A mobile terminal circuit for transmitting radio frequency identification (RFID) data to an RFID reader. The mobile terminal circuit comprises an antenna for communication with the RFID reader; a memory portion for storing RFID data together with mobile terminal protocol data; a codec for encoding the RFID data into RFID codec data; a modulator connected to the codec, for modulating the RFID codec data into RFID modulation data; a processor connected to the memory portion, for extracting RFID data stored in the memory portion and delivering the extracted RFID data to the codec; a detector connected to the antenna and the processor, for informing the processor of approach of the RFID reader; a first clock generator connected to the processor and the memory portion, for providing operation timing to the processor and the memory portion; and a second clock generator connected to the first clock generator, the codec and the modulator, for providing operation timing to the codec and the modulator.

1. Field of the Invention
The present invention relates generally to a radio frequency identification (RFID) tag, which is increasing in frequency of use and importance, and a widely-spread mobile terminal, and in particular, to a mobile terminal circuit including an RFID tag in one body and a wireless identification method using the same.
2. Description of the Related Art
An RFID transponder, or an RFID tag, was developed by United States National Laboratory for Department of Agriculture for the purpose of identifying livestock. An electric code for identifying an animal is recorded in a RFID tag, and then inserted into or attached to the animal. An interrogator (or a reader) for reading the electric code is installed in a cattle shed to conveniently monitor whether an animal has returned. The reader transmits an RF (Radio Frequency) signal to the RFID tag, and then, an electric code recorded in the RFID tag is delivered to the reader after being modulated by a modulator in the RFID tag. This procedure is called "backscatter modulation." The RFID tag has an antenna coil to transmit the modulated signal to the reader therethrough. An early such system is well disclosed in U.S. Pat. Nos. 4,075,632 and 4,360,810.
Over time, technology for identifying a moving object has been applied to additional fields other than cattle management. For example, such technology has been applied to a vehicle, a container vessel, a railcar, etc., and information recorded in an RFID tag of such transportation means is used in tracking a position of the transportation means and identifying the contents of freight. Such applications and related arts are well disclosed in U.S. Pat. Nos. 4,739,328, 4,782,345, 4,786,907, 4,816,839, 4,835,377, and 4,853,705.
Recently, RFID technology is tested in various fields, and among the various fields, a communication system has attracted public attention due to its various possible applications. For example, since a mobile communication system holds a great number of subscribers, it can easily make profits by commercializing an application service based on the RFID technology. Currently, a mobile communication system has been saturated in terms of an earning rate, so service providers are eagerly searching for new application services capable of creating additional profits.
If RFID technology is introduced into the mobile communication system, it is expected that various additional services for a cellular environment can be provided. Accordingly, it is most urgently necessary to combine current RFID devices to a current cellular system.
Related prior art is disclosed in WO 01/39103 A1, WO 03/025834 A1, an IEEE paper entitled "RF Rendez-Blue: Reducing Power And Inquiry Costs In Bluetooth-Enabled Mobile Systems," (E. S. Hall, D. K. Vawdrey, and C. D. Knutson, in Proc. 11th IEEE Int. Conf. Comput. Communications and Networks (ICCCN), Miami, Fla., October 2002.) and Korean Patent Publication No. 2002-0090929.
WO 01/39103 A1 discloses a mobile terminal in which an identification (ID) module is added between an RF block and an antenna, and the mobile terminal includes a Bluetooth module. The ID module includes a mixer, and the mixer converts a backscatter type message transmitted from the ID module to a reader at an RFID frequency of 2.45 GHz into a baseband message before transmission so that it can be processed in a computer, or transmits the backscatter type message to a base station over a traffic channel specified by a mobile communication standard or a Bluetooth channel. This technology is characterized by connecting an independent ID module to an existing mobile terminal circuit via a mixer. Through this, a base frequency band, i.e., an exiting traffic channel or Bluetooth channel, is used as an RFID frequency band. Therefore, a combination between heterogeneous circuits is not described herein.
WO 03/025834 A1 discloses a mobile terminal combined with an RFID reader, in which information is transmitted and received over a frequency band of the mobile terminal. However, the reference does not mention that instead of the RFID reader, an RFID tag can be combined with the mobile terminal. In addition, since combination between the RFID reader circuit and the terminal circuit is not disclosed, one skilled in the art cannot predict a combination of the RFID tag circuit and the terminal circuit in the light of the connection between the RFID reader circuit and the terminal circuit.
The IEEE paper discloses a structure for connecting an RFID module to a Bluetooth module in parallel in order to reduce an initial processing time of the Bluetooth module, and this is very different from a single-body type structure proposed by the present invention.
Korean Patent Publication No. 2002-0090929 discloses technology in which an independent smart card sends data to a main processing unit (MPU) of a mobile terminal. However, the reference fails to propose the connection between the smart card and the MPU or its peripheral circuit. That is, it is nothing more than simply arranging an independent circuit and a processor in one device.
The above references mainly disclose parallel connection between an RFID module or tag and a terminal circuit, or propose resource sharing in terms of frequency. However, the conventional technologies have the following disadvantages.
First, it is difficult to achieve miniaturization of a mobile terminal. Although an RFID tag can be implemented through combination of one chip with an antenna coil, it must be implemented in a smaller size to meet a general tendency toward miniaturization of the mobile terminal.
Second, since the conventional RFID tag does not have its own power supply, electromotive force induced from a carrier of an RFID reader is used as electric power. In this case, it is difficult to provide sufficient electric power to the RFID tag in an environment where an air environment between the RFID reader and the RFID tag is influenced by noises. |As a result, the RFID tag may operate incorrectly.

Mobile terminal circuit including an RFID tag and wireless identification method using the same


A multipurpose pillow assembly (10) for supporting lamaze partners, including a coach (C) and a pregnant woman (W), during lamaze exercises and for supporting a newborn (N) while a care-giver (G) is feeding the newborn (N) is disclosed. The pillow assembly (10) includes a body pillow (12), an attachable seat pillow (14) removably coupled to the body pillow (12), and a normally unattached seat pillow (16). The attachable seat pillow (14) is removably coupled to the body pillow (12) by a pair of stretchable straps (28),(30).

1. Field of the Invention
The present invention relates generally to support devices used when conducting activities associated with childbirth. More specifically, the present invention concerns a multipurpose pillow assembly usable for activities such as supporting lamaze partners, including a coach and a pregnant woman, during lamaze exercises and for supporting a newborn during feeding.
2. Discussion of Prior Art
When a care-giver is bottle-feeding or breast-feeding a newborn baby, it is desirable to support the weight of the infant as well as the arms of the care-giver. Prior art pillows have been developed for this purpose; however, these prior art pillows are problematic and have several limitations. For example, prior art pillows do not provide desired support for the care-giver""s back or buttocks during feedings. Prior art pillows also do not securely attach to the care-giver therefore making it difficult for the care-giver to change positions while keeping both hands on the infant.
Lamaze exercises are designed to facilitate relaxation of a pregnant woman during various stages of labor associated with natural childbirth and typically require the participation of a lamaze partner to assist and coach the woman. Several of these exercises involve both partners seated on the floor with the coach applying pressure to the woman""s lower back in an effort to relieve tension and pain therein. Some of the stages of labor can last several hours. It is therefore desirable to cushion and support both lamaze partners while seated on the floor and to facilitate applying pressure to the woman""s lower back in a hands-free manner so that the coach""s hands are free to target other portions of the woman""s body during a prolonged and painful stage of labor. Prior art pillows that were not specifically designed for these purposes have been implemented; however, use of these pillows is problematic and the prior art pillows have several limitations. For example, prior art pillows do not provide support for the woman""s buttocks that is secure from undesirable slippage and movement. Prior art pillows also do not securely attach to a lamaze partner therefore making it difficult for the partners to utilize any hands-free pressure applications or to quickly and easily change positions.
Known prior art pillows are further limited in that they are not useful for both supporting a newborn during feeding and for supporting lamaze partners during lamaze exercises. For example, prior art pillows are not versatile in that the support they provide is limited to one or two activities (e.g., prior art nursing pillows may support the newborn but they cannot simultaneously support the care-giver""s back and/or buttocks). Similarly, prior art pillows that may support the lamaze partners"" buttocks cannot simultaneously facilitate pressure application to one of the partner""s back.
The present invention provides an improved multipurpose pillow assembly that does not suffer from the problems and limitations of prior art pillows set forth above. A first aspect of the inventive pillow assembly concerns a multipurpose pillow assembly that broadly includes a generally U-shaped body pillow adapted to extend at least partly around the midriff of a user, and a seat pillow removably coupled to the body pillow and attached thereto in a manner that enables the user to sit upon the seat pillow when the body pillow is at least partly around the midriff of the user.
A second aspect of the inventive pillow assembly involves a seat pillow that broadly includes a generally elliptically shaped cushion having a central opening and adapted to be sat upon by a user wherein the central opening is adjacent the user""s perineal area when the user is sitting on the cushion, a cover substantially containing the cushion, and at least one stretchable strap coupled to the cover and operable to removably secure the cushion-filled cover relative to the user.
A third aspect of the inventive pillow assembly concerns a multipurpose pillow assembly for supporting lamaze partners, including a coach and a pregnant woman, during lamaze exercises and for supporting a newborn during feeding, and broadly includes an enclosable body pillow adjustable between a pregnancy position, wherein the body pillow is adapted to encircle the midriff of one of the lamaze partners, and a feeding position, wherein the body pillow is adapted to support the feeding newborn; and at least one seat pillow adapted to be sat upon by either lamaze partner when the body pillow is in the pregnancy position, said at least one seat pillow being removably coupled to the body pillow.
Other aspects and advantages of the present invention will be apparent from the following detailed description of the preferred embodiments and the accompanying drawing figures.


