Variable Rate Variable Power MIMO System for Integrated Voice and Data Services

We propose an adaptive rate and power allocation algorithm for integrated voice and data services in a multiple input multiple output (MIMO) system. Given the available power at the MIMO transmitter is limited, the voice service is given the highest priority and appropriate power is allocated to satisfy the bit error rate (BER) requirement for voice transmission. Based on the remaining average power, optimal rate and power adaptations for maximum spectral efficiency under a BER requirement are performed for data transmission. We formulate the optimization problem based on m independent and identical single input single output optimization problems and solve for optimal rate and power adaptations. For voice transmission, a fixed rate transmission scheme and a channel inversion type power control policy are employed. For data transmission, an adaptive rate based on multilevel quadrature amplitude modulation (MQAM) scheme and a water-filling type adaptive power control are employed. Finally we study the performance of the proposed algorithms using analytical and simulation results