Performance investigation of hybrid ARQ in HSDPA systems with AMC

In the world of telecommunication, demand for 3G mobile communication services still dominates the global market. It continues to grow despite the introduction of new technologies such as LTE and LTE-A. Hybrid Automatic Repeat Request (HARQ) and Adaptive modulation and coding (AMC) are among the key performance enhancing techniques adopted in High Speed downlink packet access (HSDPA). Limiting the maximum number of HARQ retransmissions in downlink is important to save the radio resources. In this paper, we investigate the throughput and error performance of HSDPA systems employing HARQ and AMC, for different mobile receiver speeds. Furthermore, the impact of turbo equalization on the performance is also investigated. A method to obtain the optimal value for the maximum number of HARQ retransmissions in HSDPA is proposed.