As a result of the characteristics of UnderWater Acoustic(UWA)channel,such as rapid fading of Channel Frequency Response(CFR)due to large delay spreading,the development of UnderWater Acoustic Communication(UWAC)technology is challenged.The acquisition of effective and reliable Channel State Information(CSI)at the transmitter is a prerequisite for adaptive communication.To meet the needs of UWA adaptive OFDM communication,a CSI-Grouping-Sequencing-Fitting-Feedback(CSI-GSFF)based on sequenced codebook algorithm is proposed,which consists of three steps,including grouping,sequencing,and data fitting.Firstly,adjacent pilot subcarriers are divided into several groups and each group is seen as a feedback cell.Then,the pilot subcarriers within each group are sorted according to the channel gains to mitigate adverse effects such as high feedback overhead caused by the rapid fading of CFR.Finally,polynomial fitting is performed,and the sorting operation effectively reduces the fitting order.Through the simulation of time-varying channel data in sea trials,the results show that the CSI-GSFF algorithm can achieve the Bit Error Rate(BER)performance of the UWA adaptive OFDM communication system under the perfect CSI,while effectively reduce the feedback overhead.
关键词
水声通信/正交频分复用/自适应调制/信道状态信息/有限反馈
Key words
UnderWater Acoustic Communication(UWAC)/Orthogonal Frequency Division Multiplexing(OFDM)/Adaptive modulation/Channel State Information(CSI)/Limited feedback
维普
万方数据