POWER CONTROL SCHEMES FOR FADING ADDITIVE WHITE GAUSSIAN NOISE CHANNELSy

In this paper we propose two novel approaches to the problem of power control for fading, additive white Gaus-sian noise channels, with side information. The objective in the rst scheme is to maximize the capacity of the channel subject to a constraint on the minimum capacity at any given state of the channel. In this scheme we assume perfect knowledge of the channel state. In the second part of this paper, we approach the problem of power control for a fading channel with imperfect knowledge of the channel state. An application of this method to minimizing the bit error rate (BER) for a binary diierential phase-shift key-ing (BDPSK) modulation system is derived. The proposed power control policies are compared with other schemes found in the literature in terms of the channel capacity, the outage probabilities, the 1%-capacity, and the achieved BER.