Performance of Low-Density Parity-Check (LDPC) Coded OFDM system based on Adaptive Power Allocation Algorithm

A LDPC-COFDM system model based on adaptive algorithm can allocate transmit power and bits among sub-carriers according to the channel gain of each sub-channel. An adaptive power allocation algorithm, which is beneficial for log likelihood ratio decoding of LDPC coded modulation, is proposed in this paper. The simulation results show that the model can effectively improve the bit-error-rate (BER) performance of the system, compared with the traditional OFDM system based on equal power allocation, adapting to the time-variant behavior of the multi-path fading channel.