A generalized multirate topology of reduced-sample-rate /spl Sigma//spl Delta/ modulators with optimum coefficients

A novel technique of reduced-sample-rate (RSR) sigma-delta modulation for application in PCM-to-bitstream conversion has emerged. This technique allows the sigma-delta modulator to operate at a fractional rate of the bitstream rate. The technique also exhibited some important properties such as reduced tonal amplitudes and improved stability. In this paper, a generalized multirate topology of the technique is proposed. A linear model of the multirate topology is then developed. Using this linear model, optimum canonical filter coefficients are obtained using methods such as quadratic programming.