Stable user pairing in virtual MIMO systems: A game theoretical perspective

Virtual MIMO (VMIMO) technique has been envisioned to be an advanced technique for communication systems. In this paper, we consider a 2×2 VMIMO system, where two users are paired together to communicate with the base station simultaneously. User pairing is important for such a system since it determines the channel capacity of each pair of users, the system capacity, as well as the fairness among users. To consider the tradeoff between the system performance and user fairness, we study another concept of stability by formulating the user pairing problem as a symmetric paring game. Using a game theoretical analysis, we proof that the symmetric pairing problem exists a stable pairing solution, which is also Pareto efficient. Based on this result, we further develop a symmetric stable pairing (SSP) algorithm to find out a stable pairing for the VMIMO system. Simulation results show that the stable pairing given by SSP results in a high system capacity and an acceptable fairness.