tailieunhanh - Báo cáo hóa học: " Adaptive Zero-Padding OFDM over Frequency-Selective Multipath Channels"

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: Adaptive Zero-Padding OFDM over Frequency-Selective Multipath Channels | EURASIP Journal on Applied Signal Processing 2004 10 1478-1488 2004 Hindawi Publishing Corporation Adaptive Zero-Padding OFDM over Frequency-Selective Multipath Channels Neng Wang Department of Electrical and Computer Engineering Queen s University Kingston Ontario Canada K7L 3N6 Email nwang@ Steven D. Blostein Department of Electrical and Computer Engineering Queen s University Kingston Ontario Canada K7L 3N6 Email sdb@ Received 28 February 2003 Revised 22 August 2003 We present a novel bandwidth BW efficient orthogonal frequency division multiplexing OFDM scheme with adaptive zeropadding AZP-OFDM for wireless transmission. Redundancy issues in OFDM based on cyclic prefix CP zero-padding ZP as well as no guard interval NGI systems are analyzed. A novel system design criterion based on the channel matrix condition is studied and applied to the design of an AZP-OFDM system. Simulation results have shown that the proposed AZP-OFDM offers performance similar to that of CP-OFDM complexity similar to that of ZP-OFDM with BW efficiency higher than that of both CP- and ZP-OFDM in channels with small to moderate delay spread. In channels with large delay spread AZP scheme adaptively maintains high performance at the expense of BW efficiency. Essentially AZP-OFDM offers a more flexible tradeoff between symbol recovery BW efficiency and complexity. Keywords and phrases bandwidth efficiency cyclic prefix equalization multipath channels orthogonal frequency division multiplexing OFDM zero-padding. 1. INTRODUCTION Orthogonal frequency division multiplexing OFDM has been receiving growing interest in recent years and has been adopted in many standards. For example OFDM has been chosen as a solution for digital audio and video broadcasting DAB and DVB in Europe and applied for high-speed digital subscriber line DSL modems over twisted pairs ADSL HDSL and VDSL . Recently it has also been proposed for digital cable television systems and adopted in new .