Electronic International Standard Serial Number (EISSN)
1572-834X
abstract
The queueing process plays a crucial role in the performance that a Downlink SDMA system can achieve as it interacts with other system parameters such as the number of antennas, the traffic load and the number of active mobile nodes (MNs). This paper analyzes these interactions from the link-layer perspective, which has been traditionally ignored in the analysis of such systems. As a reference, a finite-buffer upper-bound queuing model able to predict the optimal system performance in terms of throughput (blocking probability) and system delay is presented. A comparative analysis between the considered system performance and the performance provided by the upper-bound queueing model allows to foresee the situations in which a Downlink SDMA system is underperforming and understand the reasons that cause this low performance. This knowledge is essential for the design of packet-based scheduling algorithms in order to maximize the system performance in a broad range of situations.