. No. 6,253,370 (Abadi et al), issued Jun. 26, 2001, teaches a method and apparatus that can be applied in a pre-compiler environment to annotate a computer program to facilitate subsequent processing of a program. Code representing the program is generated at a first computer system. Annotations are generated for the code that provide information about the code. At a second computer, the code is processed according to the information provided by the annotations. The annotations, for example, can indicate a control flow graph representing a flow of execution of the code. Also, the information provided by the annotations can be a register allocation that maps data structures of the code to registers of the second computer system.
UPC is a parallel extension to ANSI C, based on a distributed, shared-memory programing paradigm. It provides a common syntax and semantics for writing high-perfomance, explicitly parallel programs in C. An example of UPC is taught by T. A. El-Ghazawi, W. W. Carlson, and J. M. Draper, "UPC Language Specifications V1.1", issued Mar. 24, 2003, as a joint work, by the University of California Berkerley and the National Energy Research Scientific Computing Center, Lawrence Berkely National Laboratory, Office of Science, US Department of Energy.
UPC has a number of constructs in addition to ANSI C. They can be classified into three categories:    1. Data types—shared, strict and relaxed with blocking factors.    2. Statements—forall    3. Synchronization constructs—barrier, lock, etc.
A convenient approach to implementing UPC compiler using an existing C-compiler, is to define a UPC run-time library that can be targeted by a compiler in generating code. The amount of code generation required of the compiler is substantial, involving generation at points of declaration, initialization, read and write of shared entities. In a document authored by Wei Chen, "The Berkely UPC Compiler", published at the Open64 User Forum, International Symposium on Code Generation and Optimization, San Francisco, Calif., in March 2003, it is taught that proxy data structures are used to represent shared entities, and communication for read and write of the shared entities is carried out with reference to these proxy (but ordinary C) data structures. Manipulating (e.g. initializing proxy, initializing remote data, communication via proxy) a proxy involves manipulating its internal fields and values, which has to be reflected in the generated code. In order to be compiler independent, the Chen reference chooses a C-level intermediate form in which reads and writes are transformed into calls in a runtime library.
The need exists, however, for a compiler to further ease the code generation aspects of translating UPC programs and to correctly handle UPC program constructs. This is particularly so for nested forall statements.

Compilation of unified parallel C-language programs

International Business Machines Corporation


A novel and useful pressure sensor array incorporating sensor elements constructed from electrically conductive film as a substrate. Examples of commercially available electrically conductive (i.e. piezoresistive) film include Velostat and Linqstat. A wearable device is described incorporating an array of pressure sensors with flexible properties and a biocompatible material interface between the sensor elements and a user's skin. The pressure sensor array uses the electrically conductive film as a substrate and places a pair of conductors in a suitable configuration to form individual sensor elements. The sensor elements detect the change in resistance of the electrically conductive film when pressure is applied thereto. The sensor elements may be implemented in an interdigitated or opposing configuration. The sensor array also comprises a mechanical interface on top of the sensor elements for transferring or focusing the applied pressure to the electrically conductive film.