An improved system for transmitting and receiving spread spectrum signals includes a transmitter and a receiver, each with a data channel and a control channel. The transmitter uses two pseudorandom noise sequences (PNS), one whose period is equal to that of a coded data bit ("bit PNS"), the other whose period is equal to that of a codeword ("word PNS"). The data channel is modulated by a carrier signal and spread by the bit PNS. The control channel is modulated by a quadrature-phase version of the carrier signal and spread by the word PNS. The control channel sends instructions to the PNS generators to change the forms of the PN sequences in the transmitter. The receiver includes a control channel tracking and acquisition (T&A) and carrier restoration module and a data channel T&A module. The control channel T&A uses a stored version of the word PNS and outputs a word synchronization signal, a phased version of the word PNS, a quadrature-phase carrier signal, and an in-phase carrier signal. The receiver control channel recovers the control signals and uses them to change the forms of the PN sequences in the receiver. The data channel T&A uses a stored version of the bit PNS to despread the received signal. The data channel T&A also outputs a bit synchronization signal used in decision-making and decoding the demodulated received signal. By using the two PNS generators, this system eliminates the need for separate clock frequency extraction hardware and frame or word synchronization hardware, improving receiver throughput, simplifying the receiver, and making it less expensive. By changing the PNS forms, the system operates with a wider effective bandwidth resulting in increased processing gain, noise immunity, interference rejection, and channel capacity.

1. Field of the Invention
The present invention relates to broadband communication systems and particularly to systems for transmission and reception of pseudorandom noise and spread spectrum signals, and to code division multiple access systems with application to satellite and terrestrial communications.
2. Description of the Related Art
Spread spectrum systems have been used for many years in digital communications. A spread spectrum signal consists of a baseband message signal modulated onto a carrier and thereafter spread in frequency by a pseudorandom noise sequence ("PN sequence" or "PNS"), independent of the message signal itself. The receiver then recovers the message signal by using a replica of the PN sequence. The main advantages of spread spectrum systems are good interference and noise rejection, low power density, ability to access multiple channels (such as in code division multiple access (CDMA) systems), high resolution ranging, and message protection. The ratio of the bandwidth of the PNS to that of the message signal, called the processing gain, determines the merit of the system.
Typical block diagrams of a spread spectrum transmitter and receiver are found in J. K. Holmes, Coherent Spread Spectrum Systems (Wiley 1982), and reproduced as FIGS. 1a and 1b. In the transmitter in FIG. 1a, a digital message signal transmitted at bit rate B is provided to coder 100. This coder encodes the data bits into codewords for transmission and can be a block coder or a convolutional coder as described in G. C. Clark and J. B. Cain, Error-Correction Coding for Digital Communications (Plenum Press 1981). Carrier frequency generator 112 generates a carrier frequency signal that is modulated by the coded signal in carrier modulator 106. PNS modulator 108 then further modulates (or spreads) the modulated carrier signal with a PN sequence from PNS generator 128. The PNS is a digital signal made up of "chips" and whose chip interval or chip period is much smaller than the data bit period (thus the bandwidth of the PN sequence is much greater than that of the data signal). The resulting signal is amplified by amplifier 130 and transmitted by antenna 140.
As depicted in FIG. 1b, the transmitted signal is received by antenna 152 and amplified by amplifier 154. Because the phase and frequency of the received signal is unknown, the received signal must be acquired and tracked to establish phase synchronization. The received signal is provided to tracking and acquisition (T&A) synchronism device 164 which contains a PNS generator that generates a replica of the PNS that was used in the transmitter. In the acquisition stage, a coarse alignment between the replicated PNS and the received signal is performed using serial and/or sequential search, sequential estimation, universal timing, or matched filter algorithms. These techniques are described in various references, one of which is R. C. Dixon, Spread Spectrum Systems with Commercial Applications (Wiley 1994). The acquisition stage brings the replicated PNS and the received signal within half a chip interval of each other. Once the received signal is acquired, the two signals are tracked, generally using a delay-lock loop. See, e.g., J. J. Spilker, Digital Communications by Satellite (Prentice Hall 1977). Once synchronized, T&A synchronism device 164 outputs the in-phase PNS to PNS demodulator 156 which demodulates (despreads) the received signal. The despread signal is provided to carrier restoration and phasing module 166 which provides a local oscillator signal which is phase-synchronized to the carrier signal. The local oscillator signal is used to demodulate the despread signal in coherent detector 158 producing a baseband coded data signal. The baseband signal is provided to clock frequency extractor 168 to extract the clock signal, which in turn is provided to decision circuit 160 which can be implemented as an integrator over a bit period to determine whether a code bit is a one or a zero. Decision circuit 160 provides squared-up digital data code bits to frame synchronization device 170 and noise-immune decoder 162. Frame synchronization device 170 uses the clock signal from clock frequency extractor 168 to extract the word (or frame) timing from the digital data code bits to derive a frame synchronization signal that is used to decode the digital data signal in noise-immune decoder 162 to recover the original digital message signal.
The main problem associated with this spread spectrum system is that the receiver contains a sequence of modules--tracking and acquisition 164, carrier restoration 166, clock extraction 168, and frame synchronization 170--each of which must wait for the previous module to acquire synchronization before being able to start its own synchronization process. The throughput of the system is therefore dependent upon each of the modules and can suffer if only one is slow to synchronize. Another problem is that the receiver requires four separate modules that duplicate some functions, i.e. phasing is performed in T&A synchronism device 164 and in carrier restoration and phasing module 166, and clock frequency extractor 168 is needed because the phasing performed by T&A synchronism device 164 is not accurate enough to clock decision circuit 160.
An improved prior art system is depicted in FIGS. 2a and 2b. In the transmitter in FIG. 2a, coder 204, carrier modulator 206, PNS modulator 208, carrier frequency generator 212, amplifier 230, and antenna 240 perform as in FIG. 1a. New to this transmitter is a second output from PNS generator 228 that provides a pulse corresponding to the beginning of each period of the PNS to switch 222 and period multiplier 210. Switch 222 then provides a clock to buffer memory 202 to synchronously clock the data bits into coder 204. The multiplication factor in period multiplier 210 is variable; thus, the period of the data bits clocked through to coder 204 can vary but is always an integral multiple of the PNS period. The use of this relationship between the data bit period and the PNS period enables the system to eliminate the clock frequency extractor from the receiver in FIG. 2b. In its place are switch 268 and period multiplier 272 which detect the clock, but do so at an earlier stage than in FIG. 1b because period multiplier 272 is directly connected to T&A synchronism device 264. The rest of the receiver works as before; thus, when the baseband coded data signal reaches decision circuit 260 from coherent detector 258, clock synchronization has already been performed and only frame synchronization remains to be performed.
One advantage of this system over the prior art system in FIGS. 1a and 1b is that the circuitry is simpler because the clock frequency extractor is more complex than the switches and multipliers in the transmitter and receiver that substitute for the clock frequency extractor. Another advantage is that the receiver operates more quickly because clock synchronization is performed simultaneously with carrier restoration.
However, there are still problems with this spread spectrum system. First, the bulk of the receiver still operates serially, reducing receiver throughput. Second, the frame synchronization device takes time to generate a frame synchronization signal and has low noise immunity due to the possibility of elementary signal distortion inside the frame synchronization signal, especially when communicating with moving objects. There may also be false start-ups in frame synchronization device 270 when there is low redundancy in the frame synchronization signal. Third, the operation of this type of system is limited when the PNS period is on the order of several chips, because the discrete nature of the spectrum radiated by the transmitter decreases the bandwidth of the system, lowering channel capacity when operating in code division mode and reducing noise immunity and interference rejection. These drawbacks may be lessened by lengthening the PNS period, which creates a more continuous spectrum, but that significantly complicates the receiving equipment, lengthens acquisition and tracking time, and worsens correlation functions in the receiver. This lowers the effective signal base which in turn reduces channel capacity and interference rejection.
The present invention addresses the shortcomings in these prior art systems. Thus, it is an object of the present invention to provide a spread spectrum system with better noise immunity, faster receiver synchronization, simpler electronics, and increased channel capacity and interference rejection.

System for discrete data transmission with noise-like, broadband signals


A multiple quantum well (MQW) radiation sensor distinguishes radiation within a desired bandwidth, particularly long wavelength infrared radiation (LWIR), from background high intensity noise radiation that excites majority-minority charge carrier pairs. A minority charge carrier collector is provided at one end of the MQW, and the flow of minority charge carriers to the collector is sensed. The minority charge carrier flow provides an indication of the majority charge carrier flow that is attributable to the noise radiation rather than to radiation within the desired bandwidth, and can thus be used to provide a corrected indication of the desired bandwidth radiation.

