Detection of TR-UWB by Recursion in Dense Multipath

For the ultra-wideband (UWB) communication, the Rake receiver could efficiently collect the spread energy from the diversity of channel environment. Unfortunately, the overload of correlator is too huge to retain the diversity gain, and the channel estimation and timing acquisition are hard to achieve. Therefore, a suboptimal solution for UWB transmission was proposed by using transmitted-reference (TR), for which neither complex channel estimation nor pulse information is needed. From the noisy-template (NT) of TR-UWB, the correlator could efficiently detect information data but the NT is strongly affected by noise. We can improve the NT by the approach that averages all TR's as the averaged NT (ANT) during the reasonable delay, with only half of the transmission rate. Moreover, the ANT should be constrained by the quasi-static period of channel. For this reason, we propose an algorithm for the situation of the short quasi-static period of channel. Based on our algorithm, the finite data could be taken and decided as pilots, like TR's, by a discriminator with a threshold. Further, the modified clustered channel estimation (MCCE) [8] gives the improvement of performance by the regional autocorrelation decision. The proposed algorithm is verified by the error probability analysis and the simulations. With only a few TR's and low complexity buffer, we could obtain good error performance in the uncorrelated rapid-varying dense multipath.