Performance analysis of cooperative virtual multiple-input-multiple-output in small-cell networks

With the advent of small-cell networks (SCNs) to support growing wireless data volumes and thus reduced cell sizes, cooperative communications are significantly facilitated. Applicable to Third Generation Partnership Project long-term evolution-A, the authors propose a novel channel/queue-aware user pairing and scheduling scheme in a cooperative virtual multiple-input-multiple-output (VMIMO) system. The queueing performance of the VMIMO system with the scheduling scheme is analysed based on the finite-state Markov model (FSMM), and compared with that of non-cooperative systems. Bounds on the average queuing delay of users are derived by using a semi-definite programming (SDP) approach. The presented analyses are validated through comparing the analytical and simulation results. It is found that the introduced VMIMO pairing process is able to significantly reduce service delays, bringing on a positive impact of cooperative techniques on next generation wireless systems.