Ou Zeliang, Liu Xiaofeng, Yang Hongwen
School of Wireless Communication Center, Beijing University of Posts and Telecommunications, Beijing 100876, China.
China Academy of Information and Communications Technology, Beijing 100191, China.
Entropy (Basel). 2022 Mar 24;24(4):448. doi: 10.3390/e24040448.
The future 6G mobile communication network will support an unprecedented amount of Internet of Things (IoT) devices, which will boost the demand for low cost terminals under the principle of green communication. One of the critical issues for low cost terminals is the sampling rate of analog-to-digital converters (ADCs) at the receivers. A high sampling rate of the ADC gives rise to a high energy consumption and high hardware cost for the terminal. In the conventional multi-user OFDM systems, all users have to sample the received signal with a sampling rate that is larger than or equal to the Nyquist rate, despite only a small fraction of the bandwidth (number of subcarriers) is allocated to each user. This paper proposes a low sampling rate receiver design for multi-antenna multi-user OFDM systems. With the aid of zero-forcing precoding, the sampling rate of the receiver can be reduced to 1/K of the Nyquist rate, where is the number of users. The simulation results show that with a significant reduction in sampling rate, performance loss is insignificant and acceptable in terms of bit error rate, mutual information and peak-to-average power ratio.
未来的6G移动通信网络将支持数量空前的物联网（IoT）设备，这将在绿色通信原则下推动对低成本终端的需求。低成本终端的关键问题之一是接收器处模数转换器（ADC）的采样率。ADC的高采样率会导致终端的高能耗和高硬件成本。在传统的多用户OFDM系统中，尽管每个用户仅分配了一小部分带宽（子载波数量），但所有用户都必须以大于或等于奈奎斯特速率的采样率对接收信号进行采样。本文提出了一种用于多天线多用户OFDM系统的低采样率接收器设计。借助迫零预编码，接收器的采样率可以降低到奈奎斯特速率的1/K，其中K是用户数量。仿真结果表明，在采样率显著降低的情况下，误码率、互信息和峰均功率比方面的性能损失微不足道且可以接受。
