tailieunhanh - Báo cáo hóa học: " Performance Analysis and Comparison of Time-Hopping and Direct-Sequence UWB-MIMO Systems"

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:Performance Analysis and Comparison of Time-Hopping and Direct-Sequence UWB-MIMO Systems | EURASIP Journal on Applied Signal Processing 2005 3 328-345 2005 Hindawi Publishing Corporation Performance Analysis and Comparison of Time-Hopping and Direct-Sequence UWB-MIMO Systems W. Pam Siriwongpairat Department of Electrical and Computer Engineering University of Maryland College Park MD 20742 USA Email wipawee@ Masoud Olfat Department of Electrical and Computer Engineering University of Maryland College Park MD 20742 USA Email molfat@ K. J. Ray Liu Department of Electrical and Computer Engineering University of Maryland College Park MD 20742 USA Email kjrliu@ Received 15 October 2003 Revised 5 April 2004 We analyze the performance of ultra-wideband UWB multiple-input multiple-output MIMO systems employing various modulation and multiple access MA schemes including time-hopping TH binary pulse-position modulation BPPM TH binary phase-shift keying BPSK and direct-sequence DS- BPSK. We quantify the performance merits of UWB space-time ST systems regardless of specific coding scheme. For each modulation technique we introduce a framework that enables us to compare UWB-MIMO systems with conventional UWB single-input single-output SISO systems in terms of diversity and coding gains. We show that the combination of ST coding and RAKE receiver is capable of exploiting spatial diversity as well as multipath diversity richly inherent in UWB environments. In addition we adopt the real orthogonal design ROD as the engine code for UWB-ST codes. We find the upper bound of the average pairwise error probability PEP under the hypothesis of quasistatic Nakagami-m frequency-selective fading channels. The performance comparison of ROD-ST codes with different rates is also addressed. Finally simulation results are presented to support the theoretical analysis. Keywords and phrases ultra-wideband time hopping direct sequence UWB-MIMO multiple antennas space-time coding. 1. INTRODUCTION Ultra-wideband UWB technology has recently gained .