基于LDPC译码软信息的迭代载波恢复

包建荣; 詹亚锋; 陆建华

doi:10.3724/SP.J.1146.2008.01321

基于LDPC译码软信息的迭代载波恢复

doi: 10.3724/SP.J.1146.2008.01321

包建荣^{①;詹亚锋},
詹亚锋,
陆建华

基金项目:

国家自然科学基金(60532070，60525107)和国家基础研究计划(2007CB310601)资助课题

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出版历程
- 收稿日期: 2008-10-14
- 修回日期: 2009-03-12
- 刊出日期: 2009-10-19

Iterative Carrier Recovery Based on Soft Decision Metrics of LDPC Decoding

摘要

摘要: 针对较低信噪比(2dB)下载波恢复难题，该文提出了基于LDPC软信息的迭代载波恢复算法。该算法以最大化LDPC软信息绝对值的和为准则，对载波频差用搜索窗辅助的单纯形算法进行搜索，得到较准确的载波估计并补偿。且它还采用LDPC软信息辅助的科斯塔斯环，来纠正残留载波偏差。仿真表明，它能有效纠正载波偏差及克服相位模糊、跳周等问题，并以一定计算复杂度的代价，获得距理想QPSK编码系统0.1以内的误码性能。
- LDPC码; 载波同步; 迭代载波恢复
Abstract: It is difficult to recovery carrier at rather low SNR (2 dB). An iterative carrier recovery via soft decision metrics of LDPC decoding is proposed. By maximizing the sum of the absolute value of the soft decision metrics of LDPC decoding with search window aided simplex algorithm, it can obtain accurate carrier estimate which will be compensated. Meanwhile, it can be combined with the Costas loop with LDPC decoding feedback to eliminate the residual carrier offsets. Simulation results indicate that it can overcome the problems of phase ambiguity, cycle slip and so on, and the performance of the QPSK system with it under carrier offsets is just within 0.1 dB of the ideal performance at the cost of some more computation complexity.

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参考文献(1)

MacKay D J. Good error-correcting codes based on verysparse matrices [J].IEEE Transactions on InformationTheory.1999, 45(2):399-431[2]Oh W and Cheun K. Joint decoding and carrier phaserecovery algorithm for turbo codes [J]. IEEE CommunicationLetters, 2001, 5(9): 375-377.[3]Zhang L and Burr A G. Iterative carrier recovery suited toturbo-coded systems [J]. IEEE Transactions on WirelessCommunications, 2004, 3(6): 2267-2276.[4]Lottici V and Luise M. Embedding carrier phase intoiterative decoding of turbo-coded linear modulations [J].IEEE Transactions on Communications.2004, 52(4):661-669[5]Valles E L, Wesel R D, Villasenor J D, and Jones C R. Carrierand timing synchronization of BPSK via LDPC codefeedback [C]. Proc. 40th Asilomar Confere, nce on Signal,System and Computers, Pacific Grove, CA, 2006: 2177-2181.[6]李茂沛, 周廷显. 改进科斯塔斯环的LDPC 码相位同步算法[J]. 哈尔滨工业大学学报, 2007, 39(11): 1764-1766, 1821.Li Mao-pei and Zhou Ting-xian. Iterative phasesynchronization algorithm based on modified Costas loop forLDPC coded systems [J]. Journal of Harbin Institute ofTechnology, 2007, 39(11): 1764-1766, 1821.[7]Mielczarek B and Svensson A. Timing error recovery inturbo-coded systems on AWGN channels [J].IEEETransactions on Communications.2002, 50(10):1584-1592[8][8] CCSDS. Low density parity check codes for use in near-earthand deep space [S]. Washington, DC, USA: the ConsultativeCommittee for Space Data Systems. 2007: (3-1)-(3-11).[9]Jeffrey C L, James A R, Margaret H W, and Paul E W.Convergence properties of the Nelder-Mead simplex methodin low dimensions [J].SIAM Journal of Optimization.1998,9(1):112-147[10]Choi K. Residual frequency offset compensation-embeddedturbo decoder [J]. IEEE Transactions on VehicularTechnology, 2008, 57(5): 3211-3217.

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