Massive multi-input–multi-output (MIMO) is expected to be an eminent technique to meet the demands of high system capacity and data rates of wireless networks in 5G wireless communication. However due to inherent imperfections of the transmitter such as power-amplifier (PA) non-linearity and crosstalk, practically, the signal quality suffers and does not reap sufficient benefits from the various MIMO techniques. Digital predistortion (DPD) is a popular technique for single-input–single-output transmission to enhance signal quality. This study examines the issue of high DPD's complexity in mitigating imperfections in MIMO transmitters. This work proposes a less complex, novel DPD model for linearising large-scale MIMO transmitters along with its characterisation procedure. The proof-of-concept is provided with the measurement setup containing 4 1 MIMO transmitters in the presence of non-linear crosstalk, linear crosstalk, and strong PA non-linearity. The proposed model performs comparably to the state-of-art DPD models like parallel Hammerstein and dual-input crosstalk mismatch with lower number of floating-point operations (flops). The proposed model improves adjacent channel power ratio up to dBc and error vector magnitude up to 1.08% for LTE signal of 40 MHz bandwidth.

中文翻译：

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适用于大规模MIMO发射机的串扰和功率放大器非线性的高效线性化技术

大规模多输入多输出（MIMO）有望成为满足5G无线通信中高系统容量和无线网络数据速率要求的一项杰出技术。但是，由于发射机的固有缺陷，例如功率放大器（PA）的非线性和串扰，实际上，信号质量受到影响，无法从各种MIMO技术中获得足够的收益。数字预失真（DPD）是一种用于单输入单输出传输以提高信号质量的流行技术。这项研究探讨了DPD复杂度高的问题，以缓解MIMO发射机的缺陷。这项工作提出了一种用于线性化大型MIMO发射机的较简单，新颖的DPD模型及其表征程序。测量设置随附概念验证，其中包含4个 1 MIMO发射机存在非线性串扰，线性串扰和强PA非线性的情况。所提出的模型与最新的DPD模型（如并行Hammerstein和双输入串扰不匹配）具有较少的浮点运算（触发器）性能相当。提出的模型将相邻信道的功率比提高到 对于40 MHz带宽的LTE信号，dBc和误差矢量幅度高达1.08％。