Efficient Decoding of Low-Density Parity Check Codes

Low Density Parity Check Codes ( LDPC ) are a type of linear-block LDPC codes which play a Prominent role in Error detection and Correction Techniques. They are Various methods for Decoding LDPC Codes. Two Prominent methods of Decoding LDPC Codes are Hard decision method and Soft Decision Method. Even though the Hard decision decoding algorithm is computationally simple, its BER performance is not appreciable. Devising soft decision decoding algorithms which are simple and good in BER performance. Quadrature Phase Shift Keying (QPSK) modulation is done and the AWGN noise is introduced to the modulated code word. This paper compares the Bit Error Rate (BER) performance of soft and hard decision decoding algorithms of LDPC codes on AWGN channel at different code rates and Modulation Order(M). The analysis is conducted in MATLAB.