Performance analysis of underwater digital speech communication system based on LDPC codes

To reduce error codes between the receiver and the transmitter and to achieve credible transmission performance of underwater digital speech communication system, low density parity check code (LDPC) is introduced to underwater digital speech communication system. Based on the characteristics of the system, (864,432) LDPC code with code rate 1/2, row weight 6, column weight 3 is selected. We also compare the LDPC code with Turbo code with 1/2 code rate. The experiment results show that digital speech signal transmission is reliable if signal to noise is more than 1.5dB in the underwater digital speech communication system.