Low Resolution Digital-to-Analog Converter with Digital Dithering for MIMO Transmitter

TL;DR

This paper introduces a digital dithering method for MIMO transmitter DACs that reduces resolution needs, is computationally simple, compatible with standards, and does not require channel information.

Contribution

It proposes a novel digital dithering technique based on an equivalent quantizer model to improve DAC performance in MIMO systems.

Findings

Uniform dithering PDF yields optimal linear results.

Method significantly reduces DAC resolution requirements.

Approach is computationally efficient and standard-compatible.

Abstract

Based on an equivalent model for quantizers with noisy inputs recently presented in [35], we propose a method of digital dithering at the transmitter that may significantly reduce the resolution requirements of MIMO downlink Digital to Analog Convertors (DAC). We use this equivalent model to analyze the effect of the dither Probability Density Function (PFD), and show that the uniform PDF produces an optimal (linear) result. Relative to other methods of DAC quantization error reduction our approach has the benefits of low computational complexity, compatibility with all existing standards, and blindness (no need for channel state information).