tailieunhanh - Báo cáo hóa học: " Efficient Sequence Detection of Multicarrier Transmissions over Doubly Dispersive 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: Efficient Sequence Detection of Multicarrier Transmissions over Doubly Dispersive Channels | Hindawi Publishing Corporation EURASIP Journal on Applied Signal Processing Volume 2006 Article 1D93638 Pages 1-17 DOI ASP 2006 93638 Efficient Sequence Detection of Multicarrier Transmissions over Doubly Dispersive Channels Sung-Jun Hwang and Philip Schniter Department of Electrical and Computer Engineering The Ohio State University Columbus OH 43210 USA Received 2 June 2005 Revised 1 May 2006 Accepted 12 May 2006 We propose a high-spectral-efficiency multicarrier system for communication over the doubly dispersive DD channel which yields very low frame error rate FER with quadratic in the frame length receiver complexity. To accomplish this we combine a non- bi orthogonal multicarrier modulation MCM scheme recently proposed by the authors with novel sequence detection SD and channel estimation CE algorithms. In particular our MCM scheme allows us to accurately represent the DD channels otherwise complicated intercarrier interference ICI and intersymbol interference ISI response with a relatively small number of coefficients. The SD and CE algorithms then leverage this sparse ICI ISI structure for low-complexity operation. Our SD algorithm combines a novel adaptive breadth-first search procedure with a new fast MMSE-GDFE preprocessor while our CE algorithm uses a rank-reduced pilot-aided Wiener technique to estimate only the significant ICI ISI coefficients. Copyright 2006 Hindawi Publishing Corporation. All rights reserved. 1. INTRODUCTION In wireless data communication the information signal undergoes multipath propagation which due to variations among path lengths induces a time-domain spreading effect on the information signal. Furthermore relative motion between the transmitter receiver and scattering objects imparts each path with a unique Doppler shift so that multipath propagation also induces a frequency-domain spreading effect on the information signal. We refer to such channels as doubly dispersive DD . Reliable high-spectral-efficiency .