Queue-Aware Power Allocation for Space-Time Block Coded MIMO Systems

A queue-aware power allocation scheme for multiple-output multiple-input (MIMO) system using space time block coding (STBC) is presented. In the the physical layer, along with space-time block coded MIMO, the authors consider adaptive modulation to enhance transmission rate and error performance. To improve data reliability, automatic request (ARQ) is used for retransmission of erroneous packets from the radio link level queue. The proposed power allocation scheme is designed to minimize the cost which is defined as a function of transmit power and packet dropping probability at the radio link level queue. The genetic algorithm is used to obtain the solutions for the optimal parameters of the queue-aware power allocation scheme to minimize radio resource usage while meeting the quality-of-service (QoS) requirements for data traffic. A queueing analytical model is presented to investigate the link level performances (e.g., average queue length, packet dropping probability, throughput, and average delay) under different physical layer parameter setting.