This paper studies the effect of phase noise and fronthaul compression on a downlink cloud radio access network(C-RAN), where several remote radio heads(RRHs) are coordinated to communicate with users by a baseband un...This paper studies the effect of phase noise and fronthaul compression on a downlink cloud radio access network(C-RAN), where several remote radio heads(RRHs) are coordinated to communicate with users by a baseband unit(BBU) on the cloud server. In the system, the baseband signals are precoded at BBU, and then compressed before being transmitted to RRHs through capacity-limited fronthaul links which results in the compressive quantization noise. We assume the regularized zero-forcing precoding is performed with an imperfect channel state information and a compression strategy is applied at BBU. The effect of phase noise arising from nonideal local oscillators both at RRHs and users is considered. We propose an approximate expression for the downlink ergodic sum-rate of considered C-RAN utilizing large dimensional random matrix theory in the large-system regime. From simulation results, the accuracy of the approximate expression is validated, and the effect of phase noise and fronthaul compression can be analyzed theoretically based on the approximate expression.展开更多
基于实时数字仿真系统(real time digital simulation,RTDS)和数字励磁调节器(automatic voltage regulator,AVR)装置构建了物理数字联合仿真平台,并针对AVR辅助控制及限制环节功能可能存在的缺陷设计了包括低频振荡、过励、进相和定子...基于实时数字仿真系统(real time digital simulation,RTDS)和数字励磁调节器(automatic voltage regulator,AVR)装置构建了物理数字联合仿真平台,并针对AVR辅助控制及限制环节功能可能存在的缺陷设计了包括低频振荡、过励、进相和定子过流等项目的试验方案。利用RDTS对某AVR装置进行建模仿真,并在时域范围内比较仿真模型与实际装置对各种扰动的动态响应,验证了试验方法和仿真建模的正确性,并分析指出了该AVR装置在强励限制上特性与国标要求不一致之处。展开更多
基金supported in part by the Natural Science Foundation of China (NSFC) under Grant U1805262, 61871446, and 61671251supported by NSFC under Grant 61625106 and Grant 61531011
文摘This paper studies the effect of phase noise and fronthaul compression on a downlink cloud radio access network(C-RAN), where several remote radio heads(RRHs) are coordinated to communicate with users by a baseband unit(BBU) on the cloud server. In the system, the baseband signals are precoded at BBU, and then compressed before being transmitted to RRHs through capacity-limited fronthaul links which results in the compressive quantization noise. We assume the regularized zero-forcing precoding is performed with an imperfect channel state information and a compression strategy is applied at BBU. The effect of phase noise arising from nonideal local oscillators both at RRHs and users is considered. We propose an approximate expression for the downlink ergodic sum-rate of considered C-RAN utilizing large dimensional random matrix theory in the large-system regime. From simulation results, the accuracy of the approximate expression is validated, and the effect of phase noise and fronthaul compression can be analyzed theoretically based on the approximate expression.
文摘基于实时数字仿真系统(real time digital simulation,RTDS)和数字励磁调节器(automatic voltage regulator,AVR)装置构建了物理数字联合仿真平台,并针对AVR辅助控制及限制环节功能可能存在的缺陷设计了包括低频振荡、过励、进相和定子过流等项目的试验方案。利用RDTS对某AVR装置进行建模仿真,并在时域范围内比较仿真模型与实际装置对各种扰动的动态响应,验证了试验方法和仿真建模的正确性,并分析指出了该AVR装置在强励限制上特性与国标要求不一致之处。
