Application Research On The Multi-user Cooperative Network Coding

Giving the full play advantage of cooperative network coding to improve networkthroughout and frequency utilization, along with the effective combination ofcooperative communication and network coding in the actual wireless communicationenvironments, is one of the most popular research topics in the new generation wirelesscommunications. Thereby, the thesis emphasizes on some issues of physical layernetwork coding in the multi-user communications by introducing the performanceevaluation of bit error rate and outage probability.The detailed research is as follows:1. Due to most researchers mainly focusing on coding algorithms and performanceevaluation and application scheme for network coding, a physical layer network codingscheme realized by symbol mapping is proposed in the thesis, and the impact of themodulation and power allocation on bit error rate and outage probability is alsocomparatively analyzed. Studies show that the outage performance of physical layernetwork coding based on symbol mapping outperforms other typical transmissiontechniques.2. Due to the most network coding research based on the two-user relaycooperative networks, the outage probability performance of finite field network codingand complex field network coding in multi-user cooperative networks is studied. Studiesshow that the complex field network coding scheme can further decrease the outageprobability and improve the reliability of link transmission comparing to the othercooperative transmission schemes.3. A network coding algorithm based on orthogonal process is proposed, whichemploys orthogonal low frequency signals to implement orthonormalization,accordingly the relay node can avoid the mutual interference between different usersand detect the simultaneous multi-userstransmitted signals and decode the user signalby an inverse orthogonal process. Theoretical analysis shows that the proposedalgorithm can reduce transmission delay, and the computer simulations also show thatthe proposed algorithm can improve bit error rate and outage probability performance.