Research On Relay Forwarding Strategies Based On Distributed Fountain Codes In Wireless Body Area Network

With the growing concern about health,wireless body area network(WBAN)has emerged,providing people with a simple,low-cost means of health monitoring.The wireless body area network has limited energy,variable channels,and has high requirements for data transmission schemes.The data transmission scheme based on the distributed fountain code can meet the transmission requirements.The fountain code has no fixed code rate and can be flexibly adapted to variable channels.The distributed transmission scheme adopts a suitable forwarding strategy at the relay node,which can reduce the number of code symbols that the source node sends when decoding is successful,thereby reducing the power consumption.At the same time,the existing distributed fountain code transmission schemes are mostly based on the research of two sources,but the multiple source situation is more common in the wireless body area network.At the same time,channels of the wireless body area network are variable,requiring a flexible and adaptive transmission scheme.Therefore,targeting at the above two problems,this paper mainly focuses on relay forwarding strategy based on distributed fountain codes in wireless body area network.The main contributions are as follows:Firstly,this paper proposes a multi-source relay forwarding scheme and parameter optimization algorithm based on distributed fountain code in wireless body area network.The scheme simplifies the relay forwarding model of multiple source,and uses the differential evolution algorithm to optimize the selection probability of multiple sources,so that the source node sends minimized code symbols under the premise of achieving the expected symbol error rate.The simulation results show that the scheme can efficiently optimize the multi-source relay forwarding parameters.Compared with the randomly selected selection probability,when the relay node adopts the optimized selection probability,the number of code symbols that the source node needs to transmit is significantly reduced.Secondly,this paper proposes an adaptive transmission scheme with variable step size based on distributed fountain code in wireless body area network.The scheme is based on the characteristics of the wireless body area network channel.On the premise of successful decoding at the destination node,the relay node adjusts the forwarding parameters based on the number of received code symbols.Use a larger step size at the beginning of the adjustment and then gradually decrease it.The simulation shows that the channel is degraded and the number of received code symbols is significantly increased to achieve a certainrecovery rate,the adaptive transmission scheme with variable step size can make the system adapt to the variable channel with higher energy efficiency.