基于RCPC码和分块传输的新型HARQ系统

New HARQ System Based on RCPC and Sub-packet Transmission

在研究Ⅱ,Ⅲ型HARQ的基础上,提出了基于RCPC码的新型HARQ,并通过仿真得出不同信噪比下的最佳分块方案,以便使新型HARQ获得最佳性能。新型HARQ是将F个相同的分块穿孔后同时发送;在接收端,解穿孔后相同的分块进行分集合并。新型HARQ具有Ⅱ,Ⅲ型HARQ的优点,当信噪比较低时新型HARQ的通过率和平均重传次数接近于Ⅲ型HARQ;当信噪比较高时新型HARQ的通过率和平均重传次数接近于Ⅱ型HARQ。对Ⅱ,Ⅲ型和新型HARQ的性能进行理论分析和仿真,结果证明本文结论正确。

Based on the type-Ⅱ and type-Ⅲ Hybrid Automatic Repeat reQuest （HARQ） system and Rata Compatible Punctured Convolutional （RCPC） code, a new HARQ system is proposed in which F sub-packets could be transmitted in one data packet, at receiver the same F sub-packets are combined with each other to form a reliable packet equal to the punctured combined sequence after F retransmission. The optimal number of repeat sub-packets is obtained to improve the performance of new HARQ system. The new HARQ system has the advantages of type- Ⅱ and type-Ⅲ HARQ system, When the type-ⅡHARQ has higher throughput than the type-Ⅲ HARQ at higher Signal to Noise Ratio （SNR）, the throughput and the retransmission times of the new system is close to type-Ⅱ HARQ. The new HARQ system spares the redundancy bits, whereas the type-Ⅲ HARQ retransmits too much redundancy at high SNR. On the other hand when the type-Ⅲ HARQ has higher throughput than the type- Ⅱ HARQ at lower SNR, the throughput and average retransmission times are close to that of the type-Ⅲ HARQ. Unlike the too much retransmission times of type- Ⅱ HARQ in the low SNR, the new HARQ spare the number of retransmission times.