Abstract:

In order to transport data efficiently and reliably without reducing the transmission rate of data, minimize the bit error rate and improve the system throughput,LDPC（Low-Density Parity-Check Code）are used as forward error correction code in HARQ（Hybrid Automatic Repeat Request） system, and it combined with ARQ(Automatic Repeat Request) technology. The ARQ scheme chooses SR-ARQ, namely selective request ARQ，it will choose the error data block to retransmission, and using type-I HARQ pattern to do request controlling. The model is built and system is designed on simulink.Combined Matlab modulation,the throughput of code with different length and different code rate is analyzed, and the results are shown by using ARQ scheme and without it，the results indicate that the system with ARQ scheme has better performance on throughput.

Key words: hybrid automatic repeat request(HARQ), low-density parity-check code(LDPC), bit error, rate throughput