RANDOM NETWORK CODING IN ORTHOGONAL FREQUENCY DIVISION MULTIPLE ACCESS (OFDMA) NETWORKS USING CONTROL SIGNALING

摘要

This invention is related to a two-way cooperative communication system, method and apparatus to improve spectral and energy efficiency using Control Signal. The system applies random network coding (RNC), cooperative communication and OFDMA-techniques for the high performance. Multiple transmitters transmit data in two phases: (i) The broadcast phase with all transmitting nodes utilizing pre-assigned OFDMA subcarriers, determining their transmit power values and bit rates, and transmitting multiple symbols and (ii) The relaying phase that contains multiple pre-selected relay nodes first estimating multiple transmitted symbols by the source nodes and then performing network coding on the estimated symbols to generate their signals to be transmitted. Multiple receivers receive data using a Detector, which works in conjunction with a Network Decoding block such that they obtain distinct versions of the source nodes' symbols. A Relay- Selection module selects relays to improve performance, based on inputs from a performance monitoring and optimization block within the centralized control strategy. The network coding has the potential to address the ever increasing number of users and devices in cellular networks.