多相分解滤波器在OFDM高速水声通信中的应用

影响OFDM浅海高速水声通信的一个重要的因素是多普勒,多普勒频率会导致OFDM子载波间的正交性被破坏,进而带来OFDM子载波间干扰,严重影响OFDM水声通信的质量,因此必须对如何消除多普勒进行研究。在水声通信中消除多普勒的影响通常分两步：首先对多普勒因子正确估计,进而对接收数据变采样。在仿真实现变采样的基础上,利用多相分解降低其运算量,实现了高速率的变采样滤波器,并将算法运用到OFDM系统仿真中,最终对OFDM湖试数据进行解码,取得了满意的结果,很大程度上降低了多普勒频移对OFDM水声通信系统的影响。

Appliciation of polyphase decomposition filter in high-speed underwater acoustic OFDM communication

Doppler is one of the most important factors which affects the high-speed underwater acoustic OFDM communication in shallow water.Doppler frequency shift could lead the orthogonalilty between sub-carriers of OFDM damaged and the quality of the OFDM communication system degraded.So it is urgent to conduct a study of how to eliminate the Doppler.There are usually two steps to eliminate the impact of Doppler on underwater acoustic communication： first estimate the Doppler factor,and then resample the received data.Based on simulation,this paper firstly achieves resampling,then uses ployphase decomposition for reducing the computational complexity to form a high rate of variable resampling filter and applies the algorithm to the OFDM system simulation,finally processes the lake test data.The effect of Doppler shift on the underwater acoustic OFDM communication system is greatly reduced and satisfactory results are obtained in this paper.