er radio signals over its wide bandwidth, High immunity to interference from other radio systems, Low probability of interception/detection by other than the desired communication link terminals, High multipath immunity, Many high data rate ultra-wideband channels can operate concurrently, Fine range-resolution capability, Relatively simple, low-cost construction, based on nearly all digital architectures. FREQUENCY Transmission and reception methods are unique, and are described briefly below. Figure 5.2-28 Spectrum of monopulse. Short-range wireless applications and technologies CHAPTER 5.2 network. Figure 5.2-29 is a simulation of a sequence of synchronized sequence generated in the receiver is drawn UWB pulses created by stimulating a bandpass filter with on the second line and below it the result of the corre- a pseudo-randomly spaced sequence of impulses. The lation operation Sf(t) g(t) dt where f(t) is the received figure also shows the power spectrum of that sequence. signal and g(t) is the locally generated sequence. By The network that creates the individual UWB pulses sampling this output at the end of each bit period and includes the transmitter antenna, the propagation chan- then resetting the correlator, the transmitted sequence is nel, and the receiving antenna, whose characteristics, in reconstructed in the receiver. terms of impulse response or amplitude and phase VS. As mentioned above, an individual bit can be repre- frequency must be known and accounted for in designing sented by more than one sequential monopulse. Doing so the system. increases the processing gain by the number of monop- There are several ways of representing a UWB pulse as ulses per bit. Processing gain is also an inverse function of "1" or "0." One method is to advance or retard the the pulse duty cycle. This is because, for constant average transmitted pulse with respect to the expected time of power, the power in the pulses contributing to each bit arrival of the pulse in the receiver according to the agreed must be raise