This letter presents a low-resolution multiband transmitter architecture using direct digital synthesis (DDS) with dithering. Modern modulated signals constructed by a low-resolution digital-to-analog converter (DAC) suffer from quantization errors and distortions. The proposed technique reduces the quantization problems with the use of a proper oversampling ratio (OSR) and the dithering technique. This technique has lower cost and lower complexity compared to conventional transmitters while maintaining linearity performance. A 50-MHz 5G NR 256-quadratic-amplitude modulation (QAM) signal is used for concept validation at bands n1, n40, and n50. The proposed work achieved the adjacent channel leakage ratio (ACLR) and error vector magnitude (EVM) requirements of under −30 dBc and 3.5%, respectively. A single 3-bit 10-GS/s radio frequency (RF) DAC is used where the performance is similar to a conventional transmitter using a pair of 5-bit baseband in-phase and quadrature (IQ) DACs.

中文翻译：

---

一种针对多频段 5G NR 移动应用使用抖动的低分辨率直接数字合成发射机架构

这封信介绍了一种使用直接数字合成 (DDS) 和抖动的低分辨率多频带发射机架构。由低分辨率数模转换器 (DAC) 构建的现代调制信号存在量化误差和失真。所提出的技术通过使用适当的过采样率 (OSR) 和抖动技术来减少量化问题。与传统发射机相比，该技术具有更低的成本和更低的复杂性，同时保持线性性能。50 MHz 5G NR 256 二次幅度调制 (QAM) 信号用于在频段 n1、n40 和 n50 进行概念验证。所提出的工作分别实现了低于 -30 dBc 和 3.5% 的相邻信道泄漏比 (ACLR) 和误差矢量幅度 (EVM) 要求。