Over-sampled Multi-channel MMSE Equalization for Better Multi-user Performance for Multi-band UWB

Multi-band ultra-wideband (MB-UWB) divides the available spectrum into multiple subbands, in which certain bands may be turned off to eliminate possible interference and coexistence problems with other wireless services using the same spectrum. Another possibility arising from MB-UWB is the assignment of different time-frequency subband hopping patterns to support simultaneously operating piconets (SOPs). Due to the long delay spread of UWB channels, it is difficult to ensure no collision among the SOPs within a subband even with a non-overlapping subband hopping pattern. This paper presents the performance of an over-sampled multi-channel MMSE equalizer in the presence of multiple access interference (MAI), under various collision scenarios and channel models, with RAKE receiver as a comparison baseline. It has been shown that the oversampled MMSE receiver is also suitable for MAI mitigation, in addition to suppression of inter-symbol interference (ISI).