Per-tone margin optimization in multi-carrier communication systems

This paper investigates the unequal allocation of margin across tones in a multicarrier communication system. Using empirical statistics of the channel signal-to-noise-ratio variation, an algorithm is developed for modems to optimally distribute the available margin across tones instead of allocating equal per-tone margins. Such unequal per-tone margin allocation results in better stability of the line in terms of the outage probability especially when bit and energy adaptation mechanisms are not available or respond slowly to changes in the channel or noise spectrum.