Modulation-mode and power assignment in SVD-equalized MIMO systems

Abstract

Existing bit loading and transmit power allocation techniques are often optimized for maintaining both a fixed transmit power and a fixed target bit-error rate while attempting to maximize the overall data-rate. However, delay-critical real-time interactive applications, such as voice or video transmission, may require a fixed data rate. In this contribution the number of activated layers in a multiple input multiple output (MIMO) system and the number of bits per symbol along with the appropriate allocation of the transmit power are jointly optimized under the constraint of a given fixed data throughput. Our results show that in order to achieve the best bit-error rate, not necessarily all MIMO layers have to be activated. .