Rate-maximizing power allocation in OFDM based on partial channel knowledge

Power loading algorithms improve the data rates of OFDM systems. However, they require the transmitter to have perfect channel state information, which is impossible in most wireless systems. We investigate the effects of imperfect (and thus partial) channel feedback on the achievable rates of OFDM systems. Two cases are studied: i) ergodic channels, where average rate is the figure of merit; and ii) quasistatic channels, where the outage rate is relevant. Power loading algorithms and the effects of channel multipath are investigated analytically and with simulations.