Modified Aggressive Packet Combining Scheme with Repetition Code for Throughput Enhancement in High Error Rate Channel

Abstract

Aggressive packet combining (APC) scheme is a well-established scheme which reduces the number of retransmissions for receiving correct packet in error prone wireless link. It is a well-known fact that the retransmissions consume extra bandwidth and battery energy of the portable computer. Therefore, APC is an efficient technique which reduces number of retransmissions for a packet, thus reducing latency of the wireless system. In APC, three copies of a packet are transmitted, and receiver does bit-wise majority decision to get the combined copy. Least reliable bits identification is done in the combined packet if majority logic fails. Search the correct bit pattern for least reliable bits so obtained. APC provides higher reliability but at expense of throughput of the system. Therefore, major issue in APC is the lower throughput which at maximum is 33.33% ($\frac{1}{3} \times 100$). In this paper, modified APC with repetition code is proposed which addresses lower throughput issue of conventional APC. Simulation results show significant performance improvement in terms of throughput when packet combining scheme with repetition code is used in APC scheme.