Cross-Layer User Pairing for CSM in IEEE 802.16 Networks

A novel method to solve the pairing problem for Collaborative Spatial Multiplexing (CSM) in IEEE 802.16 networks is proposed in this letter. This method profiles the traffic generated by mobile stations according to their QoS requirements. User pairs with similar traffic profiles and physical layer compatibility are chosen. We show how the pairing problem can be reduced to a minimum weight perfect matching problem which can be polynomially solved using Edmond's algorithm. Simulation results show that the proposed method improves the capacity of the system by at least 20% while reducing the delay for real-time traffic by about 15%.