上行链路(Uplink,UL)和下行链路(Downlink,DL)解耦是第六代移动通信网络(the sixth-generation mobile communication networks,6G)的一个关键特性,可以增强覆盖范围、能源效率和频谱效率。然而,6G中的上下行链路解耦技术指标分析在很...上行链路(Uplink,UL)和下行链路(Downlink,DL)解耦是第六代移动通信网络(the sixth-generation mobile communication networks,6G)的一个关键特性,可以增强覆盖范围、能源效率和频谱效率。然而,6G中的上下行链路解耦技术指标分析在很大程度上仍然是空白的。讨论了上下行传输中用户接入方案,推导了多种情况下的下行链路接入概率。在此基础上,进一步推导了上行链路和下行链路中断概率表达式,且利用柯西-施瓦茨不等式分析了上行链路中断概率的下界。仿真结果表明,推导的性能解析表达式与蒙特卡罗仿真结果相吻合,中等信噪比时,理论下界与真实值之间的间隙很小。展开更多
针对移动卫星L频段上行信号侦收覆盖范围小导致难以监测广大区域用户上行通信行为的问题,提出了一种基于协同侦收的卫星上/下行信号关联方法。通过构建协同侦收方案,实现卫星通信过程中返向链路的L频段上行信号、C频段下行信号与前向链...针对移动卫星L频段上行信号侦收覆盖范围小导致难以监测广大区域用户上行通信行为的问题,提出了一种基于协同侦收的卫星上/下行信号关联方法。通过构建协同侦收方案,实现卫星通信过程中返向链路的L频段上行信号、C频段下行信号与前向链路的L频段下行信号的协同接收,之后综合利用卫星随机接入信道(Satellite Random Access Channel,S-RACH)和卫星访问授权信道(Satellite Access Grant Channel,S-AGCH)的信号外部特征和信息内涵进行L频段上行信号和C频段下行信号之间关联分析,最终得到一种可用于关口站信号侦收的卫星上/下行信号关联方法。实验验证结果表明,所提方法具备可行性,可为后续开展基于大站的卫星信号通联分析提供技术支撑。展开更多
为解决第五代移动通信(5th generation mobile system,5G)场景下的极化码编码设计问题,通过对两种符合5G保准规定的控制上下行信道最大编码长度的极化码进行MATLAB仿真测试,通过对多种编码方式的平均编码时间进行比较,得到了最佳的极化...为解决第五代移动通信(5th generation mobile system,5G)场景下的极化码编码设计问题,通过对两种符合5G保准规定的控制上下行信道最大编码长度的极化码进行MATLAB仿真测试,通过对多种编码方式的平均编码时间进行比较,得到了最佳的极化码编码方式。结果表明:对于上下行信道来说,在码元长度一定的情况下,不实施比特反转的生成矩阵的编码方法的用时最短编码效率最高、用时最短。展开更多
针对非理想信道状态信息(CSI,channel state information)下的多小区下行时分复用(TDD,time division multiplexing)大规模多入多出(MIMO,multiple-input multiple-output)系统,研究了基于服务质量(QoS,quality of service)的发射功率...针对非理想信道状态信息(CSI,channel state information)下的多小区下行时分复用(TDD,time division multiplexing)大规模多入多出(MIMO,multiple-input multiple-output)系统,研究了基于服务质量(QoS,quality of service)的发射功率和小区间泄露功率最小的波束成形问题。首先,将目标问题近似成凸优化问题,然后,利用上下行链路对偶性,提出一种内外层迭代算法。数值分析结果表明,所提算法与其他几种典型的多小区波束成形算法相比,在算法复杂度和能量效率性能指标方面具有明显优势。展开更多
This paper mainly introduces some related problems about special mobile communication signal based on TD-LTE and TD-SCDMA in high-speed railway, summaries the main difficulty of TD-LTE coverage in high-speed railway a...This paper mainly introduces some related problems about special mobile communication signal based on TD-LTE and TD-SCDMA in high-speed railway, summaries the main difficulty of TD-LTE coverage in high-speed railway and analyses TD & LTE wireless network coverage characteristics and key technologies under the environment of high-speed railway. First, we make a contrast of the coverage range of TD<E uplink and downlink in ordinary and special situations. Then we consider effective cover radius, the distance and grazing angle between stations and railway in 2G/3G/4G networks, calculate different distance between stations. Last, we did capacity planning for TD & LTE as telephone traffic throughput required in high-speed railway. The result shows that distance between stations is limited by LTE on sharing station address. Using single RRH with two antennas, the antenna height is 30m, and the speed of the train is 250 KM/h, the RRH distance among different cells can be 1177 m, and the RRH distance among same cells can be 1311 m. In the tunnel scene, the leakage cable cover is used and the station space distance of TD & LTE is 0.5 km. Tunnel station should move the switch belt to outdoors as much as possible without switching. This paper finished the link budget, protection distance measurement of cells and study of coverage method in the tunnel scene. The result helps guiding in planning, designing and optimizing for high-speed railway network in reality.展开更多
