Joint source coding diversity and cooperative diversity for multimedia communications

Source coding diversity produces multiple independent source descriptions so as to improve the received quality. Cooperative diversity exploits the broadcast nature of wireless networks by allowing multiple users to relay information for each other, so as to create multiple signal paths. This paper studies what is the best strategy in combining these two types of diversity for real-time multimedia communications by comparing the distortion-rate performance of different joint diversity schemes. Results show that exploring both types of diversity improves the system performance most, but in most of cases, only one type of diversity can achieve most of the diversity gain. The best performance is obtained when the mobile can switch between cooperative and non-cooperative operation depending on the channel conditions. Thus, we remark that it is important to design efficient protocols that manage this switch and provides motivation for all users to cooperate.