tailieunhanh - Báo cáo hóa học: "Optimal Training for Time-Selective Wireless Fading Channels Using Cutoff Rate"

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: Optimal Training for Time-Selective Wireless Fading Channels Using Cutoff Rate | Hindawi Publishing Corporation EURASIP Journal on Applied Signal Processing Volume 2006 Article ID 47245 Pages 1-15 DOI ASP 2006 47245 Optimal Training for Time-Selective Wireless Fading Channels Using Cutoff Rate Saswat Misra 1 2 Ananthram Swami 1 and Lang Tong2 1 The Army Research Laboratory Adelphi MD 20783 USA 2 Department of Electrical and Computer Engineering Cornell University Ithaca NY 14850 USA Received 1 June 2005 Revised 11 December 2005 Accepted 13 January 2006 We consider the optimal allocation of resources power and bandwidth between training and data transmissions for singleuser time-selective Rayleigh flat-fading channels under the cutoff rate criterion. The transmitter exploits statistical channel state information CSI in the form of the channel Doppler spectrum to embed pilot symbols into the transmission stream. At the receiver instantaneous though imperfect CSI is acquired through minimum mean-square estimation of the channel based on some set of pilot observations. We compute the ergodic cutoff rate for this scenario. Assuming estimator-based interleaving and M-PSK inputs we study two special cases in-depth. First we derive the optimal resource allocation for the Gauss-Markov correlation model. Next we validate and refine these insights by studying resource allocation for the Jakes model. Copyright 2006 Saswat Misra et al. This is an open access article distributed under the Creative Commons Attribution License which permits unrestricted use distribution and reproduction in any medium provided the original work is properly cited. 1. INTRODUCTION In wireless communications employing coherent detection imperfect knowledge of the fading channel state imposes limits on the achievable performance as measured by for example the mutual information the bit-error rate BER or the minimum mean-square error MMSE . Typically a fraction of system resources bandwidth and energy is devoted to channel estimation techniques known as training which .