Cooperation diversity in multihop wireless networks using opportunistic driven multiple access

Cooperation among users in a multihop wireless network adds diversity to the system and thus it allows the overall transmit power to be reduced. However, cooperation requires signaling among users and this reduces the overall rate gain. We provide the optimal coding strategy for meshed wireless networks, where more links are active simultaneously, assuming as optimality criterion the rates of all the links. This is a multi-objective optimization problem that has interesting applications in multihop and ad-hoc networks. We evaluate the optimal codes in closed form for the case where there are two pairs of users acting simultaneously and we provide an iterative algorithm for the general case. Then we evaluate the loss, in terms of information rate, resulting from simultaneous cooperation.