1. Field of the Invention
This invention relates to the detector of electromagnetic radiation with a multiple quantum well (MQW) super-lattice structure, and more particularly to the sensing of long wavelength infrared radiation (LWIR) in the presence of background radiation from intrinsic events.
2. Description of the Related Art
The detection of LWIR with an MQW sensor has been reported in several publications: Levine et al., "Bound-to-Extended State Absorption GaAs Superlattice Transport Infrared Detectors", J. Applied Physics Letters Vol. 64, No. 3, 1 Aug. 1988, pages 1591-1593; Levine et al., "Broad-band 8-12 .mu.m High-Sensitivity GaAs Quantum Well Infrared Photodetector", Applied Physics Letters Vol. 54, No. 26, 26 June 1989, pages 2704-2706; Hasnain et al., "GaAs/AlGaAs Multiquantum Well Infrared Detector Arrays Using Etched Gratings", Applied Physics Letters Vol. 54, No. 25, 19 June 1989, pages 2515-2517; Levine et al., "High-Detectivity D*=1.O.times.10.sup.10 cm .sqroot./W GaAs/AlGaAs Multiquantum Well .lambda.=8.3 .mu.m Infrared Detector", Applied Physics Letters, Vol. 53, No. 4, 25 July 1988, pages 296-298.
The detector consists of a periodic heterostructure of GaAs quantum wells and AlGaAs barrier layers. The GaAs quantum well layers are doped with an n-type dopant such as silicon to provide electrons in the ground states of the wells for intersubband detection. Lacking an internal built-in electric field, the device operates as a photoconductive sensor. Under the influence of a bias voltage applied across n-doped contact layers at opposite ends of the MQW structure, electrons excited into a conduction band above the barrier heights flow through the device for collection at one of the contact layers. This majority current flow is sensed by an external ammeter and provides an indication of the amount of LWIR that is incident upon the device.
An improvement upon this detector is disclosed in pending U.S. patent application Ser. No. 07/457,613 filed Dec. 27, 1989 by Sato et al., "Dark Current-Free Multi-quantum Well Superlattice Infrared Detector", and assigned to Hughes Aircraft Company, the assignee of the present invention. In this improvement a blocking layer of barrier material is provided between the MQW superlattice and the collector contact. The blocking layer is substantially thicker than the barrier layers, thus eliminating most of the tunneling current component of the photodetector's dark current. This in turn allows the individual blocking layers to be made thinner, thus enhancing the detector's quantum efficiency.
Although the Sato et al. device improves upon the other detectors referenced above, all of these devices suffer from the presence of background noise signals caused by incident high energy photons or particles (collectively referred to hereinafter as radiation) from intrinsic events such as laser light, nuclear explosions and cosmic rays. Such intrinsic event radiation adds to the total majority carrier flow in the detector, resulting in spurious signals that can severely hamper the operation of the detector array, particularly in space-borne environments.

Apparatus and method for discriminating against undesired radiation in a multiple quantum well long wavelength infrared detector


An improved process for recycling unspent diol removed from a polyester manufacturing process wherein the diol is captured, hydrogenated, and recycled so that the final polyester product has improved color over polyesters produced using other recycled diols.

Polyesters such as, for example, polyethylene terephthalate and polybutylene terephthalate, generally referred to as "polyalkene terephthalates", are a class of important industrial polymers. They are widely used in thermoplastic fibers, films, and molding applications. Generally, polyesters are produced by reaction of a diol with a dicarboxylic acid or a lower alkyl ester of a dicarboxylic acid, e.g., the dimethyl ester. At first, the corresponding dicarboxylic acid diester is formed. Next, the dicarboxylic acid diester is polycondensed at increasing temperature and reduced pressure. Both reaction steps can be accelerated by catalysts. Compounds of titanium (Ti), manganese (Mn), cobalt (Co) or zinc (Zn) are suitable for the transesterification, and compounds of antimony (Sb), titanium (Ti), lead (Pb), germanium (Ge), zinc (Zn) or tin (Sn) for the polycondensation, whereby the catalyst compounds are in general oxides, alcoholates, acetates, or carboxylates. The amount of metal ion in the catalyst compound ranges mostly between 20 and 500 ppm, based on polyester. Among these catalysts, the titanium compounds are considered the most effective and the most widely usable because they are non-poisonous and can be used in the esterification or transesterification reactions, as well as in the polycondensation reaction.
However, these catalysts often react with trace quantities of aldehyde-based impurities derived from the diol and produced in the polymerization process, which causes the resulting polymer to develop a more yellow color. Diol recovered from the manufacturing process contains increased amounts of these impurities, which are believed to include aldehydes and their condensation products. Because polyester manufacturers return the recovered diol back into the manufacturing process to decrease manufacturing costs, the yellowing phenomenon increases as more and more impurities from the recovered diol accumulate and impact the polyester production. U.S. Pat. No. 4,110,316 describes such a polyester manufacturing process that recovers diol from the polymerization vessels for reuse in the process.
Increased yellowing of the polyester limits the subsequent downstream uses of the polyester. For example, many end-use applications require polyester sheets to be as clear (non-yellow) as possible.
There have been several attempts to improve the color of polyester. WO 02/18471 discloses a process for purifying a polyester precursor wherein a polyester oligomer derived from terephthalic acid and one or more diols is decolorized by hydrogenating the oligomer.
The non-examined Japanese patent application, Kokai No. SHO 51[1976]-1403, discloses a method for purifying crude ethylene glycol by first distilling the ethylene glycol followed by hydrogenation.
The examined Japanese patent application, Kokoku No. HEI 4[1992]-28247, discloses a method for purifying crude ethylene glycol formed in the preparation of ethylene oxide. This method includes distilling the crude glycol, hydrogenating the crude distilled glycol, and then purifying the resulting glycol by, for example, vacuum distillation.
As shown in these previous disclosures, removing color-forming impurities from a glycol (diol) stream has been accomplished in multiple steps. While one of the steps may be hydrogenation, at least one other purifying step, such as distillation, has been required to achieve the desired result.
Therefore, it is desired to have a process for removing impurities from recovered diol before the diol is recycled to the beginning of a polyester manufacturing process, whereby the recovered diol is effective in producing a polyester polymer product with improved color (e.g., reduced yellowing as compared with processes where the diol impurities are not removed, or are not removed as effectively as the invention described herein).
It is also desired to produce polyester while recycling the recovered diol, such that the polyester has good color properties.
It is also desired to provide a process for producing polyester from inferior grades of starting materials (diols, dicarboxylic acids and lower alkyl esters of dicarboxylic acids) without adversely impacting the color properties of the resulting polyester.

Process for the manufacture of polyester via hydrogenation treatment of recycled diol


Apparatus and methods for calibration of envelope trackers are provided. In one embodiment, a power amplifier system includes a VGA that amplifies an RF input signal to generate an amplified RF input signal, a power amplifier that amplifies the amplified RF input signal to generate an RF output signal, and an envelope tracker that generates a supply voltage for the power amplifier. The envelope tracker includes a scaling module that generates a scaled envelope signal based on a power control level (PCL) signal and an envelope signal that changes in relation to an envelope of the RF input signal. The envelope tracker further includes a calibration module that controls an amount of scaling of the scaled envelope signal based on calibration data to compensate for an envelope amplitude misalignment of the envelope tracker. The envelope tracker controls the voltage level of the supply voltage based on the scaled envelope signal.

Field
Embodiments of the invention relate to electronic systems, and in particular, to radio frequency (RF) electronics.
Description of the Related Technology
Power amplifiers can be included in mobile phones to amplify a RF signal for transmission. For example, in mobile phones having a time division multiple access (TDMA) architecture, such as those found in Global System for Mobile Communications (GSM), code division multiple access (CDMA), and wideband code division multiple access (W-CDMA) systems, a power amplifier can be used to amplify a RF signal for transmission via an antenna. It can be important manage the amplification of a RF signal, as a desired transmitted power level can depend on how far the user is away from a base station and/or the mobile environment. Power amplifiers can also be employed to aid in regulating the power level of the RF signal over time, so as to prevent signal interference from transmission during an assigned receive time slot.
The power efficiency of a power amplifier at a particular input power level can be a function of a variety of factors, including circuit component and layout, power amplifier load, and/or power amplifier supply voltage. To aid in improving the efficiency of a power amplifier, a technique known as envelope tracking can be used, in which the voltage level of the power supply of the power amplifier is changed in relation to the envelope of the RF signal. Thus, when the envelope of the RF signal increases, the voltage supplied to the power amplifier can be increased. Likewise, when the envelope of the RF signal decreases, the voltage supplied to the power amplifier can be decreased to reduce power consumption.

This patent is subject to a terminal disclaimer.


A telecommunications node (28) comprises a communication interface (36) and a parameter controller (40). The node (28) acquires timing advance (TA) information and angle of arrival (AoA) information through the communication interface (36). The timing advance (TA) information and angle of arrival (AoA) information are based on uplink signals received over a radio interface (32) from one or more wireless terminals (30) that are involved or have been involved in handover. The parameter controller (40) uses the timing advance (TA) information and the angle of arrival (AoA) information to make a determination of size and shape of a cell of a radio access network.

