The efficiency of discrete sine and cosine transforms of random sequences

Analytic relations for calculating the efficiency of discrete sine and cosine transforms are obtained and are found to be equally close to the optimal (in the sense of having minimum variance of the error for a fixed number of coefficients), each in its own domain: the sine transform for random Markov sequences with negative autocorrelation coefficient and the cosine transform for Markov sequences with positive autocorrelation coefficient. Copyright (C) 1997 Elsevier Science Ltd.