Study On The Theory Of Network Coding And Its Application

Other than traditional multicast routing algorithms, the network information flow can approach the max-flow of multicast network by adopting network coding. So, coding is better than routing. The invention and development of network coding point out a new research field for information transmission. Combining the theoretic and practical fruits available, network coding can be applied to the existing communication technique to obtain better performance, which has inspired many attentions.In this dissertation, the theory of network coding and its application are studied. Several results are obtained. They are(1) The principles of network coding are systematically summarized. The exponent time algorithms and polynomial time algorithms are analyzed, and then the finite field required is given.(2) A multicast routing algorithm with network coding is presented. The reason that this algorithm can decrease resource consumption and improve load balance is systematically analyzed. To handling transmission errors of data link, a multicast routing algorithm based on XOR selective repeat ARQ is proposed.(3) Based on the characterizations of minimal subtree graphs, an algorithm to search minimal subtree graphs is presented. Then network coding can be effectively constructed in minimal subtree graphs, and all the network coding problems can be equivalent to search the minimal subtree graphs.(4) Using some results of maximum distance separable codes available, methods for constructing codes in k-redundant multicast network and multicast networks with link failure are respectively proposed. The minimal finite field which is enough to implement network coding for different multicast rate is obtained. In wireless sensor network, based on the linear combination method of network coding, an algorithm for faster data collection is presented.(5) For the network with two sources exchanging information through relay node, a physical-layer network coding method with constellation mapping is given. This method can reduce energy consumption in relay node without performance degradation.(6) The application of network coding in cooperative communication is analyzed. Then, an optimization design method for parallel relays in complex field network coding is proposed. This method can decrease the detection complexity of destination node and the transmission delay of source symbol.