FH-Sequence Change For Frequency-HOP HARQ Communication Systems Subject To Partial-Band Interference

HARQ (Hybrid Automatic Repeat reQuest) is a technology combining Forward Error Correction Coding (FEC) and Automatic Repeat reQuest (ARQ) protocol at the transmitter and receiver. If there is strong interference and wideband fading in the wireless channel, the throughput of the frequency hop spread spectrum (FHSS) communication system using the HARQ protocol may be unacceptably low. A novel frequency hopping sequence change scheme was proposed. In such a scheme, the length of the frequency hopping (FH) sequence and the number of frequency hopping points per packet are relatively prime numbers, which can ensure that the FH sequence is different for each retransmission, greatly adapting to the diversity and complexity of frequency band interference. Simulation and analysis results indicate that changing the FH sequence during each HARQ retransmission can significantly improve throughput when compared with the system without changing.