High blood pressure is a common condition in which the long-term force of the blood against your artery walls is high enough that it may eventually cause health problems, such as heart disease. Blood pressure is determined both by the amount of blood your heart pumps and the amount of resistance to blood flow in your arteries. The more blood your heart pumps and the narrower your arteries, the higher your blood pressure.
One can have high blood pressure (i.e. hypertension) for years without any symptoms. Even without symptoms, damage to blood vessels and one's heart continues and can be detected. Uncontrolled high blood pressure increases one's risk of serious health problems, including heart attack and stroke. High blood pressure generally develops over many years, and it affects nearly everyone eventually. Fortunately, high blood pressure can be detected.
Currently, cardiovascular diseases represent a large proportion of all reported deaths globally. These diseases are considered a severe and shared risk, with a majority of the burden in low and middle-income countries. A major factor that increases the risk of heart failures or strokes, speeds up hardening of blood vessels and reduces life expectancy is hypertension or high blood pressure.
Hypertension is a chronic health condition in which the pressure exerted by the circulating blood upon the walls of blood vessels is elevated. In order to ensure appropriate circulation of blood in blood vessels, the heart of a hypertensive person must work harder than normal, which increases the risk of heart attack, stroke and cardiac failure. Eating a healthy diet and exercising, however, can significantly improve blood pressure control and decrease the risk of complications. Efficient drug treatments are also available. It is therefore important to find persons with elevated blood pressures and monitor their blood pressure information on a regular basis.
During each heartbeat, the blood pressure varies between a maximum (i.e. systolic) and a minimum (i.e. diastolic) pressure. A traditional noninvasive way to measure blood pressure has been to use a pressurized cuff and detect the pressure levels where the blood flow starts to pulsate (i.e. cuff pressure is between the systolic and diastolic pressure) and where there is no flow at all (i.e. cuff pressure exceeds systolic pressure). It has been seen, however, that users tend to consider the measurement situations, as well as the pressurized cuff tedious and even stressing, especially in long-term monitoring. In addition, the well-known white-coat syndrome tends to elevate the blood pressure during the measurement which leads to inaccurate diagnoses.
The use of wearable devices for monitoring body physiological parameters (e.g. blood pressure, heart rate (HR) pulse, body temperature, blood glucose level, movement patterns, etc.) non-invasively, continuously and/or intermittently for extended periods of time are becoming popular as a way to monitor and improve health.
Traditional blood pressure measurements require inflatable cuffs, which are gradually deflated from a state of full vessel occlusion to a lower pressure while listening using a mechanical sensor (e.g., stethoscope) to the sounds generated by the blood flow eddies in the vessel. An advantage of this method is its relative robustness to movements, while a disadvantage is its large form factor and the need for either manual inflation by the user or an automatic pump, which requires large quantities of energy. Since energy efficiency and small form factor are major requirements in wearable devices, inflatable cuff blood pressure sensing is not a useful paradigm in this space.
Prior art blood pressure measurement devices have significant disadvantages. First, the positioning or placement of the sensor on the radial artery is challenging to the user. Second, the sensor typically requires calibration in order to obtain correct readings. Third, the signal to noise ratio (SNR) obtained from the sensor might not be sufficient to obtain reliable blood pressure readings.
There is thus a need for a mechanism capable of continuously measuring and monitoring blood pressure that overcomes the disadvantages of traditional prior art devices and methods. For example, the mechanism of measuring blood pressure should not require the use of an inflatable cuff with its associated high energy requirements. In addition, the mechanism should be able to sense the blood pressure waveform on one or more of the arteries in the arm (i.e. the radial and ulnar arteries).

Blood pressure measurement system using force resistive sensor array


An image vibration reduction device has a vibration reduction optical system movable for reducing an image vibration, a guide member for movably guiding the vibration reduction optical system in a predetermined direction, and a driving force generating device for generating a driving force for moving the optical system. Disposed on substantially the same plane are a centroid of the whole movable portion including the vibration reduction optical system moved when reducing the vibration, a portion where a load is produced between the movable portion and the guide member, and a position where the driving force of the driving force generating device is generated. A moment produced due to a disposition positional deviation can be thereby restrained.

