莱斯信道下大规模MIMO系统混合模数转换器的随机向量量化方案

A residual vector quantization scheme using fixed precision analog to digital converter for massive MIMO systems over Rician fading channels

针对大规模MIMO系统用配置单精度模数转换器(ADC)来降低系统能耗会导致系统损失部分性能的问题,提出了一种莱斯信道下大规模MIMO系统的采用混合ADC的随机向量量化(RVQ)改进方案。该方案在频分双工模式下,首先在基站端采用高分辨率ADC和低分辨率ADC混合的接收方案处理信号,使接收的导频信号和有用信号具有较高的转换精度;系统对导频信号进行信道估计后,再对信道状态信息(CSI)进行RVQ处理,以此减小系统的反馈开销;最后运用最小均方误差(MMSE)信号检测算法减轻由量化误差引起的的用户间干扰,从而达到降低能耗并减小系统性能损失的目的。实验结果表明,这种改进的RVQ方案能在降低系统能耗的基础上有效减小系统容量损失,并使其和速率接近传统的高分辨率ADC接收方案。

To solve the problem that a massive MIMO system will bring about partial perfm^ance loss if it uses single- precision analog to digital converter（ADC） to reduce its energy consumption, an improved residual vector quantization （RVQ） scheme using fixed ADC for massive MIMO systems over Rician fading channels was proposed. In the frequency division duplexing （FDD） mode, the scheme uses a reception mixing the high resolution ADC and the low resolution ADC to perform signal processing in the based station to achieve the high conversion accuracy for the received pilot signal and the useful signal. After channel estimation of the pilot signal, the channel state information is processed by RVQ to lighten the feedback overhead. Finally, the minimum mean square error （MMSE） signal detection algorithm is adopted for the purpose of reducing the inter user interference caused by quantization error so as to reduce the energy consumption and the performance loss of the system. The simulation results show that the improved scheme can effectively reduce the loss of the energy consumption and the loss of system capacity, and the sum-rate performance of the proposed scheme is close to the traditional high resolution ADC receiving scheme.