This work studies a multi-cell one-bit massive multiple-input multiple-output (MIMO) system that employs one-bit analog-to-digital converters (ADCs) and digital-to-analog converters (DACs) at each base station (BS). We utilize Bussgang decomposition to derive downlink signal-to-quantization-plus-interference-plus-noise ratio (SQINR) and ergodic achievable rate expressions under one-bit quantized maximum ratio transmission (MRT) and zero-forcing (ZF) precoding schemes considering scenarios with and without pilot contamination (PC) in the derived channel estimates. The results are also simplified for the mixed architecture that employs full resolution (FR) ADCs and one-bit DACs, and the conventional architecture that employs FR ADCs and DACs. The SQINR is shown to decrease by a factor of $2/\pi$ and $4/\pi^2$ in the one-bit setting compared to that achieved in the mixed setting and conventional setting respectively under MRT precoding without PC. Interestingly, the decrease in SQINR is less when we consider PC, which is shown to adversely impact the conventional system more than the one-bit system. Similar insights are obtained under ZF precoding with the decrease in the SQINR with the use of one-bit ADCs and DACs being more pronounced. We utilize the derived expressions to yield performance insights related to power efficiency, the numbers of antennas needed by the three architectures to achieve the same sum-rate, and energy efficiency.
翻译:本文研究了一种多小区单比特大规模多输入多输出(MIMO)系统,该系统在每个基站(BS)处采用单比特模数转换器(ADC)和数模转换器(DAC)。我们利用Bussgang分解,在考虑导频污染(PC)或不考虑导频污染的情况下,推导出基于单比特量化的最大比传输(MRT)和迫零(ZF)预编码方案下的下行链路信噪-量化-干扰-噪声比(SQINR)及遍历可达速率表达式。这些结果也简化适用于采用全分辨率(FR)ADC和单比特DAC的混合架构,以及采用FR ADC和DAC的传统架构。研究表明,在无PC的MRT预编码下,单比特设置中的SQINR相比混合设置和传统设置分别降低了$2/\pi$和$4/\pi^2$。有趣的是,当考虑PC时,SQINR的下降幅度较小,表明PC对传统系统的不利影响大于单比特系统。在ZF预编码下也获得了类似结论,但采用单比特ADC和DAC时SQINR的下降更为显著。我们利用推导出的表达式,获得了关于功率效率、三种架构为实现相同总速率所需的天线数量以及能效的性能洞察。