Zhong Zhangdui

Novel statistical processing methods for wireless field strength prediction

This paper mainly deals with the statistical processing methods in wireless filed strength prediction process after sampling data are collected. The conventional standard for data collection and statistical processing in the prediction of wireless filed strength is Lees criteria. It utilizes linear averaging to process sampling data, as many other related papers discussed. However, the accuracy of such first order moment estimation is low, especially under serious Rayleigh fading channels. As regards to the defects of the method, we propose four novel statistical processing methods to process the collected data for wireless field strength. Computer simulations and corresponding analysis verify its much better prediction results with small estimation variances.

Green circuit design for battery-free sensors in cloud radio access network

Cloud radio access network (C-RAN) is considered as a promising approach to solve the bandwidth crunch problem for future wireless network. Another important element for future network is sensors that can monitor physical or environmental conditions. Currently, most sensors need batteries for power, which is energy-consuming and maintenance-heavy. To further improve energy efficiency (EE) of sensors in C-RAN, this paper proposes a new structure as well as practical circuit design for green sensors in C-RAN. The structure can enable sensors to harvest energy from radio signals transmitted by neighbor remote radio heads (RRHs) and user terminals (UTs). To demonstrate the validity of the new structure, a practical circuit design is suggested and the corresponding hardware platform is realized. Specifically, selection criteria for electrical component parameters and design of an impedance-matching network are discussed in details. In addition, two methods to stabilize the output voltage are proposed and analyzed. Finally, simulation results as well as experimental results are provided to corroborate our proposed studies.

Interference Assessment in the High-Speed Railway Wireless Communication Networks by AHP-GRAP

Interference is a critical problem in the wireless communication networks, and interference performance assessment is of great sensibility necessity. This paper proposes a new comprehensive interference assessment method, AHP-GRAP (Analytic Hierarchy Process - Grey Relational Analysis Process, AHP-GRAP) method. And the AHP-GRAP is applied to a real case to resolve the interference assessment problem in the high-speed railway wireless communication networks in this paper. In the proposed AHP-GRAP method, the relative weights of QoS (Quality of Service, QoS) criteria in the high-speed railway wireless communication networks are determined by AHP, and then these weights are used as coefficients of GRAP model. Based on the optimal value of the QoS in the high-speed railway wireless communication networks, GRAP is then used to perform the evaluation of interference. The results show that AHP-GRAP is a more comprehensive method to reflect the interference state of the systems than existing single criteria interference assessment algorithms.

Strategy research of optimizing effective radio coverage

The rapid increase of mobile communication network requires a more deliberate network planning, in which determining the effective coverage is one of the most important problems in network planning and optimization. Aiming at the problems in determining user-oriented effective coverage, propose to optimize some key parameters to improve the coverage equality, and carry on the corresponding simulation.