1.0 Mobile Communication Systems
In a typical cellular radio system, wireless terminals, also known as mobile stations and/or user equipments (UEs), communicate via a radio access network (RAN) to one or more core networks. The radio access network covers a geographical area which is divided into cell areas, with each cell area being served by a base station, e.g., a radio base station (RBS), which in some networks may also be called, for example, a "NodeB" (UMTS) or "eNodeB" (LTE). A cell is a geographical area where radio coverage is provided by the radio base station equipment at a base station site. Each cell is identified by an identity within the local radio area, which is broadcast in the cell. Another identity identifying the cell uniquely in the whole mobile network is also broadcasted in the cell. The base stations communicate over the air interface operating on radio frequencies with the user equipment units (UE) within range of the base stations.
In some versions of the radio access network, several base stations are typically connected, e.g., by landlines or microwave, to a controller node, such as a radio network controller (RNC) or a base station controller (BSC), which supervises and coordinates various activities of the plural base stations connected thereto. The radio network controllers are typically connected to one or more core networks.
The Universal Mobile Telecommunications System (UMTS) is a third generation mobile communication system, which evolved from the second generation (2G) Global System for Mobile Communications (GSM). The UMTS terrestrial radio access network (UTRAN) is essentially a radio access network using wideband code division multiple access for user equipment units (UEs). In a forum known as the Third Generation Partnership Project (3GPP), telecommunications suppliers propose and agree upon standards for third generation networks and UTRAN specifically, and investigate enhanced data rate and radio capacity. Specifications for the Evolved Packet System (EPS) have completed within the 3rd Generation Partnership Project (3GPP) and this work continues in the coming 3GPP releases. The EPS comprises the Evolved Universal Terrestrial Radio Access Network (E-UTRAN), also known as the Long Term Evolution (LTE) radio access, and the Evolved Packet Core (EPC), also known as System Architecture Evolution (SAE) core network. E-UTRAN/LTE is a variant of a 3GPP radio access technology wherein the radio base station nodes are directly connected to the EPC core network rather than to radio network controller (RNC) nodes. In general, in E-UTRAN/LTE the functions of a radio network controller (RNC) node are distributed between the radio base stations nodes, e.g., eNodeBs in LTE, and the core network. As such, the radio access network (RAN) of an EPS system has an essentially "flat" architecture comprising radio base station nodes without reporting to radio network controller (RNC) nodes.
1.1 Heterogeneous Networks
There have been several proposals to meet the ever increasing traffic demands and high quality expectations from end users for mobile broadband services. The upgrading of the existing base stations to use higher data rate technologies such as High Speed Packet Access (HSPA) or Long Term Evolution (LTE), or use other optimizations such as Multiple Input Multiple Output (MIMO), antenna tilting, etc., is one of the most widely adopted means to meet these demands. This can be further enhanced by a straightforward increasing the number of base stations (eNBs) in the network, known as macro densification. However, these methods of improving the data rate can provide system gains only to a certain extent and they can end up being very expensive. As such, the concept of Heterogeneous Networks (HetNets), where the existing homogeneous network is overlaid with additional lower-power, low-complexity base stations, is currently being researched as a solution to mitigate the cost and/or capacity limitations of macro densification or upgrading.
The homogeneous layer of macro cells is known as a "macro" layer, as the eNBs in this layer have large coverage areas. The non-homogenous layer contains low power nodes such as "picos" (low power eNBs, for indoor or outdoor usage), "femtos" (home base stations (HeNBs), usually for indoor home usage) or relays (usually for coverage extension). Femtos that are open only to few users (within a household, a shop, etc.), are termed within 3GPP as Closed Subscriber Group (CSG). FIG. 1 illustrates an example HetNet deployment scenario.
HetNets are expected to offer a low cost alternative to macro densification and will more likely be effective as the deployment of the low power nodes can be made more focused towards the hot spots and areas with coverage problems. The term "small cell" is used to refer to a pico or a femto cell for the rest of this document.
1.2 Handover in LTE
Handover is one of the important aspects of any mobile communication system, where the system tries to assure service continuity of the User Equipment (UE) by transferring the connection from one cell to another depending on several factors such as signal strength, load conditions, service requirements, etc. The provision of efficient/effective handovers (minimum number of unnecessary handovers, minimum number of handover failures, minimum handover delay, etc.), would affect not only the Quality of Service (QoS) of the end user but also the overall mobile network capacity and performance.
In LTE, UE-assisted, network controlled handover is utilized. The network configures the UE to perform measurements and send measurement reports when certain criteria are met. Based on these reports the UE is moved, if required and possible, to the most appropriate cell that will assure service continuity and quality. A UE measurement report configuration comprises the reporting criteria (whether it is periodic or event triggered) as well as the measurement information that the UE has to report.
In LTE, the most important measurements metric used are the Reference Signal Received Power (RSRP) and Reference Signal Received Quality (RSRQ). RSRP is a cell specific measure of signal strength and it is mainly used for ranking different cells for handover and cell reselection purposes, and it is calculated as the linear average of the power of the Resource Elements (REs) which carry cell-specific Reference Symbols (RSs). The RSRQ, on the other hand, also takes the interference into consideration by taking the total received wideband power into account as well.
One of the configuration parameters that UEs receive from their serving eNB is a parameter called "S_measure", which tells the UE when to start measuring neighboring cells. If the measured RSRP of the serving cell falls below the S_measure, indicating the signal of the serving cell is not that strong anymore, the UE starts measuring the signal strength of RSs from the neighboring cells.
While the S_measure determines when the UE starts measuring other cells, there are several other measurement configuration parameters that specify the triggering of handover measurement reports from the UE. The following event-triggered criteria are specified for intra-Radio Access Technology (RAT) measurement reporting in LTE:                Event A1: Serving cell becomes better than absolute threshold.        Event A2: Serving cell becomes worse than absolute threshold.        Event A3: Neighbor cell becomes better than an offset relative to the serving cell.        Event A4: Neighbor cell becomes better than absolute threshold.        Event A5: Serving cell becomes worse than one absolute threshold and neighbor cell becomes better than another absolute threshold.
The most common measurement report triggering event related to handover is A3; its usage is illustrated in FIG. 2. The triggering conditions for event A3 can be formulated as Expression (1):N>S+(Hs−CIOs,n)  Expression (1)where N and S are the signal strengths of the neighbor and serving cells, respectively, Hs is the hysteresis parameter that the serving cell applies for event A3, and CIOs,n is the Cell Individual Offset (CIO) set by the serving cell for that specific neighbor cell. If this condition is satisfied and it remains valid for a certain duration known as Time To Trigger (TTT), the UE sends a measurement report to the serving eNB (in FIG. 2, entry condition for event A3 is satisfied at point A and measurement report is sent at point B in time when both entry condition and TTT criteria are fulfilled, i.e., the event criteria is fulfilled). When the serving eNB gets the measurement report, it may initiate a handover towards a neighbor.
1.3 Mobility Robustness Optimization
As indicated above, handover in LTE is controlled via several parameters. Incorrect parameter settings can lead to several problems, such as (for example) Radio Link Failure (RLF) and Ping pong handover.
If the parameters are set in such a way that the UE does not report handover measurements on time and the UE loses the radio connection with the serving cell, the UE experiences a Radio Link Failure (RLF) before handover could be initiated. This is known as "Too Late HO" and the UE tries to re-establish the connection with another cell after the RLF detection timers have expired. On the other hand, if the parameters are set to trigger handover very early, RLF might occur shortly after handover preparation has been completed and the UE has either completed or it is in the process of completing it in the target cell. This is known as "Too Early HO" and the UE tries to re-establish the connection with the source cell after the RLF detection timers have expired. Even if the handover is triggered at the right time, incorrect settings of the CIO can make the UE to handover to the wrong cell, which is followed by a RLF and a re-establishment request in a cell other than the target cell or the source cell. This is known as "HO to a wrong cell".
Improper handover parameter setting can make the UE handover back and forth between two neighboring cells, e.g., "Ping pong handover". An example of this is a setting that makes the triggering conditions for the handover events (A3) valid between the source and neighbor cells at the same time.
When the UE receives a certain number of (N310) consecutive "out of sync" indications from the lower layer, it assumes a physical layer problem is ensuing, and a timer (T310) is started. If the UE does not receive a certain number of (N311) consecutive "in sync" indications from the lower layer before T310 expires, RLF is detected. RLF is also detected when random access problem is indicated from MAC or upon indication that the maximum number of RLC retransmissions has been reached.
Another type of failure is a HO failure (HOF). When the UE receives a HO command (i.e., RRCConnectionReconfigurationRequest with mobilityControlInfo), it starts a timer (T304), and if this timer expires before the HO is completed (i.e., RRCConnectionReconfigurationComplete message is sent by the UE), a HO failure is detected.
The less the number of RLFs and HOFs in the system, the better the performance, both from user and system perspective. As such, it is very desirable to configure the system parameters (the HO parameters discussed above being the main ones) appropriately.
Configuring all the HO parameters manually is too expensive and can be very challenging. As such, Mobility Robustness Optimization (MRO) has been introduced in 3GPP to automate the dynamic configuration of handover parameters. MRO tries to gather statistics on the occurrence of Too Late HOs, Too Early HOs and HO to the wrong cell, and these statistics are used to adjust the handover parameters such as Hysteresis, CIO and TTT.
For MRO, the different HO problems discussed above are communicated between neighboring cells in different ways. For Too Late Handovers, an RLF INDICATION message is sent via X2 from the eNB to which the UE tries to re-establish a connection to the eNB where the RLF occurred. The RLF INDICATION message contains:                PCI of the cell in which the UE was connected prior to RLF (known as failure cell).        ECGI of the cell where RRC re-establishment attempt was made.        UE Identity: C-RNTI and MAC ID of the UE in the failure cell        RLF report (in a UE RLF Report Container IE
If an eNB receives an RLF INDICATION message from a neighbor eNB, and if it finds out that it has sent a UE CONTEXT RELEASE message towards that neighbor eNB within the last Tstore_UE_cntxt seconds (i.e., it means that very recently the concerned UE was handed over properly to it from the same eNB), the eNB responds by sending a HANDOVER REPORT message that indicates Too Early Handover.
If an eNB receives an RLF INDICATION message from a neighbor eNB, and if it finds out that it has sent a UE CONTEXT RELEASE message towards another neighbor eNB within the last Tstore_UE_cntxt seconds (i.e., it means that very recently the concerned UE was handed over properly to it from another eNB), the eNB responds by sending a HANDOVER REPORT message that indicates Handover to the Wrong Cell.
The HANDOVER REPORT message contains:                Type of detected handover problem (Too Early Handover, Handover to Wrong Cell);        ECGI of source and target cells in the handover;        ECGI of the re-establishment cell (in the case of Handover to Wrong Cell);        Handover cause (signaled by the source during handover preparation).
Thus, by analyzing the received RLF INDICATION and HANDOVER REPORT messages within certain duration, eNBs can configure the optimal HO parameters to be used with their neighbors.
1.4 Enhanced Mobility Robustness Optimization
As mentioned above, current mechanisms such as Mobility Robustness Optimization (MRO) try to optimize mobility by fine tuning of mobility thresholds such as CIOs with the objective of preventing further failures from occurring.
Though the standardized MRO mechanisms can be very useful, they have limitations, specifically in HetNet scenarios because the cells involved in mobility are a mixture of large coverage layer cells and small hot spot coverage cells aimed at increasing capacity in a much localized way. Hence, the success of UE mobility in a HetNet scenario greatly depends on the time the UE is expected to spend on a given cell (i.e., how big the cell is and how fast the UE is moving). If this is not considered, UEs can experience lots of unnecessary handover (i.e., fast speed UE handed to a small sized neighbor and to be handed over after a very short duration to another neighbor) or even failures (e.g., if handover of a high speed UE to a small sized neighbor is initiated, target cell signal may become very weak by the time handover is completed and failure may occur).
Currently, UE speed information is used to adjust cell reselection (cell reselection thresholds) and handover parameters (TTT) to some extent. First the UE estimates its speed (high, medium, normal, known as the mobility state of the UE) based on MobilityStateParameters configuration received from the eNB, which relates the number of handovers in a given time to a certain mobility state. Thus, in the case of handover, the UE calculates its mobility state and adjusts the TTT accordingly by multiplying the TTT with a scaling factor associated with each mobility state. The drawbacks of this way of handover parameter adjustment, especially in a HetNet scenario are:                The speed calculation based on number of handover is not accurate even in a homogenous network, and it becomes even worse in a HetNet.        All neighbors are treated equally. For example, the UE adjusts the TTT to the same value whether the concerned target is a big macro cell or a very small pico cell.
