An Error Bound Based HARQ for HSDPA System

In this paper, we compare the throughput performance of several conventional HARQ protocols and propose an error bound based HARQ. In the proposed method, the number of bits of retransmission is determined by the BER required after decoding. In other words, the bits number on each retransmission is not fixed and can be varied according to SNR of the received signal and the ability of channel coding. Simulations have been carried out under the multipath Rayleigh fading channel with different Doppler shifts. Although the proposed method increases the traffic amount of the uplink channel, yet, results show that the proposed method can further improve the throughput compared with the conventional CC and IR HARQ methods for the HSDPA system.