tailieunhanh - Báo cáo hóa học: "Research Article Analysis of Vector Quantizers Using Transformed Codebooks with Application to Feedback-Based Multiple Antenna 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: Research Article Analysis of Vector Quantizers Using Transformed Codebooks with Application to Feedback-Based Multiple Antenna Systems | Hindawi Publishing Corporation EURASIP Journal on Wireless Communications and Networking Volume 2008 Article ID 125892 13 pages doi 2008 125892 Research Article Analysis of Vector Quantizers Using Transformed Codebooks with Application to Feedback-Based Multiple Antenna Systems Jun Zheng and Bhaskar D. Rao Department of Electrical and Computer Engineering University of California San Diego La Jolla CA 92093-0407 USA Correspondence should be addressed to Jun Zheng juzheng@ Received 3 April 2007 Revised 8 February 2008 Accepted 2 March 2008 Recommended by Visa Koivunen Transformed codebooks are obtained by a transformation of a given codebook to best match the statistical environment at hand. The procedure though suboptimal has recently been suggested for feedback of channel state information CSI in multiple antenna systems with correlated channels because of their simplicity and effectiveness. In this paper we first consider the general distortion analysis of vector quantizers with transformed codebooks. Bounds on the average system distortion of this class of quantizers are provided. It exposes the effects of two kinds of suboptimality introduced by the transformed codebook namely the loss caused by suboptimal point density and the loss caused by mismatched Voronoi shape. We then focus our attention on the application of the proposed general framework to providing capacity analysis of a feedback-based MISO system over spatially correlated fading channels. In particular with capacity loss as an objective function upper and lower bounds on the average distortion of MISO systems with transformed codebooks are provided and compared to that of the optimal channel quantizers. The expressions are examined to provide interesting insights in the high and low SNR regime. Numerical and simulation results are presented which confirm the tightness of the distortion bounds. Copyright 2008 J. Zheng and B. D. Rao. This is an open access article distributed under .