Efficient scheme for DOA estimation of multipath clusters in WiMedia UWB systems

Abstract

UWB systems are expected to find widespread use in future short range applications. Increasing popularity of these devices will require management of occupied spectrum in spatial domain to keep the interference low. In Ultra Wide Band (UWB) communication systems, one encounters many multipath components. By optimally forming beams in the direction of the principal multipath clusters, one can achieve optimum spectrum efficiency. The number of components would depend on the sampling rate as the number of resolvable components depends on it. Besides, many of the multipath components would be coming from the same cluster. The estimation of the Direction of Arrival (DOA) of these clusters is very useful to focus the transmit power in the optimum direction. A new algorithm, exploiting the known pilot signals of multiband UWB systems for estimation of DOA of clusters is proposed recently. By making use of a new matrix incorporating the cross correlation between the focused UWB signal and the known pilot signal of the transmitted data in each array element, one would be able to separate the multipath clusters from a single source. This paper looks at reducing the number of receivers required for implementing the algorithm. UWB System makes use of the preample to synchronize the incoming data. Hence, one can employ a central processor to sample the data from individual sensors in a time multiplexed fashion. This time multiplexed sampled data can be used for finding the expected value of correlation with known reference data. This would allow usage of fewer receivers to achieve the same level of performance. Computer experiments are included to verify the performance of the proposed algorithm with and without receiver time multiplexing.