Multiuser Capacity and Fairness Evaluation of Channel/QoS-Aware Multiplexing Algorithms

In this work multiplexing of variable-rate sources over shared generic multiple fading channels is addressed. In general, the performance of existing multiplexing algorithms has been compared in very specific environments, making it difficult to draw general conclusions. In this article we propose a generic variable-rate multiuser and multichannel system model that can be applied to any orthogonal channel multiplexing mechanism (e.g., TDM, OFDM, CDM, or SDM) through parametric modeling. Based on the model, the performance of different multiplexing algorithms proposed in the literature is evaluated over moderately fast fading snared channels. Physical channel conditions, random traffic arrival, and QoS requirements are taken into consideration in the study. Multiuser capacity and fairness are assessed and evaluated for different channel-aware and/or QoS-aware user multiplexing algorithms. Results show the joint diversity gain and QoS in terms of the throughput and delay experienced by different user information flows