On top of that, only the TTT is adjusted in a speed dependent manner, and the same CIO is used regardless of the UE's speed, which can greatly undermine the benefit of the adjusted TTT.
From the above it can be deduced that it would be preferable not to handover UEs moving at high speeds to very small coverage cells due to the UE permanence in the cell being likely very short or even due to the high probability of mobility failures due to the target small cell's signal becoming very weak by the time the handover is completed.
Therefore, for UEs moving at high speed it would be advisable to select the handover target cell not only on the basis of the strongest received signal but also on the basis of the risk of handover failure if the target consists of a very small cell. Namely for these UEs the best target would be a wide coverage cell.
However, if source cell mobility parameters such as TTT are adjusted to allow high speed mobility to "jump" small cell targets and to select directly larger coverage cells, this would degrade the mobility performance of low speed UEs. These UEs in fact would need to be handed over to small coverage cells given that they might be able to camp on such cells for a long time while moving at slow speed.
U.S. Provisional Patent application 61/515,225, filed Aug. 4, 2011, entitled "Improved Handover Robustness in Cellular Radio Communications", which is incorporated by reference herein in its entirety, proposes enhancement of current MRO mechanisms that address both the UE speed and the size of the target cell. Therein it is proposed to add to the X2 RLF INDICATION message the cell size of the cell originating the message. This, combined with UE speed information already contained in the UE RLF Report Container IE, allows the receiving node to adjust its target selection criteria based on UE mobility and neighbor cell size. Furthermore, it was also proposed to include the size of the cells involved in mobility and UE RLF Report Container IE in the X2 HANDOVER REPORT message sent from target eNB to source eNB. The source eNB thus becomes aware of UE measurements taken at the time of failure and size of neighboring cells, which allows the source to adjust its mobility thresholds towards neighbor cells and to prioritize certain targets depending on UE mobility. Differentiated target selection for high speed UEs are proposed where a per-UE, per target cell CIO is used or/and target prioritization at the source eNB is made based on previously monitored failure events.
1.5 Cell Size and its Impact on Random Access Operations in LTE
In Wideband Code Division Multiple Access (WCDMA), one of the predecessors of LTE, the Random Access Channel (RACH) is used for initial network access as well as for short message transmission. In LTE, the RACH use is limited only for initial network access, and is used primarily for the UE to acquire uplink time synchronization (in situations such as when the UE is handed over to a target cell, when it goes from IDLE mode to CONNECTED mode, or if it has lost the synchronization due to RLF). An uplink synchronized UE can also use the RACH for the purposes of sending a Scheduling Request (SR) if it doesn't have any other uplink resource allocated in which to send the SR.
Two kinds of RACH procedures are available in LTE, namely contention-based and contention-free. For contention-based RA, the UE randomly chooses a preamble, while a pre-assigned preamble is used for the contention-free cases. Contention free is usually the preferred method for time-critical cases such as synchronization during handover.
There are totally 64 preambles, a certain number of which are reserved for contention free access by the eNB. The ones available for contention-based access are broadcasted to all UEs, while contention-free ones are dedicatedly assigned on need basis.
Four Preambles formats as shown in table 1 are defined for FDD:
TABLE 1RA preamble formats in LTE.PreambleCyclicSequenceSub framesFormatPrefix (μs)duration (μs)requiredCell Range0103.138001up to 14 km1684.388002up to 77 km2203.1316002up to 29 km3684.3816003up to 100 km
Since actual physical transmission occurs in units of sub-frames (1 ms), the remaining time from the sum of the cyclic prefix and sequence duration determines how far away the UE can be without overlapping another UE's access attempt (the guard time) and hence the coverage.
While the RA preamble format determines the length of the preamble, the generation of the actual preamble is mainly determined by the RootSequenceIndex and ZeroCorrelationZoneConfig (which is the cyclic shift to be applied to the root sequence) parameters. Using these two parameters, it is possible to generate sequences that are orthogonal regardless of the delay spread and the time uncertainty of the UEs. Sixteen different cyclic shift values have been defined and the cyclic shift values are also related to the cell range and the relationship is shown in FIG. 3.
1.6 Measurements
1.6.1 UE Measurements
Most measurements in LTE are done by the UE on the serving as well as on neighbor cells over some known Reference Symbols (RS) or pilot sequences. The measurements are done for various purposes. Some example measurement purposes are: mobility, positioning, self organizing network (SON), minimization of drive tests (MDT), operation and maintenance (O&M or OAM), network planning and optimization etc. The measurements may also comprise of cell identification e.g. PCI acquisition of the target, CGI or ECGI acquisition of the target cell, system information acquisition of the target cell, be it an LTE cell or any inter-RAT cell.
Examples of mobility measurements in LTE are:                Reference symbol received power (RSRP)        Reference symbol received quality (RSRQ)
Examples of well known positioning measurements in LTE are:                Reference signal time difference (RSTD)        RX-TX time difference measurement
1.6.2 eNB Measurements
Some measurements may also require the eNB to measure the signals transmitted by the UE in the uplink. One important measurement performed by the eNB in LTE is the estimation of Timing Advance (TA). For LTE, uplink orthogonally is required to avoid intra-cell interference and as such it is important to have all the uplink signals to be time-aligned when they are received at the eNB. Thus, eNBs try to compensate for the propagation delays differences of their UEs (due to their differing distances from the eNB), by instructing them to apply different timing advances, and the UEs will apply the configured timing advance when they are transmitting. The TA can first be estimated during the initial random access procedure when the UE establishes a connection with the eNB (either due to handover or going from IDLE to connected mode). TA updates are then performed throughout the duration the UE is connected to the eNB, as the propagation delay might change, for example due to the movement of the UE, the change of the environment due to movement of other objects in a dense urban setting, etc. For these updates, the eNBs may measure received uplink signals such as Sounding Reference Signals (SRS), Channel Quality Indicator (CQI), ACKs and NACKs in response to downlink data reception, or the uplink data transmission. The details of uplink timing measurements at the eNB are not standardized and left to implementation.
eNBs that have multiple antenna elements could also use their diversity to measure the Angle of Arrival (AoA) of the uplink signals that receive from their UEs. The AoA and TA can be used to estimate the relative co-ordinates of the UEs within the cell.
2.0 Problems with Existing Solutions
As discussed above, including the cell size information in MRO reports can lead to a more accurate configuration of HO parameter that can improve system performance by reducing the occurrence of RLFs and HOFs in HetNets, regardless of the speed of the UEs in the system.
As also discussed above, some rough estimate of the cell size can be made from the random access preambles. However these estimates can only tell the maximum possible cell size that can use such a preamble. Also, the minimum cell size which can be guessed from these is about 800 m (see FIG. 3). As such, it will be impossible to distinguish a pico cell of 50 m radius with an LTE macro cell of 500 m radius because they can both use similar preamble formats and cyclic shifts.
Another problem in using the RA preambles is that the preambles are decided based on the overall coverage area (how much delay the UEs signal could experience). That means in the case of remote site deployments such as Distributed Antenna Systems (DAS), the length of the fibre to the remote cells must be considered as part of the cell radius. Since the speed of electromagnetic waves over fibre is only two thirds of the speeds in free space, the total cell radius reduces the values shown in Table 1.
In a homogenous network that has only macro cells, the cell size can be roughly estimated based on the transmission power used by the eNBs, and they are rather static. However, the effective cell size/shape is highly impacted by the environment. This is illustrated in FIG. 4, where a base station is deployed in a urban-like environment. The base station is installed at a four-way intersection, with a building at each corner. If there were no buildings, the size/shape of the cell would have been as the one depicted in the dashed lines. However, due to the big indoor propagation loss, the effective size/shape of the cell would be reduced to the grey area. Although the example of FIG. 4 shows the impact of static buildings, temporal changes in the environment caused by moving objects, seasonal changes (e.g. the falling of leaves, snow melting, etc.), construction of new buildings, etc. will also impact the effective cell size/shape. Thus, it is very challenging to obtain accurate cell size/shape information during the radio planning phase, and the effective cell size/shape can vary from time to time.
Performing handovers solely based on radio conditions can lead to sub-optimal results, since the cell shape as well as its overlapping region with its neighbours can be highly irregular. As shown in FIG. 5, due to the propagation environment, the three cells have varying shapes. If a UE is leaving cell A in the vicinity of region x, then cell B is the obvious handover candidate. On the other hand, in region Y, if a UE is handed towards cell B from cell A, it is very likely that soon it will have to be handed over to cell C. It might also be possible that the UE (especially if it is moving at high speed) will experience a failure soon after it has been handed over to B. The failure may occur because there may not be sufficient time to perform measurements, report them to eNB B and handover executed properly during the short period that the UE stays in cell B. A handover algorithm that is based only on radio conditions, without considering the neighbor cell shapes and overlapping region might always try to handover a UE from cell A to cell B, whether the UE is approaching cell B in region x or y, possibly causing unnecessary handovers, or even a connection failures.
In HetNets even having detailed information about the environment will not provide accurate cell size/shape information due to two main reasons: Cell Range Expansion (CRE) and the location of small cells relative the macro eNBs.
2.1 Cell Range Expansion
The big differences in the transmit powers of small cells and macros means the downlink coverage of the small cells is much smaller than the macros. However, in the uplink this is not the case because the uplink coverage depends on the received power at the eNBs (be it a pico/femto or macro), and as such it is similar for all eNBs and the uplink handover boundaries can be determined based only on the channel gain (i.e., selecting the node that provides minimum path loss). Thus, the uplink and downlink handover boundaries can be quite different in HetNets, as compared to the homogenous network case in which they are very similar. Due to the small size of pico/femto cells, the path loss between UE and Pico/Femto eNB is relatively small (provided the UE is in proximity of the Pico/Femto cell).
However, the reduced Tx power of such cell might mean that the UE is outside the pico/femto downlink coverage area. This is illustrated in FIG. 6.
If serving cell selection is based only on downlink received signal strength (i.e., RSRP) as in LTE release 8, most of the UEs will select the macros and the small cells may end up serving almost no UEs, which is against one of the primary reasons for installing small cells to begin with, i.e., sharing the load of the macros. Cell Range Extension (CRE) is the expansion of the coverage of the small cell in order to balance the load between the macros and small cells. This can be realized in several ways, for example:                Adjust the transmission power of the small cell depending on the load in the system        Use cell selection offsets and handover thresholds that favour the small cell        Adopting the use of Almost Blank Subframes (ABS) at overlaying macro cell, in order to reduce interference on such subframes (by preventing the macro from transmitting any data traffic) and therefore increase the radio quality of Pico/Femto cell signal to cover a larger area).
With Cell Range Extension (CRE), the best uplink signal will be received by the best node (the small cell) in the expanded cell area, and thus some load is relieved from the macro. However, the downlink interference is high in the expanded cell area. Several advanced interference management techniques, such as interference cancellation at the UE and enhanced Inter-cell Interference Co-ordination (eICIC).
With regard to the reporting of cell sizes, Cell Range Extension (CRE) imposes a problem because the effective cell size of the small cells will be time varying.
2.2 Relative Location of Small Cells
The effective size of the pico cells is also dependent on the relative location of the small cells relative to the macro eNBs. For example, simulation results have shown (which are duplicated in Table 2) that the coverage area of the small cell can vary considerably, by more than threefold, when the small cell is placed 1.5 cell radius away from the macro eNB (where the macro eNB is situated at the far end of the cell) as compared with the case where the small cell is located 0.5 cell radius away.
TABLE 2ESTIMATES OF THE PICO COVERAGE AREA RADIUSFrequencyCell0.5x1x1.5xand ISDselectionradiusradiusradius2 GHz,RSRP 7 m14 m21 m500 m2 GHz,PL16 m33 m50 m500 m700 MHz,RSRP24 m49 m74 m1732 m700 MHz,PL57 m117 m 176 m 1732 m
Thus, two small cells using the same transmission power and range extension settings can end up having quite different effective cell sizes due to differences in their relative location from the macro, and as such it impacts the reporting of cell sizes that is addressed hereinbelow.

