面向OFDM-MFSK水声通信的差错控制方法

Error control method for OFDM-MFSK underwater acoustic communication

多进制频移键控正交频分复用(orthogonal frequency division multiplexing multiple frequency shift keying,OFDM-MFSK)调制能抵抗水声信道中的多径衰落和多普勒效应,且无需复杂的信道估计与均衡,适合低成本的水声通信机设计。针对OFDM-MFSK水声通信系统,提出了一种差错控制编码方法,具体思想为在使用OFDM-MFSK传输原数据的同时调制子载波的相位以传输另一路编码,接收端结合两种解调方式,利用编码的差错图样与校验码实现数据的纠错。相比于其他前向纠错编码,此种差错控制方法的码长短、编解码复杂度低,结合OFDM-MFSK调制,能在保证通信可靠性和实时性的同时降低水声通信系统的实现成本,适用于低速率水声通信系统的设计。

Orthogonal frequency division multiplexing multiple frequency shift keying(OFDM-MFSK)is a promising modulation mode in low cost underwater acoustic(UWA)communication for its ability of resisting multipath fading Doppler effect without introducing channel estimation and equalization.In this paper,an error control method for OFDM-MFSK underwater communication system is introduced which allows the transmitter to send extra redundant codes by phase shift keying modulation.The receiver calculates the error pattern and check code to correct information sequences correspondingly.Compared with other forward error correction codes,the error control method in this paper has lower computational complexity.By combining the OFDM-MFSK system,it can also highly reduce the implementation cost of underwater acoustic communication system while ensuring communication reliability and real-time performance,which is applicable for the design of low-rate underwater acoustic communication equipment.