交织子载波FBMC-IM水声通信系统的性能分析

Performance analysis of FBMC-ISIM underwater acoustic communication system

针对现有基于滤波器组多载波的索引调制(FBMC-IM)系统在水声通信中无法获得更优误码率性能的问题,对FBMC-IM系统进行改进,提出一种基于滤波器组多载波的交织子载波索引调制系统(FBMC-ISIM)。该技术继承了基于滤波器组多载波调制系统(FBMC)和索引调制系统的优势,利用子载波索引控制载波的激活,灵活地调整静默子载波数和激活子载波数,同时通过联合设计,使承载数据符号的实载波按照交织子载波索引调制的方式进行数据映射,从而使同一子块的子载波信道衰弱不相关,大大降低了系统的误码率。在实测水声信道下进行仿真,仿真结果显示该技术在相同信噪比下比FBMC-IM系统的误码率更低,证明了该技术在水声信道中可以获得比FBMC-IM系统更优的误码率性能。

Since the existing filter bank multicarrier based index modulation(FBMC-IM)system fails to obtain better bit error rate performance in the underwater acoustic communication,the FBMC-IM system is improved,and a filter bank multicarrier based interleaved subcarrier index modulation(FBMC-ISIM) system is proposed. This technology inherits the advantages of filter bank multicarrier(FBMC) modulation system and index modulation(IM) system. The subcarrier index is used to control the activation of the carriers. The numbers of silent subcarriers and activated subcarriers are adjusted flexibly. By joint design,the real carriers carrying data symbols are subjected to data mapping according to the ISIM mode,so that the channel fading of the subcarrier in the same sub-block is irrelevant,which greatly reduces the bit error rate(BER) of the system. Simulations were carried out on the measured underwater acoustic channels. The simulation results show that the bit error rate of the proposed technology is lower than that of the FBMC-IM system at the same signal-to-noise ratio(SNR).Therefore,it has been proved that the technology can achieve better BER performance than the FBMC-IM system in the underwater acoustic channels.