Cell size and shape estimation in heterogeneous networks


A catheter includes a catheter shaft having a body portion and a bend that extends distally from a distal end of the body portion. In the catheter, a braid is embedded in the catheter shaft. The braid has a first wire and a second wire woven together. The first wire has a high tensile strength and the second wire has a low tensile strength that is lower than the high tensile strength of the first wire. When viewed from a proximal end of the catheter shaft, the bend forms an arc that extends in a winding direction of the first wire.

The disclosed embodiments relate to a medical device. Specifically, the disclosed embodiments relate to a catheter that is capable of easily changing a proceeding direction from a major canal (a main branch) to a minor canal (a side branch) at a bifurcation.
When a stenosis site or an occlusion site is formed in a tubular organ such as a blood vessel, a bile duct, a pancreatic duct, or the like, the flow of fluid (e.g., blood, bile (biliary fluid), pancreatic juice, or the like) through the tubular organ becomes restricted. As a method of treating the stenosis site or the occlusion site, a treatment method using a catheter has been widely used.
Generally, the number of bifurcations of the major canal and minor canals of a tubular organ increases toward the end portion of the tubular organ. Accordingly, when a stenosis site or an occlusion site is formed at an end portion of a tubular organ, the catheter must be able to easily change its proceeding direction from a major canal (a main branch) to a minor canal (a side branch) at a bifurcation.
To address the above considerations, a known catheter includes a bend at a distal end of a catheter shaft in which the bend is bent obliquely towards a predetermined direction (see Japanese Patent Application Publication No. 2011-83596, for example). By providing such a bend, the distal end of the catheter can be oriented towards a direction that is offset with respect to a plane of the body portion of the catheter shaft.
However, in the catheter of Japanese Patent Application Publication No. 2011-83596, a braid is embedded into the catheter shaft, and includes a first wire and a second wire woven together and having the same wire diameter. Thus, the tensile strength of the first wire and the second wire are the same. Accordingly, regardless of whether a technician rotates the catheter in the clockwise direction or in the counterclockwise direction, the rotational force (torque) transmitted to the distal end of the catheter is the same. In other words, the rotational force is isotropic. With such a catheter, when the distal end of the catheter fails to enter a minor canal and is caught by a portion around the entrance of the minor canal at a bifurcation, the bend of the catheter shaft cannot be deformed when the technician rotates the catheter because the rotational force is isotropic. Accordingly, the distal end of the catheter cannot be easily inserted into the minor canal, and it takes time to change the proceeding direction of the catheter from the major canal to the minor canal.


