LDPC decoder performance under different number of iterations in mobile WiMax

We investigate low-density parity-check (LDPC) codes performance used in the IEEE 802.16e under different number of iterations. We use min sum algorithm and sum product algorithm to decode the LDPC codes in various modulation schemes. Simulations are done in Rayleigh channel. From our simulations, we can get better improvement in term of bit error rate (BER) when we increase the iterations from 5 to 10. When we increase the iterations further, we observe slight improvement in BER. Later, we also discuss the simulation results when using sum-product algorithm and min-sum algorithm.