一种改进的时变SIMO信道常模盲均衡算法

Improved CM-Based Blind Equalization Algorithm of Time-Varying SIMO Channel

为了提高时变(Time-varying,TV)信道的盲均衡性能,利用信源符号的常模(Constant modulus,CM)特性,针对单位圆附近含有公共零点的非理想信道,首先证明时变多天线联合接收(Single input multiple output,SIMO)盲均衡器与信道矩阵的联合冲激响应包含多个非零抽头,进而提出一种改进的基频率估计方法,克服了传统时变信道盲均衡器对于理想信道的局限性,并通过引入递归最小二乘常模算法以提高均衡器的收敛性能。仿真实验结果表明,改进方法提高了盲均衡器的收敛速度,拓宽了时变SIMO信道盲均衡结构的适用范围,能够更好地实现时变信道的盲均衡。

To improve the blind equalization performance of the time-varying （TV） channel, the constant modulus （CM） property of source signals is exploited. For the TV single-input multiple-output （SIMO） channel whose common zeros are close to the unit circle, it is demonstrated that there are more than one taps of the combined impulse response. Then an improved frequency estimation method is proposed to overcome the limitations of the traditional means. To miprove the convergence performance, the recur- sive least mean square constant modulus algorithm （RLS-CMA） is introduced. Simulation results dem- onstrate that the proposed algorithms can effectively improve the performance and it can be widely used for blind equalization of the TV SIMO channel.