Multi-level QAM transceivers with adaptive power control in fixed wireless channels

Abstract

This paper considers the design of quadrature amplitude modulation(QAM) tranceivers for fixed wireless communication. We propose the use of power control in the QAM transmitter(Tx) to obtain BER performance of robust to fading. The gain of the Tx is adaptively adjusted to keep the power of the received signal nearly constant despite of the short term fading and the second multipath. The BER performance of the proposed scheme is ananlytically evaluated in fixed wireless channels with flat fading and frequency selective fading. Analytic and simulation results show that the use of power control in the Tx can provide he BER performance only about 1dB inferior to that in additive white Gaussian noise (AWGN) channel.