Spectral Efficiency of Orthogonal Set of Truncated MC-CDMA Signals Using Discrete Prolate Spheroidal Sequences

In this paper, we show that a set of multicarrier code-division multiple access (MC-CDMA) signals using a set of discrete prolate spheroidal sequences achieves 95% of the maximum spectral efficiency at the out-of-band energy of 0.1% and the bandwidth-duration product of 45.25 with an orthogonalizing truncation. It is shown that the density p of carriers plays an important role in accurately estimating the out-of-band energy of the signals based on the corresponding eigenvalues and in achieving a small out-of-band energy. We also show that p should be chosen such that rho ges 4 or rho ges 8. To perform numerically stable eigenanalysis, we employ the technique of singular-value decomposition.