The Study of Low-Delay Incremental Redundancy Hybrid ARQ Schemes in Adaptive Modulation System
自适应调制混合ARQ系统中低时延冗余递增策略的研究

The incremental redundancy hybrid ARQ scheme can provide high throughput efficiency. Meanwhile, it also leads to high transmission delay. This paper presents a Low-Delay Incremental Redundancy hybrid ARQ scheme with Adaptive Modulation (AM-LD-IR). It adopts different strategy of incremental redundancy and constellation size according to the received Signal-to-Noise Ratio (SNR). The calculation and simulation results in the paper show, comparing to the ordinary incremental redundancy hybrid ARQ systems with adaptive modulation, the AM-LD-IR system can provide a little higher throughput efficiency and can reduce much transmission delay.