The paper presents a queueing analytical model for radio link level performance analysis in spatial multiplexing multiple-input multiple-output (MIMO) wireless systems using adaptive modulation. In the physical layer, the modulation level is adaptively adjusted according to the channel quality based on quadrature amplitude modulation (QAM). In the medium access control (MAC) layer, the authors consider a time division multiple access (TDMA) scheme with weighted round-robin scheduling. Developed based on a discrete-time Markov chain and vacation queueing model, the analytical model provides various packet-level performance measures. In addition, we present an optimization formulation to obtain users' weights for packet scheduling so that the transmission rate requirements of the users can be satisfied. Afterwards, an admission control scheme is proposed.
['Dusit Niyato', 'Ekram Hossain', 'K. C. B. Wavegedara', 'Vijay K. Bhargava']
Radio Link Level Performance in Multi-Rate MIMO Wireless Networks: Analysis and Optimization