Evaluation of Low Density Parity Check Codes Over Various Channel Types


Low density parity check (LDPC) codes are one of the best error correctingcodes in today’s coding world and are known to approach the Shannon limit. Aswith all other channel coding schemes, LDPC codes add redundancy to theuncoded input data to make it more immune to channel impairments. In this paper,the impact of low-Density Parity-Check code (LDPC) on the performance ofsystem under Binary Phase Shift keying (BPSK) over an Additive White GaussianNoise (AWGN) and other fading (Raleigh and Rician) channels is investigated.Obtained results show that LDPC can improve transceiver system for variouschannel types. At Bit Error Rate (BER) of 10-4 such code with code rate of ½reduces the Signal to Noise Ratio (SNR) by range of 6.5 to 9 dB for fadingchannels in contrast to uncoded system. By studying modern research it has beenfound that turbo code can achieved same manner but LDPC decoder faster thanturbo decoder and can be implemented in parallel.


LDPC, BPSK, Rician, Rayleigh