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Báo cáo hóa học: " Research Article Maximum Likelihood Timing and Carrier Synchronization in Burst-Mode Satellite Transmissions"

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 Maximum Likelihood Timing and Carrier Synchronization in Burst-Mode Satellite Transmissions | Hindawi Publishing Corporation EURASIP Journal on Wireless Communications and Networking Volume 2007 Article ID 65058 8 pages doi 10.1155 2007 65058 Research Article Maximum Likelihood Timing and Carrier Synchronization in Burst-Mode Satellite Transmissions Michele Morelli and Antonio A. D Amico Department of Information Engineering Via Caruso 56100 Pisa Italy Received 4 August 2006 Revised 2 March 2007 Accepted 13 May 2007 Recommended by Alessandro Vanelli-Coralli This paper investigates the joint maximum likelihood ML estimation of the carrier frequency offset timing error and carrier phase in burst-mode satellite transmissions over an AWGN channel. The synchronization process is assisted by a training sequence appended in front of each burst and composed of alternating binary symbols. The use of this particular pilot pattern results into an estimation algorithm of affordable complexity that operates in a decoupled fashion. In particular the frequency offset is measured first and independently of the other parameters. Timing and phase estimates are subsequently computed through simple closed-form expressions. The performance of the proposed scheme is investigated by computer simulation and compared with Cramer-Rao bounds. It turns out that the estimation accuracy is very close to the theoretical limits up to relatively low signal-to-noise ratios. This makes the algorithm well suited for turbo-coded transmissions operating near the Shannon limit. Copyright 2007 M. Morelli and A. A. D Amico. 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 Burst transmission of digital data and voice is widely adopted in satellite time-division multiple-access TDMA networks. In these applications the propagation medium can be reasonably modeled as an additive white Gaussian noise AWGN channel and knowledge