A wireless broadcast retransmission scheme based on random network  coding and its performance analysis

A broadcast retransmission scheme based on the random network coding is put forward for the wireless broadcast system to conquer the deficiency of the ARQ scheme.In broadcast node,all lost packets are combined with the random linear codes for retransmission.In received nodes,original data can be obtained after enough combined packets are received and decoded.The proposed scheme can effectively reduce the number of retransmission as well as improve the throughput of broadcast system.Based on the Gilbert-Elliott channel model,a multi-state Markov model is generated by uniting the channel state with the reception mode of received nodes.The closed-form expressions are derived for the throughput of RNC-ARQ.Finally,NS-2 simulator is used to evaluate the performance of the propsed scheme.The results show that the proposed RNC-ARQ scheme is better than the SR-ARQ and XOR-ARQ scheme in terms of the throughput.