1. Field of the Invention
The present invention relates to an image vibration reduction device for reducing an image vibration of an object image in an optical apparatus such as a camera, a telescope and a video camera.
2. Related Background Art
An image vibration reduction device reduces a deflection of an optical axis with respect to a photographing screen by moving an image vibration reduction optical system incorporated as a whole or a part of a photographic optical system of an optical apparatus such as a camera, a telescope and a video camera, in such a direction as to offset a vibration of a camera shake caused by a photographer.
FIGS. 9 and 10 are explanatory views each showing a structure of a prior art image vibration reduction device incorporated into the camera.
In an example shown in FIG. 9, in an interior of a lens barrel unit L, a lens holder 122 for holding an image vibration reduction lens 121 and a lens frame 123 for supporting the lens holder 122 are so disposed as to be movable in two-dimensional directions, i.e., X- and Y-directions within the plane orthogonal to an optical axis. The lens frame 123 of an image vibration reduction optical system is supported by wires 136, 137, 138, 139 provided in parallel to the optical axis and composed of resilient members, which are fixed to four positions of the lens frame 123.
Upper and right sides of the lens frame 123 are formed with a coil support frame of a voice coil motor, and coils 124, 125 of the voice coil motor are fixed to the lens frame 123, thus constituting the voice coil motor. The lens frame 123 is driven by this voice coil motor, thereby moving the above-mentioned image vibration reduction optical system.
On the other hand, also in an example shown in FIG. 10, in the interior of the lens barrel unit L, a lens holder 152 for holding an image vibration reduction lens 151 is movable in two-dimensional directions, i.e., X- and Y-directions within the plane orthogonal to the optical axis. A Y-directional stage 153 and an X-directional stage 155 that constitute the image vibration reduction optical system are supported by guide portions 153-1a, 153-1b, 155-1a, 155-1b, shafts 153-2a, 153-2b, 155-2a, 155-2b, and coil springs 154-1a, 154-1b, 154-2a, 154-2b, 156-1a, 156-1b, 156-2a, 156-2b.
An upper side of the Y-directional stage 153 is formed with a coil support frame of a voice coil motor, and a coil 157 of the voice coil motor is fixed to the coil support frame of the voice coil motor, thus constituting the voice coil motor. Similarly, a left side of the X-directional stage 155 is formed with a coil support frame of the voice coil motor, and a coil 158 of the voice coil motor is fixed to the coil support frame of the voice coil motor, thus constituting the coil voice motor. The Y- and X-directional stages 153, 155 are driven by these voice coil motors, thereby moving the above-described image vibration reduction optical system.
By the way, if a centrobaric position of the movable portion moved by the voice coil motor, a portion where a load between a guide device and the movable portion is produced, and a portion where a driving force of the voice coil motor is produced, exist in positions spaced far from each other, it follows that a moment is caused with the movement. If this moment has a small value, there might be no problem. In the case of a large value, however, a problem may arise.
For example, in the image vibration reduction device having a structure illustrated in FIG. 9, when an image vibration reduction lens 121 is moved at a high speed, the wires 136, 137, 138, 139 are buckled and deformed due to the moment described above and therefore do not function as the resilient members.
Further, in the image vibration reduction device having a structure illustrated in FIG. 10, when the image vibration reduction lens 121 is moved at the high speed, the guide portions 153-1a, 153-1b, 155-1a, 155-1b and the shafts 153-2a, 153-2b, 155-2a, 155-2b are inclined and contact each other, with the result that relative motions between the guide portions and the shaft are hindered by frictions therebetween. Also, such an increase in the moment leads to an increment in terms of a frictional load between the guide portion and the shaft. As a result, a rise in electric power consumed is brought about.
Accordingly, under such circumstance, it is quite difficult to reduce the vibration by moving the image vibration reduction lens to a desired position, resulting in a such problem that the image vibration can not be reduced.


A bone cutting jig system for forming and shaping spinal implants is shown. The system includes a first cutting jig having a bed with a clamp mechanism for clamping donor bone positioned on the bed. A cutting guide insert or plate is received in fixed orientation on the bed and is further provided with two spaced cutting blade cutting guides which are configured for transversely cutting out a segment of the donor bone with a reciprocating saw or router to a predetermined shape to provide a custom fit lumbar, cervical or thoracic inter-body fusion implant. A second cutting jig is provided for making additional cuts to the preformed implant for custom fit to particular implant applications.

1. Field of the Invention
The invention relates to an instrument for cutting and otherwise shaping donor bone for custom fit as spacer implants for spinal fusions in the human spine as a replacement for one or more intervertebral discs in the cervical, thoracic or lumbar spines.
2. Discussion of the Prior Art
When intervertebral discs in the lumbar of humans become injured, degenerated, or diseased, a preferred treatment is to remove the damaged disc and implant in its place a spacer customly constructed from donor bone to facilitate bony fusion by bone growth between adjacent vertebra. Typically the damaged intervertebral disc is removed and bone graft material is packed in the intervertebral space. Such spinal fusions are becoming evermore commonly preformed and the trend is for the procedure to become more complicated involving more and more instrumentation and implants of various sorts and sizes to aide in the fusion construct. Spacer implants are pre-manufactured from donor bone and come in an extremely large variety of shapes and sizes and they are designed according to the vendor's philosophy, not the doctor's philosophy, regarding how the particular implant aides in the construct and fusion process. In addition, these pre-manufactured implants are becoming extremely expensive.
These pre-machined spacer implants are machined by the surgical supply vendors to exact dimensions and packaged according to size of the implant. At the time of surgery, the physician determines the size of the implant required to adequately fill the space to be fused, and a pair of appropriately sized implants are selected and opened. As a present day example, a one level lumbar fusion, utilizing posterior lumbar inter-body fusion implants (PLIF) costs approximately $4,000.00 U.S. Dollars for the PLIF implants alone. For each additional level which is fused, this cost is multiplied. For example a two level fusion implant costs $8,000.00. Over the last decade, greater financial restraints have been placed on hospitals, and subsequently on physicians performing these procedures and surgical implant vendors for lower cost options. Presently no such options are available. In addition, the surgeon has no input or choice in selecting the particular design of the spacer implant to provide a good custom fit.
Recently there has also been pressure to produce biologically conductive PLIF bony implants since the body will eventually assimilate the PLIF material and the PLIF implant does not interfere with follow-up radiographs as do metal implants. The implants need to be formed with exact precision and be exactly reproducible so that there will exist a well formed pair of PLIF implants. It is therefore an object of the present invention to permit the surgeon, himself or herself, to fabricate such donor bone implants quickly within the operating room to exact custom dimensions while the operative case is ongoing.

