改进的自适应最优低秩信道估计算法

针对正交频分复用系统中线性最小均方误差(LMMSE)信道估计算法计算复杂度高,且存在当信道的统计特性与先验知识不匹配时估计性能恶化的问题,利用信道频域冲激响应的移动平均自相关函数,结合子空间分解、跟踪和序列正交原理,提出一种改进的自适应最优低秩信道估计算法.对比文中算法和LMMSE算法、LS算法和联合AIC(akaike criterion)秩估计准则的自适应低秩信道估计算法,结果表明:文中算法的秩估计更为精确;在插入导频数量较少的情况下,改进的信道估计算法能获得更高的信噪比性能增益.

Improved Adaptive Optimal Low-Rank Channel Estimation Algorithm

Aiming at the problems of high computational complexity and estimation performance deteriorating when the statistical characteristics and prior knowledge of channel are mismatch of linear minimun mean square error channel estimation algorithm(LMMSE)in the orthogonal frequency division multiplexing system(OFDM), an improved adaptive channel estimation algorithm jointing channel rank estimation has been proposed, in which the moving-average channel correlation matrix, subspace decomposition, tracking and principle of orthogonal sequence are employed. Simulation results show that compared to different channel estimation algorithms including LMMSE, Least Sqrare channel estimation algorithm(LS), adaptive channel estimation joint akaike criterion(AIC)channel rank estimation(LRA-AIC)in frequency selective time varying channel, the proposed scheme has the best bit error rate performance and rank estimation is more accurate, and the proposed channel estimation can achieve higher R_SN performance gain under a less number of inserted pilots, thus solving the problems of high complexity of channel estimation algorithm.