Multicarrier channels with non-identical subcarrier fading distributions-analysis and adaptation

In this letter, the subcarrier fading distribution of multicarrier modulation (MCM) systems is derived based on channel-impulse response (CIR) information. Frequency-selective channels with arbitrary Rician-Rayleigh fading paths and inter-path correlations are considered. It is discovered that certain MCM channels experience different fading severity among the subcarriers. Motivated by this observation, a novel bit-loading cum power-control scheme that can achieve better spectral and power efficiency by adapting the subcarrier modulation parameters based on the long-term subcarrier fading statistics, instead of instantaneous channel state information, is proposed and studied.