MLSE Post-Detection for ISI Mitigation and Synchronization in UWB Low Complexity Receivers

A wireless body area network with an average throughput of 1 Mbps is considered based on ultra-wideband pulse position modulation. For a long battery autonomy, a low duty cycle operation of the nodes and thus, a high peak data rate is essential. Due to the moderate path loss, a peak data rate in excess of 50 Mbps is feasible within the Federal Communications Commission´s transmit power constraints. However, with current low complexity pulse position detectors, such as the energy detector, the peak data rate is constrained to much lower values, because they are very sensitive to intersymbol interference. To overcome this constraint a simple post-detection maximum-likelihood sequence estimator is introduced which significantly reduces the impact of intersymbol interference. The same maximum likelihood sequence estimator is then used to replace cumbersome synchronization algorithms at the expense of slight performance losses.