A semiconductor module (10) includes a heat sink (1), an electronic component (2), a semiconductor device (3), and a thermally-conductive sheet member (4). The thermally-conductive sheet member (4) covers a part of the semiconductor device (3) and has a lower part (4b) and a side part (4c). The lower part (4b) is in contact with a mounting face (11a) of the heat sink (1). The side part (4c) extends from the lower part (4b) and covers a first side surface (3c) of the semiconductor device (3). The electronic component (2) is disposed across the side part (4c) of the thermally-conductive sheet member (4) from the semiconductor device (3).

Semiconductor power modules (semiconductor modules) have conventionally been thermally designed, for example, in the following manner: In order to cool a semiconductor power device (a semiconductor device which generates heat by the operation of a semiconductor power module and consequently the temperature of which becomes high) and keep the above temperature below the safe operating temperature of the semiconductor power module, the semiconductor power device is brought into contact with a package base material (a heat sink). Accordingly, in the case where a power module is constructed by using a plurality of semiconductor power devices, it is necessary to bring every semiconductor power device into contact with a package base material.
Furthermore, semiconductor power modules include a module configured so that a semiconductor power device and a control circuit for controlling the semiconductor power device or a passive component, such as a capacitor, are mounted on the same package base material. For example, Patent Document 1 discloses a power converter (semiconductor module) 80 configured so that, as shown in FIGS. 24(a) and 24(b), a main circuit (semiconductor device) 83 and a control circuit 82 are contained in the same package 81. In the power converter 80 shown in FIG. 24(a), a plate-like shield 88 is inserted between the main circuit 83 and the control circuit 82, thereby blocking heat and electromagnetic noise both generated by the main circuit 83.
Patent Document 1 also discloses the following configuration: In a power converter 180 shown in FIG. 24(b), a U-shaped shield 188 is placed in the package 81 to section the package 81 into two parts. In this configuration, the shield 188 completely covers the heat-generating main circuit 83. Moreover, through holes are formed in the shield 188. A signal line 189 for electrically connecting the control circuit 82 or a passive component located outside the shield 188 to a semiconductor power device, a signal line 189 for supplying a control signal from the control circuit 82 or a passive component located outside the shield 188 to a semiconductor power device, or any other element passes through each of the through holes.
Patent Document 1: Japanese Unexamined Patent Application Publication No. 2005-235929

Semiconductor module and method for fabricating semiconductor module


A surface treatment method can perform coated surface treatment on a cutting edge R and a rake surface, while maintaining a radius of curvature of the cutting edge R and uniformly surface-treating the rake surface. The surface treatment method includes providing an opening chamfered at corners adjacent to an upper surface of the fixture to the fixture for fixing a coated cutting insert; fixing the coated cutting insert inside the opening in such a manner that a rake surface of the coated cutting insert is disposed lower than upper surfaces of the fixture but higher than a lower edge created on the opening of the fixture by the chamfering; and conducting the surface treatment on a cutting edge R and the rake surface of the coated cutting insert.

Surface treatment is conducted on a coated cutting insert in order to remove coated surface defects and improve surface roughness, thereby reducing cutting resistance and preventing the fusion of the coated surface with a work piece. Conventionally, cutting inserts coated with CVD or PVD have been surface-treated by methods of blasting, polishing, brushing and the like. For such surface treatments, the coated cutting insert is fixed within a fixture, as shown in FIG. 1.
The conventional fixture (2) seizes only a lower part of a cutting insert (4), while an upper part of the cutting insert (4) partially protrudes from an upper surface of the fixture (2). By doing so, the insert (4) is surface-treated by brushing and the like. For example, a rotating brush can be used for surface treatment. During surface treatment by a rotating brush, the cutting edge R (6) is subject to a larger load compared to that of a rake surface (8) (the load mainly includes a pressure force of the brush and partially includes an impact or frictional force from the brush). This is because the rotating brush, which has a relatively large impact with rotating, hits the protruding cutting edge R (6) first and brushes the cutting edge R (6) with a relatively large load, wherein the brush then proceeds to brush the rake surface (8) with a relatively reduced impact and load. For this reason, the brushing load of the rotating brush is concentrated on the cutting edge R (6) rather than on the rake surface (8). Accordingly, the honed amount (H) (indicating an amount of wearing at the cutting edge R, which is usually measured as a straight distance from a starting point to an end point of the cutting edge R, along the surface perpendicular to a lower surface of the insert) or the radius of curvature of the cutting edge R increases after the surface treatment (rather than before such a treatment), even if the surface treatment period, brushing pressure, rotation speed and the like are controlled. In particular, the portion adjacent to the rake surface (8) of the cutting edge (R) is more severely worn out during the surface treatment compared to the portion adjacent to the flank surface (10). As a result, the curvature radius adjacent to the rake surface (8) of the cutting edge (R) becomes asymmetrically larger than that of the portion adjacent to the flank surface (10).
As the curvature radius of the cutting edge R becomes larger during the surface treatment, there is a problem in that the cutting performance of the cutting insert is degraded and precise machining cannot be performed. This deteriorates the surface roughness of a work piece. In particular, if the curvature radius of the cutting edge R, which should be kept as small as possible, becomes larger in a PVD-coated cutting insert, then the cutting performance of the PVD-coated cutting insert is remarkably degraded.
Further, in the conventional fixture structure, since the insert (4) is disposed protruding from the fixture (2), the load for surface treatment is concentrated on the insert (4) rather than the fixture (2). If the load (e.g., from a rotating brush) is concentrated on the rake surface of the insert, which has chip breakers (not shown) of a highly curved shape, then the protruded portion on the rake surface is subject to a larger load than the recessed portion on the rake surface. Accordingly, the protruding portion is severely worn out relative to the recessed portion and the coated surface of the rake surface is non-uniformly treated. As such, in the conventional fixture structure wherein the insert is fixed protruding from the fixture, it is difficult to achieve a surface treatment that is uniformly conducted on the rake surface having chip breakers of a curved shape. A coated rake surface having chip breakers contacts and bends cutting chips generated during the cutting process, thereby controlling the discharge of cutting chips. The non-uniformly treated and coated rake surface obstructs the smooth discharge of cutting chips, thereby resulting in the degradation of cutting performance.
As such, according to the conventional surface treatment method, the curvature radius of the cutting edge R becomes larger and the rake surface is not uniformly treated. Thus, the cutting performance of the coated cutting insert is degraded and the life of the coated cutting insert is reduced.
An object of the present invention is to provide a new surface treatment method, which can perform coated surface treatment on a cutting edge R and a rake surface, while maintaining a radius of curvature of the cutting edge R and uniformly surface-treating the rake surface.

Surface treatment method for coated cutting insert


An image processing apparatus includes an image processing unit configured to process an image; an input unit configured to input a start-up instruction to the image processing unit; a detection unit configured to detect that a first electric power is supplied in a case where a supply cable is connected to an electrical outlet in a state of separation of the cable from the outlet; a first non-volatile storage unit and a second volatile storage unit configured to store first and second values, respectively, the first and second values indicating whether being in a valid state for receiving the start-up instruction; a determination unit configured to determine whether the first value indicates the valid state and is different from the second value; and a control unit configured to restrict a second electric power supplied to the image processing unit, and to bring the image processing apparatus into the valid state.

1. Field of the Invention
The disclosures herein generally relate to an image processing apparatus, a control method and a computer-readable recording medium storing a program for causing a computer to execute a process.
2. Description of the Related Art
Image processing apparatuses such as PCs (personal computers), which perform various processes, store various kinds of setting information used upon the processes. Moreover, as the setting information, network setting information or the like for the image processing apparatus establishing a network connection via, for example, the Ethernet (trademark registered), Wi-Fi (Wireless Fidelity) or the like is stored. Furthermore, as the setting information, for example, so-called "Wake-on-LAN" setting information or the like for permitting an other image processing apparatus, which is connected to the image processing apparatus via a LAN (Local Area Network) or the like, to remotely operate a power source of the image processing apparatus is stored.
Japanese Published Patent Application No. H06-334699, for example, discloses, as an example of using setting information related to the Wake-on-LAN function, a method of setting a time zone in which turning on a main power source by the Wake-on-LAN function is permitted.

Image processing apparatus, control method and recording medium, to control display of state or setting information


An active CMOS biosensor chip for fluorescent-based detection is provided that enables time-gated, time-resolved fluorescence spectroscopy. In one embodiment, analytes are loaded with fluorophores that are bound to probe molecules immobilized on the surface of the chip. Photodiodes and other circuitry in the chip are used to measure the fluorescent intensity of the fluorophore at different times. These measurements are then averaged to generate a representation of the transient fluorescent decay response unique to the fluorophores. In addition to its low-cost, compact form, the biosensor chip provides capabilities beyond those of macroscopic instrumentation by enabling time-gated operation for background rejection, easing requirements on optical filters, and by characterizing fluorescence lifetime, allowing for a more detailed characterization of fluorophore labels and their environment. The biosensor chip can be used for a variety of applications including biological, medical, in-the-field applications, and fluorescent lifetime imaging applications.

