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In this paper, we evaluate the performance of both uncoded and coded multiple access TH-UWB systems introduced in [1-3], in multipath Rayleigh fading channels. The receiver is a selective diversity combining receiver, known as SRake. Based on Gaussian distribution assumption for the multiple access interference at the output of SRake receiver and by using virtual branch technique as introduced in [4-5], the hit error rates for uncoded and coded schemes are derived. Our analysis shows that the effective order of diversity achieved by the coded scheme is the product of the number of branches of SRake receiver and the Hamming distance of the code applied. Furthermore, it indicates that the... 

A simulation tool, based on Ray Tracing method, has been developed and validated for millimeter-wave band. This tool helps for predicting the signal level as well as the delay characteristics of a propagation channel. Since the resultant of the received replicas of the transmitted signal at receiver point can experience a deep fade and consequently the quality degradation, a proper diversity method can effectively alleviate this drawback. Using this simulation tool and extracting the received wave characteristics in a street scenario, an analytical expression for predicting the space diversity gain for the Selection Combining technique and Maximal-Ratio Combining technique has been proposed