tailieunhanh - Báo cáo hóa học: " A Low-Complexity Joint Synchronization and Detection Algorithm for Single-Band DS-CDMA UWB Communications Lars P. B. Christensen"

Tuyển tập báo cáo các nghiên cứu khoa học quốc tế ngành hóa học dành cho các bạn yêu hóa học tham khảo đề tài: A Low-Complexity Joint Synchronization and Detection Algorithm for Single-Band DS-CDMA UWB Communications Lars P. B. Christensen | EURASIP Journal on Applied Signal Processing 2005 3 462-470 2005 Hindawi Publishing Corporation A Low-Complexity Joint Synchronization and Detection Algorithm for Single-Band DS-CDMA UWB Communications Lars P. B. Christensen Information and Mathematical Modelling Technical University of Denmark 2800 Kongens Lyngby Denmark Email lc@ Received 1 October 2003 Revised 2 June 2004 The problem of asynchronous direct-sequence code-division multiple-access DS-CDMA detection over the ultra-wideband UWB multipath channel is considered. A joint synchronization channel-estimation and multiuser detection scheme based on the adaptive linear minimum mean square error LMMSE receiver is presented and evaluated. Further a novel nonrecursive least-squares algorithm capable of reducing the complexity of the adaptation in the receiver while preserving the advantages of the recursive least-squares RLS algorithm is presented. Keywords and phrases ultra-wideband direct-sequence code-division multiple-access multiuser detection low-complexity adaptive receivers synchronization. 1. INTRODUCTION Over the last couple of years the interest in ultra-wideband UWB wireless communications has been growing. Among the reasons for this increased awareness of UWB are the promises of low-power high-bitrate wireless connections without the need for spectrum allocation and the approval of the technology by authorities as for example the American FCC 1 . UWB signals for wireless communication typically have a bandwidth of several GHz and can be utilized in many ways each presenting the designer with tradeoffs between cost power bitrate range and the number of users supported. The system considered in this paper is a single-band UWB direct-sequence code-division multiple-access DS-CDMA receiver with all signal processing done on the received signal sampled directly from an amplified and filtered antenna signal. This enables the removal of traditional up- and downconverters present in today s .