Research of FH-MFSK Underwater Acoustic Communication Based on Non-Binary LDPC Codes

• Published in: Applied Mechanics and Materials Vol. 519-520; no. Computer and Information Technology; pp. 945 - 952
• Main Authors: Li, Bo, Zhang, You Wen, Fan, Wei Wei, Sun, Da Jun
• Format: Journal Article
• Language: English
• Published: Zurich Trans Tech Publications Ltd 01.02.2014
• Subjects: Binary codes; Channels; Error correcting codes; Mathematical models; Modulation; Symbols; Synchronism; Underwater acoustics; FH-MFSK; Non-Binary LDPC Code; Underwater Acoustic Communication
• ISBN: 3038350192; 9783038350194
• ISSN: 1660-9336; 1662-7482; 1662-7482
• DOI: 10.4028/www.scientific.net/AMM.519-520.945

Compared with binary-modulation, Multiple-modulation can obtain higher rate of transmission in the condition of same symbol-rate. If using binary channel codes with multiple-modulation, there exists an problem of information-loss of the probability from bit to symbol conversion. Underwater acoustic channel is an multipath, time-variation, high-noise and strong doppler-effect wireless channel, which leads to high error-rate caused by signal distortion. To solve the problems above, we adopt FH-MFSK modulation to overcome the inter-symbol interference by multipath. The PN sequence is used as a frame synchronization signal and frequency energy accumulation method is used to detect the frame-synchronization. PN hopping signal is chosen to estimate the doppler frequency-shift and using non-binary LDPC codes based on symbol for channel error codes. Finally, We perform numerical simulations and the experiments on the lake to show that compared with binary LDPC codes, non-binary LDPC codes for multiple-modulation can achieve same error-rate under lower SNR.