基于QAM星座图划分的水声信道多模算法

Underwater Acoustic Channel Multi-Mode Algorithm Based on Division of QAM Constellation

针对水声信道中存在较高码间干扰的问题,提出一种采用信号星座图划分的水声信道多模算法,根据水声信道中信噪比较低及QAM星座图的分布特点,进行详细的区域划分,以得到更多的信号星座点信息,对不同的区域定义了不同的模值进行均衡,能够有效降低码间干扰,纠正相位旋转,提高均衡效果。在水声信道条件下,采用QAM调制信号对算法的收敛性能和载波恢复性能进行计算机仿真,结果表明,在最小相位水声信道环境中,新算法在码间干扰性能上得到很大改善;在具有相位旋转的信道环境中,新算法实现了对相位旋转的有效补偿,提高了水声通信数据的可靠性。

According to the blind equalization algorithm,a new underwater acoustic channel multi-mode algorithm based on constellation division was proposed.According to the low Signal to Noise Ratio in underwater acoustic channel and the QAM signal constellation＇s characteristic,the new algorithm divides the constellation in detail in order to get more information about signal constellation,and uses different modulus to balance signals in different areas,which can reduce the ISI,correct phase rotation and improve the effect of equalization.In the underwater acoustic channel,computer simulations were made based on convergence and carrier recovery performance of new algorithm which makes use of QAM signals.The simulation results prove that the new algorithm has greatly improved the ISI performance in the smallest phase underwater acoustic channel; and has corrected the phase rotation in a phase rotation channel,which improves the reliability of the data in the underwater acoustic communication.