基于有限字符特性的空时OFDM系统决策反馈信道估计
doi: 10.3724/SP.J.1146.2006.01116
Finite-Alphabet and Decision-Feedback Based Channel Estimation for Space-Time Coded OFDM Systems
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摘要: 该文提出了一种适用于空时编码正交频分复用(STC-OFDM)系统盲信道估计算法，利用信号的字符有限特性获取粗信道估计，进而利用映射星座先验知识，采用决策反馈方法得到信道精估计。充分利用了信号的先验知识，以较高的计算复杂度为代价，提高了盲信道估计精度，因此能较好地适用于具有慢时变频率选择性较强的信道，且子载波数不大的系统。与基于子空间盲信道估计算法比较验证了该算法性能。Abstract: A novel blind channel estimation scheme is presented for Space-Time Coded OFDM (STC-OFDM) systems. This scheme is composed of rude channel estimation by exploiting the finite-alphabet property of information signals and fine channel estimation by using decision-directed method, which employs the priori knowledge of the transmitted signals other than the finite-alphabet property of mapping constellation. At the cost of a little more computational complexity, it achieves better performance than the competitive one, hence it is suitable for STC-OFDM systems with a small number of subcarriers in slowly time-varying and not severely frequency selective channels. The scheme is tested with simulations and also compared with the subspace-based channel estimation.
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Alamouti S M. A simple transmit diversity technique forwireless communications[J].IEEE Journal on Selected Areas inCommunications.1998, 16(8):1451-1458[2]Ye L, Nambirajan S, and Sirikiat A. Channel estimation forOFDM systems with transmitter diversity in mobile wirelesschannels[J].IEEE Journal on Selected Areas inCommunications.1999, 17(3):461-471[3]Yantao Q, Songyu Y, Pengcheng S, and Lijun Z. Research onan iterative algorithm of LS channel estimation in MIMOOFDM systems[J].IEEE Trans. on Broadcasting.2005, 51(1):149-153[4]Zhou S, Bertrand M, and Giannakis G B. Subspaced-based(semi-) blind channel estimation for block precodedspace-time OFDM[J].IEEE Trans. on Signal Processing.2002,50(5):1215-1228[5]Zhiqiang L, Georgios B G, Sergio B, and Anna S.Transmit-antennae space.-time block coding for generalizedOFDM in the presence of unknown Multipath. IEEE Journalon Selected Areas in Communications, 2001, 19(7): 1352-1363.[6]Zeng Y, Lam W H, and Ng T S. Semi-blind channelestimation and equalization for MIMO space-time codedOFDM. IEEE Trans. on Circuits and Systems, 2006, 53(2):463-474.[7]Shengli Z, Georgios B G, and Anna S. Long codes forgeneralized FH-OFDMA through unknown multipathchannels[J].IEEE Trans. on Communications.2001, 49(4):721-733 -
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