OFDM capacity enhancement by selective channel Use

If binary signaling is used in an n-channel OFDM link, the maximum possible bit rate is n bits per OFDM symbol duration. We show a simple scheme based on selective channel use that increases this capacity by nearly 60%. By using only k channels out of the n, we show how to use the choice of the k channels as an additional auxiliary channel. For proper choice of parameters, the information transferred over this auxiliary channel can be large. In this paper we study the details of such an OFDM system. We present capacity estimates and discuss methods to mitigate the effects of errors in the auxiliary channel that contribute to loss of the binary information sent on the k selected channels. Simulation results of attainable performance are presented.