A Low Complexity and Effective Rapid Channel Tracking Scheme for UWB Multiple-Access Systems

Ho-Lung Hung,Chien‐Hong Cheng

doi:10.1007/s11277-013-1544-7

Abstract

In this paper, the applicability of the subspace-based blind adaptive algorithm in multiple access ultra-wideband systems is investigated. However, in the multiuser transmission environment, multiple access interference becomes a serious issue and results in the degradation of system performance. In order to overcome this shortcoming, we propose a novel and low complexity decision mechanism, termed the decision timing instant (DTI). A major advantage of the DTI algorithm is that it admits an adaptive implementation with low computational complexity instead of singular value decomposition. In the present paper, we exploit the joint blind multiuser detection in UWB systems, a combined scheme is proposed, which couples the minimum-mean-square-error and the DTI subspace tracking algorithm under UWB time-variant channels. Simulation results show that DTI is able to fast and precisely trace the variation of the channel environment and to improve the performance of the blind adaptive multiuser detection with a subspace approach over time-varying channels.

Highlights

Ultra-wideband (UWB) technology is currently regarded as an attractive solution for many wireless applications where high resolution, reduced interference, and propagation around obstacles are challenging [1,2,3]
We proposed blind multiuser methods based on decision timing instant (DTI) and MMSE procedures
Our novel multiuser detector matched to the DTI has great potential for deployment in future gray curve blue curve pink curve t=2013 yellow curve

Summary

Introduction

Ultra-wideband (UWB) technology is currently regarded as an attractive solution for many wireless applications where high resolution, reduced interference, and propagation around obstacles are challenging [1,2,3]. The research of UWB systems has recently attracted a significant interest in both the academic and industrial community [1,2,3]. It utilizes ultrashort pulse shapes transmitted at a very low power spectral density (PSD) in compliance H.-L. Much research work has been devoted to accelerating the acquisition process of UWB signals. Most existing approaches employ correlators to correlate the received signal with a template signal [13] This technique appears very powerful, but not so satisfactory in a multipath and multiple access channels. Both of the unknown multiple access interference (MAI) and the multipath distortion need to be mitigated

Methods

Findings

Discussion

Conclusion