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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.


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.


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.


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.


Zhou C.F.,Harbin Institute of Technology | Ma L.,Harbin Institute of Technology | Ma L.,Key Laboratory of Police Wireless Digital Communication | Tan X.Z.,Harbin Institute of Technology | Tan X.Z.,Key Laboratory of Police Wireless Digital Communication
27th International Technical Meeting of the Satellite Division of the Institute of Navigation, ION GNSS 2014 | Year: 2014

With the recent development in mobile computing devices and as the ubiquitous deployment of access points(APs) of Wireless Local Area Networks(WLANs), WLAN based indoor localization systems(WILSs) are of mounting concentration and are becoming more and more prevalent for they do not require additional infrastructure. As to the localization methods in WILSs, for the approaches used to localization in satellite based global position systems are difficult to achieve in indoor environments, fingerprint based localization algorithms(FLAs) are predominant in the RSS based schemes. However, the performance of FLAs has close relationship with the number of APs and the number of reference points(RPs) in WILSs, especially as the redundant deployment of APs and RPs in the system. There are two fatal problems, curse of dimensionality (CoD) and asymmetric matching(AM), caused by increasing number of APs and breaking down APs during online stage. In this paper, a semi-supervised RSS dimensionality reduction algorithm is proposed to solve these two dilemmas at the same time and there are numerous analyses about the theoretical realization of the proposed method. Another significant innovation of this paper is jointing the fingerprint based algorithm with CM-SDE algorithm to improve the localization accuracy of indoor localization. Comparing with LDE-KNN algorithm, SDE-KNN method is going to update RSS during online stage or offline stage. It is the update scheme that improves the performance of the proposed algorithm. After locally analyzing of parameters, the optimized value of each parameter could be gained. As it presents in by numeral analysis, the performance optimized parameters of SDE-KNN of it is overly better than initial KNN and LDE-KNN. The localization accuracy of SDE-KNN is higher than 70% as the error radius is 0.5 meter, and it is about 10 percent higher than initial KNN, as well as 25 percent higher than LDE-KNN. As the error radius equals to 1 meter, the proposed algorithm could gain over 95% of localization accuracy.


Chen L.,Harbin Institute of Technology | Chen L.,Key Laboratory of Police Wireless Digital Communication | Ma L.,Harbin Institute of Technology | Ma L.,Key Laboratory of Police Wireless Digital Communication | And 2 more authors.
IEEE International Symposium on Personal, Indoor and Mobile Radio Communications, PIMRC | Year: 2015

Advanced interference coordination and resource management schemes are important in heterogeneous wireless networks in order to achieve a high network capacity and good user experience. In this paper, we present a joint consideration of the sub-channel allocation and power distribution in MIMO two-tier networks where the femtocells form clusters of equal size. All of the BSs have a multi-antenna configuration utilizing zero-forcing beamforming. The optimization objective maximizes the long-term system throughput and guarantees the fairness among Femto users (FUEs) in different tiers at the same time. After that, a modified genetic algorithm (GA) is addressed to resolve the mixed-integer nonlinear programming problem involved. Each chromosome in the proposed GA is divided into an integer string for sub-channel allocation, and a real number strings for power distribution. In addition, new initialization, crossover and mutation operations are employed for this new type of chromosomes. Conducted simulations show that the proposed GA can increase the throughput of the system and guarantee the fairness among the FUEs. © 2015 IEEE.


Wang Y.,Harbin Institute of Technology | Wang Y.,Key Laboratory of Police Wireless Digital Communication | Ma L.,Harbin Institute of Technology | Ma L.,Key Laboratory of Police Wireless Digital Communication | And 2 more authors.
2016 IEEE International Conference on Communications, ICC 2016 | Year: 2016

This paper investigates the power efficiency in downlink cooperative networks under spherical channel uncertainties, using a worst-case robust formulation. The aim of this paper is to jointly optimize the base station (BS) operation mode, mobile user (MU) association, and beamformings to achieve the robust network power gain. We formulate the problem as a mixed-integer non-convex problem with infinite number signal-to-interference-plus-noise ratio (SINR) and maximum transmit power constraints, which is nontrivial to solve even without this constraint. By firstly translating the uncertainty in CSI to the uncertainty in its covariance matrix, the SINR constraint spans a convex set using the Lagrangian based method. Due to the coupled integer variables, the complexity of exhaustive search grows exponentially with network size, motivating to develop low-complexity heuristic algorithms. We propose to solve the problem via a novel two-layer (TL) algorithm: inner and outer layer, successively. Specifically, the BS operation mode is determined successively in the outer layer using a Rank based Successive Search (RSS) method, while in the inner layer, an iterative Difference of Convex (DC) based algorithm is proposed to determine the MU association. Simulation results illustrate that the proposed algorithm can significantly reduce the total power consumption over existing alternatives. © 2016 IEEE.


Wang Y.,Harbin Institute of Technology | Liang B.,University of Toronto | Xu Y.,Harbin Institute of Technology | Xu Y.,Key Laboratory of Police Wireless Digital Communication
2016 IEEE International Conference on Communications, ICC 2016 | Year: 2016

This paper considers a downlink Coordinated Multi Point (CoMP) transmission network, where the base stations (BSs) are connected to a central unit via backhaul links to serve mobile users (MUs). The objective is to jointly optimize the BS mode (active or sleep), MU association, and cooperative beamforming to minimize the total power consumption including backhauling power. We formulate the problem as a mixed-integer non-convex problem under the constraints of signal-to-interference-plus-noise ratio (SINR) requirements and limited BS power. By exploiting a hidden convexity structure of the SINR, the problem is first transformed equivalently into a mixed-integer second-order core programming (MI-SOCP) problem. Due to the coupled integer variables, the complexity of exhaustive search grows exponentially with network size, which motivates developing low-complexity heuristic algorithms. We propose a novel Two-stage Rank Selection (TRS) method to approximately solve the coupled MI-SOCP problem by determining the BS operation mode and MU association successively, which enables the remaining beamforming computation to be achieved through an efficient SOCP solution. We compare the computational complexity and numerical performance of TRS against several state-of-the-art alternatives. Analytical and simulation results demonstrate that the proposed method can significantly reduce the computational complexity and the total power consumption over existing alternatives. © 2016 IEEE.


Kang J.,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

In this paper, problems in current heterogeneous networks are analyzed, such as too many parameters which make it hard to balance, ping-pong effect and handover dropping caused by frequent handover. Aiming at these problems, combining with parameters which are rarely considered intuitively in current multiple attribute decision making algorithms, a network handover trigger algorithm based on location information and a network selection algorithm based on DS evidence theory and analytic hierarchy process are proposed. On foundation of ensuring the quality of communication, the algorithm effectively controls the parameters which are used to assess the network handover. Simulation results verify the effectiveness of the algorithm. © 2014 IEEE.


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.

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