Shanghai Research Center for Wireless Communication

Shanghai, China

Shanghai Research Center for Wireless Communication

Shanghai, China
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Patent
Shanghai Research Center For Wireless Communication | Date: 2017-07-05

An uplink pilot sequence allocation method in a massive MIMO system is disclosed, the system including the master base station in the master cell and a neighboring base station in a neighboring cell, including: the neighboring base station comparing a primary eigen-space between a user group of the neighboring cell and the neighboring base station, with an interference eigen-space between a user group of the master cell close to the neighboring base station and the neighboring base station, and determining whether the user group of the neighboring cell can reuse uplink pilot sequence resources used by the user group of the master cell. In a manner of increasing information exchange, intercell cooperative uplink pilot sequence allocation is achieved, and uplink pilot contamination in a multi-cell massive MIMO system is reduced effectively.


Patent
Shanghai Research Center For Wireless Communication | Date: 2017-07-05

The present invention discloses an uplink resource scheduling method, and also discloses a corresponding terminal and base station. In the method, a base station calculates an uplink resource required to grant to a terminal by a base station according to a split bearer data ratio, and then performs uplink resource grant.


Patent
Shanghai Research Center For Wireless Communication | Date: 2017-08-09

The present invention discloses an uplink resource sharing method, base station and terminal, wherein, the uplink resource sharing method comprises: performing the LBT on a granted subframe, allocated to a terminal by a base station, by the terminal; transmitting data if the LBT is finished on the granted subframe; and performing the LBT on another subframe if the LBT is not finished on the granted subframe. The present invention solves the problem of resource waste caused by the fact that the terminal cannot finish LBT in a frame allocated to the frame by a base station, and reduces a probability of increase of an uplink grant number caused by failing of uplink scheduling.


Patent
Shanghai Research Center For Wireless Communication | Date: 2017-06-07

A coordination method between access points using unlicensed frequency bands and a network control node using this method are disclosed. The method includes: the first access points adjusting transmission parameters thereof to increase channel access probability of the first access points; and the second access points adjusting transmission parameters thereof to decrease the channel access probability of the second access points; wherein the degree to which channel access probability of the third access points is decreased due to adjustment of the transmission parameters of all the first access points is equivalent to the degree to which the channel access probability is increased due to adjustment of the transmission parameters of all the second access points. Through coordination between multiple access points in the same network, fair coexistence with other networks using unlicensed frequency bands can be ensured while user QoS is improved.


Fang W.,CAS Shanghai Institute of Microsystem and Information Technology | Zhang W.,CAS Shanghai Institute of Microsystem and Information Technology | Zhang W.,Shanghai Research Center for Wireless Communication | Yang Y.,CAS Shanghai Institute of Microsystem and Information Technology | And 4 more authors.
Science China Information Sciences | Year: 2017

Compared with the encryption and the authentication which can prevent the external attacks, the trust management schemes are the better approaches for defending against the internal attacks in wireless sensor network (WSN). The reputation time-varying (RTV) attacks are internal attacks. In the reputation time-varying attacks, the reputation value of nodes is manipulated to adjust dynamically by the compromised nodes or malicious attackers. Hence, these attacks have greater covert and invasive. In this paper, we propose a Time-window-based Resilient Trust Management Scheme (TRTMS) to defend against the reputation time-varying attacks in wireless sensor network. In this scheme, based on BETA distribution, the behaviors of compromised nodes are analyzed for a period of time, and then the difference judgment and the trend analysis are utilized to identify the abnormality of nodes’ reputation value, meanwhile, the control factor Fc and the time window are introduced to verify and remove the compromised modes from the suspected malicious nodes, which refer to those nodes’ reputation value changes are caused by the wireless channel changes. The result of simulation shows that our proposed scheme can defend reputation time-varying attacks effectively and it is convenient to implement. © 2017, Science China Press and Springer-Verlag Berlin Heidelberg.


Jia B.,University of Shanghai for Science and Technology | Jia B.,Shanghai Research Center for Wireless Communication | Jia B.,CAS Shanghai Institute of Microsystem and Information Technology | Hu H.,Shanghai Research Center for Wireless Communication | And 4 more authors.
2016 IEEE Global Communications Conference, GLOBECOM 2016 - Proceedings | Year: 2016

In this paper, we investigate the user pairing scheme in virtual multiple-input multiple-output (V- MIMO) systems, which can significantly improve system performance and spectral efficiency (SE) using multiuser diversity. Considering the development of green communication, we want to find the upper bound of energy efficiency (EE) under the constraint of SE. Firstly, the optimal transmit power allocation for the optimal EE under the constraint of SE is formulated as a non-convex optimization problem and a novel projective constraint analysis (PCA) is devised for it. Then, we reveal the maximum EE and the corresponding transmit power allocation in the global solution space. According to the location relationship between the maximum EE and the constraint of SE, we propose a spatial approach based on PCA to pursue the upper bound of EE with two different cases. Finally, a novel PCA-based user pairing scheme achieving the upper bound of EE under the constraint of SE is proposed. Numerical results illustrate the impact of different system parameters for the upper bound of EE and prove that the proposed PCA-based iteration algorithm has much lower complexity than the global search approach. © 2016 IEEE.


