An Adaptive Network Convolutional Coding for Cooperative Relaying

In the wireless fading channel environment, cooperative relaying is an effective way to increase additional diversity gain, and network coding can be used to increase network throughput. Network coding uses XOR (exclusive or) to mix packets from two different sources, its robustness is low and each relay can only service two sources. This paper presents an adaptive network convolutional coding for cooperative relaying, employing convolutional coding at the relay station instead of XOR to combine packets from two or more different sources, and then forwarding the mixed packets which can be seen as an output of the convolutional encoder to the destination side. When channels are in deep fading, this paper proposes a loose adaptive network convolutional coding for cooperative relaying, relaxing the conditions of the relay participating in forwarding. The proposed method can offer an increased robustness, adapt to the changing network topology, and reduce the number of relays required in network coding for cooperative relaying. Theoretical analysis and simulations indicate that the proposed method compared with network coding for cooperative relaying can get substantial increase in performance especially with the increased number of collaboration nodes and ensures the system of additional stability full diversity gain.