Adaptive analog coding for video broadcast in wireless cooperative system

In wireless video broadcast system, analog JSCC (joint source-channel coding) schemes have attracted extensive attentions recently as they can avoid the cliff effect that occurs along with the conventional separate digital source/channel coding schemes. User cooperation is a new promising technology in wireless broadcast system, but conventional digital cooperative coding scheme is not very suitable to the present analog broadcast system because of the cliff effect. In this paper, we propose an adaptive cooperative video coding (ACVC) scheme for video broadcast in wireless cooperative system based on the analog JSCC and coset coding principles. Specifically, ACVC adopts a series of adaptive algorithms to adjust the transmission parameters and the coset code steps according to the channel condition and the feature of each packet. From the experimental results we can see that, in comparison with existing cooperative schemes, ACVC shows stronger adaptability, especially when the cooperative channel condition is worse than the source-relay channel or when the cooperative bandwidth is limited.