无线局域网(Local Area Network,LAN)是一种部署方便的高速无线接入技术,能够利用各种信息传输网络进行实时监控、远程定位、历史记录、智能故障分析及预警等安全服务,面向物联网内的所有对象通过云系统进行监控、管理、分析和处理。基...无线局域网(Local Area Network,LAN)是一种部署方便的高速无线接入技术,能够利用各种信息传输网络进行实时监控、远程定位、历史记录、智能故障分析及预警等安全服务,面向物联网内的所有对象通过云系统进行监控、管理、分析和处理。基于互联网探讨基于无线局域网鉴别和保密基础结构(Wireless LAN Authentication and Privacy Infrastructure,WAPI)的无线网络接入终端的设计,对WAPI国家安全标准进行详细的分析和阐述,并基于WAPI技术的信息交换机制和保密结构阐述其安全通信功能,从无线网络接入终端的总体设计、硬件设计和软件设计等不同层面入手,搭建基于WAPI的无线网络接入终端系统,确保系统的安全性和稳定性。展开更多
Signal-to-noise ratio （SNR） and channel estimations are critical for 60-GHz communications to track the optimal trans- mission and reception beam pairs. However, the excessive pilot overhead for the estima- tions se...Signal-to-noise ratio （SNR） and channel estimations are critical for 60-GHz communications to track the optimal trans- mission and reception beam pairs. However, the excessive pilot overhead for the estima- tions severely reduces system throughput in fast-rotation scenarios. In order to address this problem, we firstly demonstrate the potential sparseness property of 60-GHz channel in beam tracking; subsequently, via exploiting this property, we propose a novel compressed SNR-and-channel estimation. The estimation is conducted in a three-stage fashion, includ- ing the unstructured estimation, nonzero-tap detection, and structured estimation with non- zero-tap location. Numerical simulations show that, in the case of substantial reduction of the pilot overhead, the proposed estimator still reveals a significant improvement in terms of estimation performance over the scheme in IEEE 802.1 lad. Furthermore, it is also demon- strated that the proposed SNR and channel estimators can approach the lower bounds in sparse channels so long as SNR exceeds 8 dB.展开更多
文摘无线局域网(Local Area Network,LAN)是一种部署方便的高速无线接入技术,能够利用各种信息传输网络进行实时监控、远程定位、历史记录、智能故障分析及预警等安全服务,面向物联网内的所有对象通过云系统进行监控、管理、分析和处理。基于互联网探讨基于无线局域网鉴别和保密基础结构(Wireless LAN Authentication and Privacy Infrastructure,WAPI)的无线网络接入终端的设计,对WAPI国家安全标准进行详细的分析和阐述,并基于WAPI技术的信息交换机制和保密结构阐述其安全通信功能,从无线网络接入终端的总体设计、硬件设计和软件设计等不同层面入手,搭建基于WAPI的无线网络接入终端系统,确保系统的安全性和稳定性。
基金supported by the National Natural Science Foundation of China(NSFC) under Grant No.61201189 and 61132002National High Tech(863) Projects under Grant No.2011AA010202+1 种基金Research Fund of Tsinghua University under Grant No.2011Z05117 and 20121087985Shenzhen Strategic Emerging Industry Development Special Funds under Grant No. CXZZ20120616141708264
文摘Signal-to-noise ratio （SNR） and channel estimations are critical for 60-GHz communications to track the optimal trans- mission and reception beam pairs. However, the excessive pilot overhead for the estima- tions severely reduces system throughput in fast-rotation scenarios. In order to address this problem, we firstly demonstrate the potential sparseness property of 60-GHz channel in beam tracking; subsequently, via exploiting this property, we propose a novel compressed SNR-and-channel estimation. The estimation is conducted in a three-stage fashion, includ- ing the unstructured estimation, nonzero-tap detection, and structured estimation with non- zero-tap location. Numerical simulations show that, in the case of substantial reduction of the pilot overhead, the proposed estimator still reveals a significant improvement in terms of estimation performance over the scheme in IEEE 802.1 lad. Furthermore, it is also demon- strated that the proposed SNR and channel estimators can approach the lower bounds in sparse channels so long as SNR exceeds 8 dB.
