一种改进的基于子空间MIMO-OFDM信道盲估计算法

An Improved Blind Estimation Algorithm of MIMO-OFDM Channel Based on Subspace

信道估计是MIMO-OFDM系统的关键技术,相比非盲估计而言,盲估计技术具有带宽利用率高,系统传输效率高的优点。基于子空间盲估计算法在信道变化不是很快的情况下有比较精确的估计效果,但是多径衰落、噪声等会引起子空间之间的非正交,从而导致估计性能急剧恶化,本文采用斜投影解决子空间之间非正交问题,采用MMSE估计准则的仿真结果表明对信道估计性能有明显的提高。

Channel estimation is the key technology of MTMO-OFDM system, compared with non-blind estimation, blind estimation has higher bandwidth utilization and better transmission efficiency. Blind estimation ofsubspace has more accurate effect when channel changes slowly, but the multipath fading and noises will cause the non-orthogonal between subspaces which leads to estimation effect deteriorated sharply. This paper adopts oblique projection to solve the non-orthogonal problem of the subspace, and the simulation results of MMSE estimation criterion show that the performance of the channel estimation is obviously improved.