Research On Network Coding For MIMO

Network coding has the advantage of increasing the network's transmission capacity, promoting the network's throughput, and enhancing the network's robustness. The basic principle of network coding is using linear or nonlinear process on the network nodes when receiving multi-channel data. The destination gets the information by using certain method after it received the signals from the relays. Adopting network coding in wireless relay networks, one of the research hotpots in recent times, can improve the network's bit error rate (BER) performance effectively and improve the networks'throughput without reducing the diversity gain.This thesis mainly studies the space-time coding method in wireless relay network which can improve the system's throughput and performance. Firstly, we outline the development history of MIMO and network coding and discuss the coding and decoding algorithms including the Alamouti codes and space-time block codes. Secondly, we describe several existing network coding techniques, including physical layer network coding and complex field network coding. Finally we proposed two network space-time coding technology: space-time coding technique based on the relays and improved network space-time coding techniques. The latter can achieve better throughput than the former.The space-time network coding combines wireless relay system model and complex field network coding, with the multi-antenna relay using space-time network coding and decode-forward strategy. This new strategy can not only improve the system performance, but also achieve better throughput.The improved space-time network coding strategy use XOR operation before the relays'network space-time coding to reduce the time slots and improve the throughput of the system. Compared with the conventional wireless communication system, this improved version of space-time network coding can improve the diversity gain of the system, so the performance of the communication system was also improved.