A wavelet coding scheme used in Multi-Source Relay-Based Cooperative Communication

The Multi-Source Relay-Based Cooperative Communication (MRBCC) is widely used to improve the channel reliability. Recently, there are two major Network Coding (NC) methods proposed for MRBCC. One is the Galois Fields NC (GFNC) which implements the NC scheme by randomly choosing encoding vectors from a high order Galois field. The other is the Complex Field NC (CFNC) where the author proposes an approach by mapping packets to orthogonal sinusoidal waves therefore to transmit the symbol level data simultaneously. Unlike the above two methods, in this paper, we propose a Wavelet Network Coding (WNC) scheme to achieve the NC purpose. Not only does the new scheme solve the problem of wireless throughput limitation of GFNC, but also it conquers Inter-Symbol Interference (ISI) issues caused by CFNC. Moreover, thanks to the property of a wavelet transform, we can easily group the symbols by the frequency-time domain analysis base on the symbol´s priority, then determine whether to use redundant correction or not - if not, the transmission of source-to-relay and relay-to-sink can be paused and sub-channels allocated to the relay can be released. Through this way, a flexible resource-saving scheme in MRBCC is achieved.