Network Coding in Wireless Communications
This chapter deals with Network Coding (NC) in general and with its application to wireless communications in particular. A short overview of Network Coding in wired and wireless communications is given in section 8.1. Section 8.2, NC describes methods in uplink wireless communications. In section 8.3 the advantage of nonbinary network codes over binary network codes is shown in a multiuser cooperative communication and multirelay scenarios. The application of (NC) to broadcast scenarios is then described. Finally, NC trends in wireless communications are given in section 8.5.
8.1 An Overview of Network Coding
In a classical network, data streams originating from a source and intended to a desired destination are routed through intermediate nodes before reaching their final destination. Those intermediate nodes, also called routers, simply route and/or replicate each data stream within the network.
By contract, NC manipulates those data streams at an intermediate node by combining the data from the streams before forwarding it to the destination. NC should not be confused with any kind of source or channel coding in a network executed over a single data stream at an intermediate node.
In order to illustrate the idea of NC, the butterfly example is shown in Figure 8.1 where a communication network is represented by a directed graph. In Figure 8.1, S is a source node transmitting ...