Reliable OFDM Receiver with Ultra-Low Resolution ADC

TL;DR

This paper presents a novel low-resolution ADC-based OFDM receiver that employs advanced channel estimation and inference algorithms, validated through real-world over-the-air experiments, enabling reliable data transmission with reduced power and hardware costs.

Contribution

It introduces a new Q-OFDM channel estimator within the GTurbo framework and develops a practical receiver architecture with system implementation and OTA testing.

Findings

Reliable data transmission achieved in low-resolution ADC OFDM systems

Proposed algorithms ensure convergence and robustness

Successful over-the-air experimental validation

Abstract

The use of low-resolution analog-to-digital converters (ADCs) can significantly reduce power consumption and hardware cost. However, their resulting severe nonlinear distortion makes reliable data transmission challenging. For orthogonal frequency division multiplexing (OFDM) transmission, the orthogonality among subcarriers is destroyed. This invalidates conventional OFDM receivers relying heavily on this orthogonality. In this study, we move on to quantized OFDM (Q-OFDM) prototyping implementation based on our previous achievement in optimal Q-OFDM detection. First, we propose a novel Q-OFDM channel estimator by extending the generalized Turbo (GTurbo) framework formerly applied for optimal detection. Specifically, we integrate a type of robust linear OFDM channel estimator into the original GTurbo framework and derive its corresponding extrinsic information to guarantee its convergence. We also propose feasible schemes for automatic gain control, noise power estimation, and synchronization. Combined with the proposed inference algorithms, we develop an efficient Q-OFDM receiver architecture. Furthermore, we construct a proof-of-concept prototyping system and conduct over-the-air (OTA) experiments to examine its feasibility and reliability. This is the first work that focuses on both algorithm design and system implementation in the field of low-resolution quantization communication. The results of the numerical simulation and OTA experiment demonstrate that reliable data transmission can be achieved.