Joint time-frequency domain equalization of MSK signal over underwater acoustic channel. (28th February 2022)

• Record Type: Journal Article
• Authors: Han, Ruigang; Jia, Ning; Huang, Jianchun; Guo, Shengming
• Is Part Of: Applied acoustics. Volume 189(2022)
• Publication Date: 2022-02-28
• Subjects: Underwater acoustic communication -- Minimum shift keying -- Block linear equalization -- Time-domain adaptive decision feedback equalization -- Joint time-frequency domain equalization; Acoustical engineering -- Periodicals; Periodicals; 620.2
• DOI: 10.1016/j.apacoust.2021.108597
• Languages: English
• ISSNs: 0003-682X

Abstract

Highlights: This paper attempts to apply MSK modulation to underwater acoustic channels to improve bandwidth utilization and power efficiency. The joint time–frequency domain equalization based on Laurent's decomposition is proposed to further reduce bit error rate and is verified by the sea trial. The joint time–frequency domain equalization combines the advantages of TD-ADFE tracking channel change and FD-BLE suppressing ISI which is caused by complex multipath fading channel. Abstract: Minimum shift keying (MSK) shows better bandwidth efficiency than the phase shift keying owing to its high bandwidth usage efficiency and constant envelope property. The performance of frequency-domain block linear equalization (FD-BLE), which is commonly used for MSK communication, is limited in complex time-varying underwater acoustic (UWA) channel. In this paper, a time-domain adaptive decision feedback equalization (TD-ADFE) is proposed to address issues pertaining to MSK communications over UWA channel. Further joint time–frequency domain equalization (JTFDE) built on TD-ADFE and BLE is proposed to further reduce the bit error rate (BER). The proposed method can effectively track the time-varying UWA channel through the updated equalizer coefficient according to the output of de-mapper. Numerical simulation shows that the JTFDE performed better than TD-ADFE and FD-BLE over time-varying UWA channel by approximately 2 dB when the BER was 1 × 10 −3 .The sea trial results verified the proposed JTFDE and demonstrated that the BER of JTFDE was 82.5% and 88.9% lower than that of TD-ADFE and FD-BLE, respectively.