MSE-based transmit power control for transmission of QAM signals in frequency selective fading channel

Abstract

When a multi-level quadrature amplitude modulation (QAM) signal is transmitted over the wireless channel, transmit power needs to be controlled to avoid severe performance degradation due to the fading. Most studies on the transmit power control (TPC) were considered in the flat fading channel. In this paper, we propose a power control scheme in the frequency selective fading channel, where the transmit power is controlled based on the mean-squared error (MSE) of the equalizer output. The performance of the proposed scheme is analytically evaluated and verified by computer simulation in the fixed wireless channel with low Doppler frequency.