Bayesian Channel Estimation and Data Detection in Oversampled OFDM Receiver With Low-Resolution ADC
Bayesian Channel Estimation and Data Detection in Oversampled OFDM Receiver With Low-Resolution ADC
复制标题
具有低分辨率 ADC 的过采样 OFDM 接收器中的贝叶斯信道估计和数据检测
DOI：
10.1109/twc.2021.3068484
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发表时间：
2021-09-01
影响因子：
10.4
通讯作者：
Li, Shaoqian
中科院分区：
文献类型：
--
作者：
Cheng, Xiantao;Xia, Binyang;Li, Shaoqian
提出了一种新的正交频分复用（OFDM）接收机结构，该结构利用低分辨率模数转换器（ADC）对接收信号进行时域过采样。虽然低分辨率ADC在功耗和硬件成本方面具有吸引力，但低分辨率ADC会引起严重的非线性量化失真，从而破坏OFDM子载波之间的正交性。正交性的损失，以及过采样引起的噪声样本的相关性，对OFDM接收机的设计提出了很大的挑战。本文旨在应对这一挑战。对于建议的接收机，我们考虑了一个常用的两阶段传输协议。在第一阶段，发送训练OFDM符号用于信道估计。在第二阶段中，使用先前获得的信道估计来发送和检测传达信息的OFDM符号。因此，该接收机由两个关键部分组成：信道估计器和数据检测器。这些组件是精心推导的贝叶斯推理的框架。由于过采样操作产生的分集增益，所提出的接收机可以显着优于同行，包括传统的OFDM接收机与完美的无限精度量化。
This paper focuses on a novel orthogonal frequency division multiplexing (OFDM) receiver architecture, which uses a low-resolution analog-to-digital converter (ADC) to oversample the received signal in time domain. Although attractive in terms of power consumption and hardware cost, low-resolution ADC incurs severe nonlinear quantization distortion and thus destroys the orthogonality between the OFDM subcarriers. The loss of orthogonality, together with the oversampling-caused correlation in noise samples, poses a great challenge to the OFDM receiver design. This paper aims to tackle this challenge. For the proposed receiver, we consider an often-used two-phase transmission protocol. In the first phase, training OFDM symbols are transmitted for channel estimation. In the second phase, information-conveying OFDM symbols are transmitted and detected using the previously obtained channel estimate. Therefore, the proposed receiver consists of two key components: channel estimator and data detector. These components are elaborately derived in the framework of Bayesian inference. Due to the diversity gain resulting from the oversampling operation, the proposed receiver can remarkably outperform the counterparts, including the conventional OFDM receiver with perfect infinite-precision quantization.