Coding of Stereo Signals by a Single Digital {\Delta}{\Sigma} Modulator

TL;DR

This paper presents a novel method for encoding stereo signals using a single digital { extDelta}{ extSigma} modulator, enabling efficient, low-crosstalk stereo signal processing with flexible noise shaping and potential for improved audio quality.

Contribution

It introduces a new approach to stereo signal coding with one { extDelta}{ extSigma} modulator, simplifying hardware and enhancing performance compared to traditional dual-modulator systems.

Findings

Single modulator effectively encodes stereo signals with minimal crosstalk.

Demultiplexing preserves sample depth, suitable for direct analog conversion.

Method allows improved dynamic range and SNR when one channel is unused.

Abstract

The possibility of using a single digital {\Delta}{\Sigma} modulator to simultaneously encode the two channels of a stereo signal is illustrated. From the modulated stream, the two channels can be recovered with minimal processing and no cross-talk. Notably, demultiplexing does not affect the sample-depth so that, after it, one still has a data stream suitable for directly driving a power bridge and convertible into analog by mere low-pass filtering. Furthermore, the approach is very flexible and if one channel is unused, it lets the other get improved dynamic range and SNR. The approach can take advantage of recent techniques for the design of {\Delta}{\Sigma} modulators, including methods for psychoacoustically optimal distribution of quantization noise. Code is available to replicate the proposed examples and as a general computer aided design tool.