On the Decode-and-Forward Cooperative Diversity with Coherent and Non-Coherent UWB Systems

In this paper, we extend the decode-and-forward cooperative diversity scheme to the context of impulse radio ultra-wideband (IR-UWB). We develop coherent and non-coherent schemes that exploit the spatial diversity in a distributed manner among the different terminals of a wireless network. These schemes are specific to IR-UWB and they take advantage of the pulse repetitions used to convey each information symbol. If N_f is the number of pulses per symbol, the coherent scheme is based on joint symbol and pulse coding and it achieves full diversity with any number of relays for N_f>1. The non-coherent scheme is based on pulse coding and it achieves full diversity with a maximum number of N_f-1 relays