基于双层符号常数模的多径水声信道盲均衡算法

A Multipath Underwater Acoustic Channel Blind Equalizer Based on Double Sign Constant Modulus Algorithm

针对常数模算法(CMA)及符号常数模算法(SCMA)迭代中的大量乘法运算会产生延时的不足,提出了双层符号常数模算法(DSCMA)。该算法采用逐级取符号的办法,将迭代过程中的大量乘法运算转化为比较运算,大大减少了计算量。而基于双层符号常数模的多径水声信道盲均衡器,具有收敛速度快,超量均方误差和计算复杂度小等特点。用负声速梯度信道及深海信道对该盲均衡器性能进行的仿真研究表明:该盲均衡器对多径干扰有良好的抑制作用,对水下数据通信有很强的实用价值。

For greatly reducing computational load of traditional constant modulus algorithm (CMA) or sign constant modulus algorithm (SCMA), double sign constant modulus algorithm (DSCMA) is developed and its structure is analyzed. The developed algorithm has turned multiplication operation in iteration process into comparison operation via extracting the hierarchical sign of iteration factors and its computational complexity is much smaller than that of the CMA or SCMA. The DSCMA-based multipath underwater acoustic channel blind equalizer has many features such as fast convergence, low excess mean square error and low computational complexity, etc. The proposed blind equalizer is simulated using negative sound speed gradient channel and deepwater channel. The result has shown that the blind equalizer can effectively overcome the multipath interference of underwater acoustic channel.