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Tan X.,Harbin Institute of Technology | Tan X.,Key Laboratory of Police Wireless Digital Communication | Yin C.,Harbin Institute of Technology | Ma L.,Harbin Institute of Technology
2014 21st International Conference on Telecommunications, ICT 2014 | Year: 2014

In cognitive radio system, it is still a problem that resources scheduling is unfairness if secondary users (SUs) locate at the disadvantage position around the base station when spectrum aggregation technology is involved to support high speed data transmission. A positional proportional fairness scheduling is advised based on spectrum aggregation to solve this problem. This paper focuses on the relation between spectrum aggregation and unfairness of SUs caused by disadvantage position. Bandwidth fairness can be improved as much as possible after considering positional parameters and the remaining data queue length of SUs. Simulation results show that the proposed scheduling takes advantage of bandwidth fairness comparing the scheduling without positional parameters. Meanwhile it presents that the proposed scheduling has lower bandwidth jitter to make sure of fairness among SUs and high efficiency of system. © 2014 IEEE. Source


Sun P.,Harbin Institute of Technology | Sun P.,Key Laboratory of Police Wireless Digital Communication | Feng G.,Harbin Institute of Technology | Guan K.,Harbin Institute of Technology | Zhang Y.,Harbin Institute of Technology
Lecture Notes in Electrical Engineering | Year: 2016

Science and Technology Informatization Bureau of the Ministry of Public Security released the new generation of police use digital trunking standard PDT in April 2010 in Beijing. Based on brief description of PDT and Tetra standards, this paper comparatively analyzes the specific performance indicators of two standard PDT and Tetra from the aspects of voice quality, voice services, data services, and so on. The analysis shows that advantages of PDT in terms of operational capacity is more obvious, and it is more in line with the development needs of Chinese police trunking communication system. © Springer India 2016. Source


Sun P.,Harbin Institute of Technology | Sun P.,Key Laboratory of Police Wireless Digital Communication | Tian R.,Harbin Institute of Technology | Xue H.,Harbin Institute of Technology | Wan K.,Harbin Institute of Technology
Lecture Notes in Electrical Engineering | Year: 2016

This paper analyzes the standard of TETRA which is the existing digital trunking system evolution in our country and introduces the new requirements and characteristic of the channel technology for a new generation of broadband wireless trunking system of our country in detail. On this basis, this paper analyzes and simulates the new generation of PDT standard in the view of channel technology such as synchronization technology, channel modulation, and channel coding, respectively, and compares the performance of two plans. Analysis results show that China’s independent development and customization of a new generation of police digital trunking standard PDT is more in line with the national conditions and has showed great advantages. It will gradually replace the TETRA and become the mainstream of public security digital trunking system. © Springer India 2016. Source


Jiao Y.,Harbin Institute of Technology | Ma L.,Harbin Institute of Technology | Ma L.,Key Laboratory of Police Wireless Digital Communication | Xu Y.,Harbin Institute of Technology | Xu Y.,Key Laboratory of Police Wireless Digital Communication
5th International Conference on Computing Communication and Networking Technologies, ICCCNT 2014 | Year: 2014

This paper proposed a smart handover algorithm based on fuzzy neural network. In LTE Two-tier Macrocell/Femtocell Systems, the fuzzy neural network is used to select the appropriate network which to access to taking several factors into consideration. As radius of Femtocell coverage is small, it is essential to introduce UE speed pre-judgement module in order to reduce unnecessary handovers. In the offline phase, information of UE speed, Femtocell and Macrocell RSS(Received Signal Strength), network load are collected to establish an initial database. Fuzzy neural network is trained by means of BP algorithm with training data which has been pre-processed. After establishing fuzzy neural network, information of UE speed, Femtocell and Macrocell RSS, network load is mapped with network accessing decipline. In the online phase, collecting user real-time measurement of the three-dimensional information above as the fuzzy neural network input, result of handover decision will be given through fuzzy neural system. Experimental results indicate that this algorithm can achieve a lower Ping-pong handover rate than other handover algorithms, such as RSS based algorithm and Femtocell first algorithm. © 2014 IEEE. Source


Lin M.,Harbin Institute of Technology | Lin M.,Key Laboratory of Police Wireless Digital Communication | Xiuming Z.,Harbin Institute of Technology | Danyang Q.,Heilongjiang University | Yang L.,Harbin Institute of Technology
Proceedings - 2014 4th International Conference on Instrumentation and Measurement, Computer, Communication and Control, IMCCC 2014 | Year: 2014

Wireless local networks (WLANs) are being deployed rapidly all over the world, which often contain large numbers of idle APs. The purpose of Green WLAN is to reduce the energy consumption without compromising the quality of service for end-users. In this paper, a dynamic and adaptive control algorithm of AP is proposed in order to save energy and prolong the service lives of APs. It includes AP selection which is solved with genetic algorithm and aimed to guarantee the whole coverage of WLAN, AP clustering, and the dynamic control algorithm of AP. Then simulation is operated on a virtual WLAN of high-density. The result shows that the dynamic and adaptive control algorithm of AP can indeed save much energy and improve the use efficiency of APs. © 2014 IEEE. Source

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