The multiplexing gain of wireless networks

At high SNR the capacity of a point-to point MIMO system with N _T transmit antenna and N_R receive antenna is min{N _T, N_R} log(SNR) + O(1). The factor in front of the log is called the multiplexing gain. In this paper we consider a network with 2N nodes (N source destination pairs) that each have only a single antenna. These single antenna nodes could cooperate to form larger virtual arrays, usually called cooperative diversity, user cooperation, or coded cooperation. The question we ask is: how large a multiplexing gain is possible. We prove that for N = 2 the multiplexing gain is 1, and consider generalizations to larger networks