文摘上行链路(Uplink,UL)和下行链路(Downlink,DL)解耦是第六代移动通信网络(the sixth-generation mobile communication networks,6G)的一个关键特性,可以增强覆盖范围、能源效率和频谱效率。然而,6G中的上下行链路解耦技术指标分析在很大程度上仍然是空白的。讨论了上下行传输中用户接入方案,推导了多种情况下的下行链路接入概率。在此基础上,进一步推导了上行链路和下行链路中断概率表达式,且利用柯西-施瓦茨不等式分析了上行链路中断概率的下界。仿真结果表明,推导的性能解析表达式与蒙特卡罗仿真结果相吻合,中等信噪比时,理论下界与真实值之间的间隙很小。
文摘针对移动卫星L频段上行信号侦收覆盖范围小导致难以监测广大区域用户上行通信行为的问题,提出了一种基于协同侦收的卫星上/下行信号关联方法。通过构建协同侦收方案,实现卫星通信过程中返向链路的L频段上行信号、C频段下行信号与前向链路的L频段下行信号的协同接收,之后综合利用卫星随机接入信道(Satellite Random Access Channel,S-RACH)和卫星访问授权信道(Satellite Access Grant Channel,S-AGCH)的信号外部特征和信息内涵进行L频段上行信号和C频段下行信号之间关联分析,最终得到一种可用于关口站信号侦收的卫星上/下行信号关联方法。实验验证结果表明,所提方法具备可行性,可为后续开展基于大站的卫星信号通联分析提供技术支撑。
文摘为解决第五代移动通信(5th generation mobile system,5G)场景下的极化码编码设计问题,通过对两种符合5G保准规定的控制上下行信道最大编码长度的极化码进行MATLAB仿真测试,通过对多种编码方式的平均编码时间进行比较,得到了最佳的极化码编码方式。结果表明:对于上下行信道来说,在码元长度一定的情况下,不实施比特反转的生成矩阵的编码方法的用时最短编码效率最高、用时最短。
文摘针对非理想信道状态信息(CSI,channel state information)下的多小区下行时分复用(TDD,time division multiplexing)大规模多入多出(MIMO,multiple-input multiple-output)系统,研究了基于服务质量(QoS,quality of service)的发射功率和小区间泄露功率最小的波束成形问题。首先,将目标问题近似成凸优化问题,然后,利用上下行链路对偶性,提出一种内外层迭代算法。数值分析结果表明,所提算法与其他几种典型的多小区波束成形算法相比,在算法复杂度和能量效率性能指标方面具有明显优势。
文摘This paper mainly introduces some related problems about special mobile communication signal based on TD-LTE and TD-SCDMA in high-speed railway, summaries the main difficulty of TD-LTE coverage in high-speed railway and analyses TD & LTE wireless network coverage characteristics and key technologies under the environment of high-speed railway. First, we make a contrast of the coverage range of TD<E uplink and downlink in ordinary and special situations. Then we consider effective cover radius, the distance and grazing angle between stations and railway in 2G/3G/4G networks, calculate different distance between stations. Last, we did capacity planning for TD & LTE as telephone traffic throughput required in high-speed railway. The result shows that distance between stations is limited by LTE on sharing station address. Using single RRH with two antennas, the antenna height is 30m, and the speed of the train is 250 KM/h, the RRH distance among different cells can be 1177 m, and the RRH distance among same cells can be 1311 m. In the tunnel scene, the leakage cable cover is used and the station space distance of TD & LTE is 0.5 km. Tunnel station should move the switch belt to outdoors as much as possible without switching. This paper finished the link budget, protection distance measurement of cells and study of coverage method in the tunnel scene. The result helps guiding in planning, designing and optimizing for high-speed railway network in reality.