Zhao C.,CAS Shanghai Institute of Microsystem and Information Technology | Zhao C.,Shanghai Research Center for Wireless Communication | Zhang W.,CAS Shanghai Institute of Microsystem and Information Technology | Zhang W.,Shanghai Research Center for Wireless Communication | And 5 more authors.
IEEE Transactions on Vehicular Technology | Year: 2015

Compressive sensing (CS)-based data aggregation has become an increasingly important research topic for largescale wireless sensor networks since conventional data aggregations are shown to be inefficient and unstable in handling huge data traffic. However, for CS-based techniques, the discrete cosine transform, which is the most widely adopted sparsification basis, cannot sufficiently sparsify real-world signals, which are unordered due to random sensor distribution, thus weakening advantages of CS. In this paper, an energy-efficient CS-based scheme, which is called "treelet-based clustered compressive data aggregation" (T-CCDA), is proposed. Specifically, as a first step, treelet transform is adopted as a sparsification tool to mine sparsity from signals for CS recovery. This approach not only enhances the performance of CS recovery but reveals localized correlation structures among sensor nodes as well. Then, a novel clustered routing algorithm is proposed to further facilitate energy saving by taking advantage of the correlation structures, thus giving our T-CCDA scheme. Simulation results show that the proposed scheme outperforms other reference approaches in terms of communication overhead per reconstruction error for adopted data sets. © 2014 IEEE.


Han T.,Huazhong University of Science and Technology | Liu X.,Huazhong University of Science and Technology | Wang L.,Wenhua College | Wang J.,Shanghai Research Center for Wireless Communication | And 3 more authors.
2016 IEEE International Conference on Communications, ICC 2016 | Year: 2016

This paper investigates the energy saving of base station (BS) deployed in a 1-D multi-hop vehicular network with sleep scheduling strategy. We consider cooperative BS scheduling strategy where BSs can switch between sleep and active modes to reduce the average energy consumption utilizing the information of vehicular speeds and locations. Assuming a Poisson distribution of vehicles, we derive an appropriate probability distribution function of distance between two adjacent cluster heads, where a cluster is a maximal set of vehicles in which every two adjacent vehicles can communicate directly when their Euclidean distance is less than or equal to a threshold, known as the communication range of vehicles. Furthermore, the expected value of the sojourn time in the sleep mode and energy saving are obtained. The numerical results show that the sleep scheduling strategy significantly reduces the energy consumption of the base stations.1 © 2016 IEEE.


Han T.,Huazhong University of Science and Technology | Feng Y.,Huazhong University of Science and Technology | Wang J.,Shanghai Research Center for Wireless Communication | Wang J.,CAS Shanghai Institute of Microsystem and Information Technology | And 3 more authors.
2015 IEEE International Conference on Communication Workshop, ICCW 2015 | Year: 2015

In this paper, we consider a two-dimensional heterogeneous cellular network scenario consisting of one base station (BS) and some mobile stations (MSs) whose locations follow a Poisson point process (PPP). The MSs are equipped with multiple radio access interfaces including a cellular access interface and at least one short-range communication interface. We propose a nearest-neighbor cooperation communication (NNCC) scheme by exploiting the short-range communication between a MS and its nearest neighbor to collaborate on their uplink transmissions. In the proposed cooperation scheme, a MS and its nearest neighbor first exchange data by the short-range communication. Upon successful decoding of the data from each other, they proceed to send their own data, as well as the data received from the other to the BS respectively in orthogonal time slots. The energy efficiency analysis for the proposed scheme is presented based on the characteristics of the PPP and the Rayleigh fading channel. Numerical results show that the NNCC scheme significantly improves the energy efficiency compared to the conventional non-cooperative uplink transmissions. © 2015 IEEE.


Patent
Shanghai Research Center For Wireless Communication | Date: 2016-11-30

Disclosed is a network frequency spectrum sharing method, which is used for implementing shared frequency spectrum allocation between a present operator and a different operator. In a certain area, a user terminal of the present operator performing signal strength measurement of the different operator and sending a network signal strength measurement report of the different operator to a home base station; the operation management node of the given operator, based on the network signal strength measurement report of the different operator, which is forwarded by the base station, calculating a network overlapping degree indication of the different operator, and based on the network overlapping degree indication, obtaining network overlapping topology-based information of the different operator; and a present operator network and a different operator network exchanging the network overlapping topology-based information, and calculating a policy for allocating shared spectrum resources between the present operator and the different operator. The present invention can enable different operators to fairly and reasonably share frequency spectrum resources within a specified range, thus increasing a frequency spectrum utilization rate of an entire communication network and ensuring communication quality of the user terminal.

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