Outage Capacity of Two-Way Relay Systems by Network Coding under Rayleigh Fading Channels

Networking coding is investigated to improve the throughput of wireless networks without additional resources used. Most of the previous research work focus on the AWGN channel. However, the radio signal is subject to severe fading over wireless channel. In this paper, the network coding outage capacity of two-way system under Rayleigh fading channel is studied by considering all the transmission stages. The system model is established through deriving the outage probability. In order to obtain the maximal outage capacity, the feasible region searching is used to solve this optimization problem. It is shown that the outage capacity is improved significantly by network coding through the numerical results. Regardless of various channel parameters, the best time allocated to network coding stage occupies about one third of the total period. The maximal outage capacity would be achieved through allocating the transmission data rate and time of each stage appropriately.