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
以某半导体封装测试(Semiconductor assembly and test manufacturing,ATM)企业为研究背景,对半导体封装测试的生产过程进行分析总结,提出一种新的"产能限定混线车间"(Capacity-limit flexible flow-shop,CLFFS)模型作为半导...以某半导体封装测试(Semiconductor assembly and test manufacturing,ATM)企业为研究背景,对半导体封装测试的生产过程进行分析总结,提出一种新的"产能限定混线车间"(Capacity-limit flexible flow-shop,CLFFS)模型作为半导体封装测试生产线的排产模型.通过对半导体封装测试的特殊逻辑处理、排产方法以及排产规则等进行研究,提出采用逻辑约束和调度规则双层优化控制的启发式正序排产算法作为半导体封装测试的总体排产方法,同时针对批准备单处理生产阶段,提出一种新的预测开机控制优化调度方法.最后,结合CLFFS排产模型和所提出的策略方法,给出半导体封装测试排产的应用研究示例与比较,结果证明本文给定的总体排产方法在ATM中具有很好的可行性和业务逻辑嵌入的即便性,同时本文所提出的新的预测开机控制优化调度方法能够很好的缩短生产周期,提高生产效率.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.
文摘以某半导体封装测试(Semiconductor assembly and test manufacturing,ATM)企业为研究背景,对半导体封装测试的生产过程进行分析总结,提出一种新的"产能限定混线车间"(Capacity-limit flexible flow-shop,CLFFS)模型作为半导体封装测试生产线的排产模型.通过对半导体封装测试的特殊逻辑处理、排产方法以及排产规则等进行研究,提出采用逻辑约束和调度规则双层优化控制的启发式正序排产算法作为半导体封装测试的总体排产方法,同时针对批准备单处理生产阶段,提出一种新的预测开机控制优化调度方法.最后,结合CLFFS排产模型和所提出的策略方法,给出半导体封装测试排产的应用研究示例与比较,结果证明本文给定的总体排产方法在ATM中具有很好的可行性和业务逻辑嵌入的即便性,同时本文所提出的新的预测开机控制优化调度方法能够很好的缩短生产周期,提高生产效率.
