混合自动重传请求用于下行速率分裂多址 (Hybrid Automatic Repeat Request for Downlink Rate-Splitting Multiple Access)

This work investigates the design of Hybrid Automatic Repeat Request (HARQ) strategies for downlink Rate-Splitting Multiple Access (RSMA). The existence of private and common stream as well as their conditioning for Successive Interference Cancellation (SIC), gives rise to an expanded set of opportunities for retransmission of failed packets. Specifically, we devise a scheme in which the retransmissions are scheduled through the common stream, which offers a higher success probability. With this, the common stream needs to carry both new and retransmitted bits, which leads to a layered HARQ (L-HARQ) strategy which is capable of trading off throughput and reliability. Simulation results demonstrate that the devised HARQ scheme outperforms RSMA with conventional HARQ, where each retransmission is handled independently through its own stream. It also helps in closing the throughput gap between HARQ and Adaptive Modulation and Coding (AMC) in the high SNR regime while also achieving a decreased Packet Error Rate (PER) and a lower latency.

翻译：本文研究了混合自动重传请求（HARQ）策略在下行速率分裂多址（RSMA）中的设计。私有流和公共流以及它们的条件为连续干扰消除（SIC）提供了更多的重传失败分组的机会。具体而言，我们设计了一种方案，其中重传通过公共流进行调度，这提供了更高的成功概率。由此，公共流需要携带新的和重传的位，从而导致了分层HARQ（L-HARQ）策略。该策略能够在吞吐量和可靠性之间进行权衡。仿真结果表明，设计的HARQ方案优于具有传统HARQ的RSMA，其中每个重传通过自己的流独立处理。在高SNR水平上，它还有助于缩小HARQ和自适应调制和编码（AMC）的吞吐量差距，同时实现降低分组误码率（PER）和更低的延迟。