Multiple-sample processing for increasing the A/D resolution

Increasing sensitivity and resolution of analog-to-digital converters (A/Ds) for given sampling rate and analog bandwidth is very important for signal processing in digital receivers. However, conventional ways of increasing these parameters encounter formidable technological difficulties when it is necessary to maximize the product of the A/D resolution and sampling rate. The method presented in this paper is based on joint processing of M signal samples and uses the effect of reduction of each sample contribution to the quantization errors of algebraic sums of these samples when the individual samples and the sums are quantized by A/Ds with the same quantization steps. To utilize this effect, only the least significant bits (LSBs) of the quantized samples and the corresponding portions of the samplespsila analog values are summed so that the sums are components of the Walsh spectrum of the processed sequence of samples. Simulation results verifying the effectiveness of this method are presented.