【摘要】 针对多输入多输出(MIMO)正交频分复用(OFDM)系统中部分编码速率小于1的正交空时分组码(OSTBC),在不添加外部冗余而仅利用空时分组编码自身冗余和正交性的情况下给出了一种基于噪声空间的盲信道估计方法.在OSTBC OFDM信号模型的基础上通过奇异值分解(SVD)方法求解信道的噪声空间,得到一组信道响应,并使用少量导频确定信道估计结果的模糊度,讨论了噪声空间可分解的条件.提出了通过减小SVD操作对象维度来降低运算量的几种考虑,利用计算机仿真给出了该估计方法在不同条件下的归一化均方误差和误符号率性能.更多还原

【Abstract】 A blind channel estimation technique based on noise space for multiple-input multiple-output(MIMO) orthogonal frequency division multiplexing(OFDM) systems was presented.The method can be applied to some kinds of orthogonal space-time block code(OSTBC) with coding rate smaller than 1 and utilizes only the orthogonality and redundancy introduced by themselves.The singular value decomposition(SVD) method was used to get the noise space and channel impulse responses(CIRs) with ambiguity which was resolved by some pilots.Conditions for the existence of noise space decomposition were discussed.Some considerations were proposed to reduce computational complexity by decreasing the dimension of the objects of SVD.Numerical results illustrate the mean-square error performance and symbol error rate of the method.更多还原