Multi-code ultra-wideband signaling using chirp waveforms

We propose an ultra-wideband (UWB) scheme that employs chirp waveforms. Signals satisfying the FCC requirements for UWB applications are formed by using multiple linear frequency-modulated (chirped) waveforms. This scheme has the merits of both the multi-band orthogonal frequency division multiplexing (OFDM) UWB scheme such as continuous-wave transmission, and the pulsed UWB scheme such as accurate timing for position location and rich resolvable multipath components. Another advantage unique to the proposed scheme is that passive, low-cost implementation of matched filters/correlators using surface acoustic wave devices is possible, whereas OFDM-UWB must rely on high-speed sampling combined with powerful digital signal processing. We present the details of chirp waveforms for UWB signaling, explore the correlation properties of the multi-codes, study the receiver structures, and simulate the error performance of the proposed scheme in indoor multipath fading environments