1. Technical Field
The present invention relates to fluorescent-based detection. More particularly, the present invention relates to systems and methods for providing time-gated, time-resolved fluorescent-based detection on an active complementary metal oxide semiconductor (CMOS) biosensor chip.
2. Description of the Related Art
An assay is a qualitative and/or quantitative analysis of an unknown analyte. In one example, an assay can be a procedure that determines the concentration and sequences of DNA in a mixture. In another example, an assay can be an analysis of the type and concentrations of protein in an unknown sample.
Surface-based sensing assays are typically performed in environmental and biomedical diagnostics. The detection of analytes (targets) in a mixture is often implemented at a solid-liquid interface. Passive solid supports, which include glass substrates or polymer membranes, have probe molecules (i.e., "probes") immobilized on the surface of the solid supports that are used to bind the analytes of interest. Probes include, for example, proteins and nucleic acids. Probes are selected based on the analytes of interest such that there is a strong and specific interaction between a particular type of probe and a particular target.
More than one analyte can be detected using multiplexed detection. In multiplexed detection, different types of probes are arranged in an array on the surface of the solid supports. Each type of probe results in a strong and specific interaction with a different analyte of interest. For example, in DNA analysis, high density microarrays are used to examine gene expressions at the scale of entire genomes by simultaneously assaying mixtures derived from expressed mRNA against thousands of array sites, each bearing probes for a specific gene. Microarrays generally quantify target concentrations in relative terms, for example, in the form of a ratio to hybridization signal obtained using a reference target sample. Other biosensing applications are calibrated to provide absolute target concentrations.
Fluorescent-based detection is commonly used for quantifying the extent of probe-target binding in surface-based sensing assays. In fluorescent-based detection, a target is labeled with a fluorophore molecule, which can cause the target fluorophore to be fluorescent. Traditional microarray scanners include an excitation source, such as a laser, that emits light on the bound target fluorophores. This causes the target fluorophores to emit fluorescent light that is focused and collected (through a generally lossy optical path) onto a cooled charge-coupled device (CCD) or a photomultiplier tube (PMT). Optical filtering is typically used to improve the signal-to-noise ratio (SNR) by removing background light or reflected excitation light. In addition, the arrays are generally sensitive to particular fluorophore concentrations from 108 to 1011 cm−2.
Characteristic lifetimes are associated with each fluorophore. The lifetime is defined by the transient exponential fluorescent decay of the fluorophore once the excitation source is removed. The lifetime, which is typically on the order of nanoseconds for organic dyes, is characteristic of the dye and the environment, and can be used in addition to color and intensity for multiplexed detection. Quantum-dot fluorophores can have lifetimes exceeding 15 nanoseconds at the cost of slightly lower quantum yields. Fluorescent lifetime detection, for example, has been employed for capillary electrophoresis in both the time and frequency domain. Fluorescent lifetime is also sensitive to excited-state reactions, such as fluorescent resonance energy transfer (FRET), which allows for the detection of macromolecular associations labeled by two different fluorophores. For micro-arrays, FRET can be used to detect in situ real-time hybridization kinetics in which both the probe and target are fluorophore-labeled.
In most commercial time-resolved systems, PMT detectors use time-correlated single photon counting (TCSPC). In this case, sensitivity is limited by a dark count, which is typically about 400 Hertz (Hz). For a typical peak quantum efficiency of 25%, this corresponds to a detection limit of approximately 2×105 photons/cm2 sec (i.e., 5×10−7 lux) for an SNR of 20 decibels (dB). For an effective lifetime measurement, a detection limit of at least ten times this can be expected. The time resolution (as determined by the full width at half maximum (FWHM) of the impulse response of the PMT) is limited by jitter in the PMT and instrumentation, and can be less than 50 picoseconds (ρs).
The response of the fluorophore is characterized by the absorption cross-section and quantum yield. Typical fluorophores have cross-sections between 2×10−17 cm2 and 8×10−16 cm2, corresponding to molar extinction coefficients between ε=50,000 cm−1M−1 and 200,000 cm−1M−1. Typical fluorophores also have quantum yields (η) of between 0.05 and 1.0. For example, for η=0.5 and ε=50,000 cm−1M−1, under steady-state illumination, a detection limit of 2×106 photons/cm2 sec could correspond to surface detection limits down to 2×102 molecules/cm2 with an excitation power of 1020 photons/cm2 sec. Detection limits this low are said to characterize single-molecule detection capabilities. Actual detection limits are usually several orders of magnitude greater than this and are limited by background—either the effectiveness of optical filtering in removing the excitation wavelength or in removing stray fluorescence. Lower excitation power also results in higher detection limits.
Known surface-based sensing assays are typically provided on external, macroscopic instruments. Such instruments are often expensive, large, and complex.
Therefore, there is a need in the art to provide a low cost, compact, and integrated chip for surface-based sensing arrays that provides capabilities similar to those on the macroscopic instruments.
Accordingly, it is desirable to provide methods and systems that overcome these and other deficiencies of the prior art.

Active CMOS biosensor chip for fluorescent-based detection

The Trustees of Columbia University in the City of New York


A self service data interface includes communications logic providing communications with a personal data device and a data infrastructure, such as the computer resources in a department or building. A processor executes a data interface management process that communicates with the data infrastructure to obtain information about available data services, where the information includes information about how the available data services are accessed. The data interface management process also communicates with the personal data device to provide the information about the available data services to the user. The information is used by the personal data device to invoke the services directly via the self service data interface. The self service interface can have multiple communications links to the personal data device, such as a wire link and a wireless link. The information from the self service data interface can be provided as a hypertext page that is accessed and handled by a browser within the personal data device.

The present invention is related to the field of communications between a personal data device such as a personal or hand-held computer and a data infrastructure such as a computer network in a company or building.
Increasingly, computer networks are being used by organizations in conducting their internal and external business activities. As the use of computer networks has grown, demand for skilled workers to operate and maintain the networks has increased significantly. Organizations are faced with significant costs of attracting and retaining necessary workers, and uncertainty whether the organizations' needs for skilled workers can be met at all. These costs and uncertainties may render it difficult or impossible for some organizations to make desired investments in computer networking technology. Such organizations may be placed at a competitive disadvantage, or may find that their very viability has become uncertain.


A tablet cassette in which a tablet is not discharged during a mounting or dismounting operation of the tablet cassette. The tablet cassette (1) incorporates a rotor (6) having pocket portions (7) for holding tablets (T). When the tablet cassette 1 is mounted on a mount base (2), rotation of the rotor (6) causes the tablets (T) held in the pocket portions (7) to be discharged though a discharge port (8). The tablet cassette (1) includes a press member (16) which is pressed when the tablet cassette (1) is mounted on the mount base (2) and a rotor reversing member (19) for reversing the rotor (6) by a predetermined quantity in conjunction with pressing of the press member (16).

1. Technical Field
The present invention relate to a tablet cassette to be mounted on a tablet packing apparatus in which tablets are dispensed and packed in accordance with a prescription of a patient.
2. Description of Related Art
Conventionally, in a tablet packing apparatus, a plurality of tablet feeders are provided for every kind of tablets. Each tablet feeder comprises a tablet cassette for containing a number of tablets and a mount base on which the tablet cassette is mounted. The tablet cassette has a rotor. The outer surface of the rotor is formed with a plurality of pocket portions, each of which comprises a groove extending in an axial direction so as to hold the tablets. On the shaft of the rotor protruding downward from the bottom of the tablet cassette, a rotor gear is attached. On the bottom of the tablet cassette is attached an intermediate gear which engages with the rotor gear. In the rear portion of the bottom of tablet cassette is formed a discharge port which communicates with the pocket portions of the rotor. On the other hand, a motor is incorporated in the mount base. The shaft of the motor protrudes upward. A drive gear is fixed on the upper end of the shaft. When the tablet cassette is mounted on the mount base, the intermediate gear of the tablet cassette engages with the drive gear of the mount base. Driving the motor allows the rotor to rotate via the drive gear, the intermediate gear and the rotor gear. When the pocket portion reaches the discharge port, the tablet held in the pocket portion is discharged thorough the discharge portion and led to a packing unit though a discharge path in the mount base. When the tablet cassette is dismounted or removed from the mount base for replenishment of the tablet or inspection, the intermediate gear of the tablet cassette is disengaged from the drive gear of the mount base, thereby allowing the rotor to freely rotate. Thus, there has been a possibility that the rotor will unexpectedly rotate due to impact or vibration to cause the tablet held in the pocket of the rotor to drop from the discharge port into the packing unit, resulting in the tablet being packed in a state contaminated by other tablets.
Conventionally, there have been various suggestions for preventing the rotor from unexpectedly rotating when mounting and dismounting the tablet cassette. For example, JP 9-30501A discloses a restraint means for engaging with a gear of a rotor due to its elasticity to restrain self-rotation of the rotor when a tablet cassette is dismounted. The document also discloses a release means for releasing the engagement of the restraint means with the rotor when the tablet cassette is mounted.
The JP 9-323702A, which was filed by the same applicant as the present application, discloses an elastic engagement member that engages with a gear of a rotor to prevent the rotation of the rotor when a tablet cassette is dismounted, and an engagement release member provided on the elastic engagement member that comes into press contact with a proper position of a guide rail of a mount base to release the engagement of the elastic engagement member with the gear when the tablet cassette is mounted.
JP 10-314277A discloses an engagement means that directly engages with and disengages from a rotor so that the engagement means engages with a peripheral wall of a rotor when a tablet cassette is dismounted and disengaged from the rotor when the cassette is mounted.