An Efficient Non-Uniform Multi-Tone System Based On Ramanujan Sums

摘要

Non-uniform multi-carrier Ramanujan Fourier Multi-tone (RFMT) systems have low transmission efficiency because of their large transform length. This paper demonstrated that the signs of received symbols before demodulation remain unchanged as long as the product of transform matrix and its transpose is dominated by its diagonal elements. Thus, it is possible to recover the transmitted bits from truncated transform vectors. Analysis and simulation results show that the truncated RFMT realizes non-uniform spectrum distribution similar to that of RFMT. When its transmission efficiency is twice of that of RFMT, i.e. the transform length is truncated to half of the original length, it still has the same anti-noise performance as RFMT. Thus, the truncated RFMT systems not only enjoy higher transmission efficiency, but also enable a flexible tradeoff between efficiency and reliability for various channel qualities.