Bone cutting jig system for spinal implant


A wavelength correction function provides corrected reflectance values from actual reflectance values taken in a reflectance-base instrument. The correction is provided as a function of measured reflectance values and a predefined set of high resolution reflectance values established for the reflectance-based instrument implementing the wavelength correction function.

Reflectance-based instruments have long been in use in a variety of applications. One type of reflectance-based system is referred to as a "reflectometer", used to perform tests in certain medical and laboratory applications. In a typical form, a reflectometer includes one or more light sources configured to generate one or more light signals at given wavelengths. An object under test receives the signal and reflects a portion thereof—referred to as "reflectance". Reflectance is typically considered to be unit-less because it is defined as the ratio of the light actually leaving a sample to the amount that would leave if none were absorbed. In recent years, the National Institute of Standards and Technology (NIST) has defined reflectance in terms of this kind of mathematical model, rather than provide a physical reflectance standard. The perfect diffuse surface scatters light according to Lambert's law, which states that the intensity of light scattered from a point on a reflecting surface follows a cosine relationship with the polar angle of the scattered light, independent of the direction of the incident light. One or more detectors or sensors are oriented to receive the reflected signals. A processor analyzes the characteristics of the received reflected signals and produces a test result.
Such reflectometers are sometimes used for performing tests on a reagent test strip. In such a case, the test pads on the test strip may be incrementally tested to determine the presence of analytes in a liquid test sample absorbed into the test pads. Such systems may be used for performing urinalysis tests, as one example. That is, the level or presence of an analyte in a liquid test sample can be determined by causing a given test pad to absorb some of the liquid test sample, (e.g., a sample of urine) and then by reading associated reflectance values for the test pad with a reflectometer. Based on the spectral reflectance characteristics of the signal reflected by the test pad, the reflectometer determines the presence or level of the analyte in a given test pad. As an example, a test pad changes color to indicate the level or presence of the analyte in response to absorption of urine from a urine sample. The characteristics of a reflected signal are a function of the make-up and color of the test pad and the wavelength of the light source. Consequently, a change in color of a test pad causes a corresponding change in the characteristics of the reflected signal.
Test strips are typically produced according to industry accepted formats. In the case of urinalysis reflectometers, test strips can come in formats having different lengths, such as, for example, 3.25 inch lengths or 4.25 inch lengths. Within each format, a test strip is defmed according to its configuration, i.e., the number, types and order of test pads included on the test strip. Generally, each test strip configuration is uniquely identified., Implicit in a test strip identification and/or confirmation, therefore, is the test strip format and the test pad configuration. As will be appreciated by those skilled in the art, such test pads may include, for example, pH, ketone, nitrite, and glucose test pads. In order for the reflectometer to produce valid results, the test strip must be identified by format and configuration, so that the reflectometer has a proper context to evaluate the received reflected signals, or reflectance values derived therefrom. That is, a reflectometer needs to know that a received reflected signal is produced by, for example, a glucose test pad or a ketone test pad.
Reagent cassettes can also tested using a reflectometer, in a manner very similar to that used for the test strip. Such reagent cassettes include a test region that provides visual indications of test results, similar the test pads of the test strips. The test region can produce a series of lines that embody the test results.
There is a variety of known ways that the test strip is identified to or by the reflectometer. In some reflectometers, an operator enters data into the reflectometer that indicates the identification of the test strip from a look up table, or chooses the identification from a set of predefined options. The same can be done for reagent cassettes. The reflectometer is then ready to process the test strip or cassette.
In typical reflectance-based instruments, such as reflectometers, light emitting diodes (LEDs) serve as sources of light, the reflections of which are then detected and evaluated. Each LED is specified to have a center wavelength, within some range. Depending on the application, the range can be relatively narrow, e.g., ±3 nanometers (nm). Wavelengths outside of this range can result in instrument errors or incorrect clinical results. Since there is no way to correct for LEDs having center wavelengths outside the specified range, presently, instrument makers are reliant on the relatively expensive process of sorting through large volumes of LEDs to find those that are within the specified range. Otherwise, reflectance-based instruments using less precise LEDs would be error prone.