National Digital Switching System Engineering Technical Researching Center

Zhengzhou, China

National Digital Switching System Engineering Technical Researching Center

Zhengzhou, China
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Qi W.,National Digital Switching System Engineering Technical Researching Center
IEEE Transactions on Information Theory | Year: 2017

Grain-128 is a hardware oriented stream cipher based on the cascade connection of a 128-bit LFSR into a 128-bit quadratic NFSR. Its main register is in essence a quadratic NFSR, however its affine sub-families could not be solved by previous methods. In this paper, it is shown that the family of sequences generated by the main register of Grain-128 includes no affine sub-families except a small one of order 3. To achieve this goal, a new method is proposed for solving affine sub-families of general quadratic NFSRs. Let NFSR(f) be an NFSR with a quadratic characteristic function f. It is proved that the characteristic function of a linear sub-family of the NFSR(f) divides a linear combination of variables appearing in the quadratic terms of f, where the division can be seen as the univariate polynomial division over the finite field F2. This facilitates picking up a candidate set of linear sub-families through univariate polynomial factorization over F2. The affine case is an analogy. Besides, a useful new upper bound on the orders of affine sub-families of a quadratic NFSR is given. IEEE


Wang C.,National Digital Switching System Engineering Technical Researching Center | Tang J.,Tsinghua University
Multidimensional Systems and Signal Processing | Year: 2017

A novel feedback beamformer is proposed for receiving multipath coherent signals. First, a subtraction-based minimum variance distortionless response beamformer is utilized to obtain an estimation of the desired signal. Then its output is fed back to the original full aperture array where a minimum mean square error (MMSE) beamformer is applied. Due to multipath-matched feature of the MMSE beamformer, the novel feedback beamformer can combine multipath signals without aperture loss. Two feedback schemes are proposed and their effectiveness is verified via simulation. © 2017 Springer Science+Business Media, LLC


Xingbao W.,National Digital Switching System Engineering Technical Researching Center | Wu J.,National Digital Switching System Engineering Technical Researching Center
2016 2nd IEEE International Conference on Computer and Communications, ICCC 2016 - Proceedings | Year: 2017

A measurement-driven probability hypothesis density (MD-PHD) filter based on track initiation is proposed in this paper to handle the incapability of PHD filter when dealing with unknown newborn intensity. Measurements are distinguished into two parts by using gating technology. The existing measurements are used to update intensity while the suspicious measurements are utilized to explore new target via track initiation. The sequential Monte Carlo (SMC) implementation of the proposed filter is derived and applied to passive scenario. The simulation results demonstrate that the proposed method not only tracks existing target accurately but also initiates new target duly without any prior knowledge of newborn intensity. © 2016 IEEE.


Li P.,National Digital Switching System Engineering Technical Researching Center | Yang Y.,National Digital Switching System Engineering Technical Researching Center
2016 2nd IEEE International Conference on Computer and Communications, ICCC 2016 - Proceedings | Year: 2017

In this paper, we consider a multi-layer visible light communication system where data of different attribute are split into multiple layers with different bit rates and reliability to satisfy data transmission in priorities. In proposed approach, high-priority data is assigned to upper layers with higher reliability through high diversity, while low-priority data is assigned to lower layers with higher bit rates through high multiplexing. In addition, two detection algorithms are presented for fast decoding: one is low-complexity sum detection, the other is fast maximum likelihood detection. Simulation shows that maximum likelihood (ML) detection has more excellent performance and higher computation complexity than sum detection in general, while both algorithms have similar performance when upper layers obtain sufficient power. © 2016 IEEE.


Hu C.,Xi'an Jiaotong University | Wu C.,Zhejiang University | Xiong W.,Zhejiang University | Wang B.,National Digital Switching System Engineering Technical Researching Center | And 2 more authors.
IEEE Communications Magazine | Year: 2011

A great deal of research has contributed to the energy efficiency of battery-operated devices in the area of wireless communications, but recently, the energy consumption of the underlying network infrastructure has started to attract more attention as people have become aware of the significant fraction of energy consumed by the Internet of all the energy we consume. We argue that the architecture of routers in constructing the Internet can be improved so as to fully utilize chances to save energy related to transmission equipment. A green reconfigurable router is thus presented for this purpose. © 2011 IEEE.


Patent
Shanghai RedNeurons Co. and National Digital Switching System Engineering Technical Researching Center | Date: 2016-02-08

The present invention discloses a software/hardware device with uncertain service function and structural characterization and a method for scheduling the same. The device comprises a policy generator, a scheduler and a plurality of heterogeneous functional equivalents with equivalent functions, wherein, the policy generator is configured for providing a scheduling policy for the heterogeneous functional equivalents to the scheduler; the scheduler is configured for receiving an external service request, determining heterogeneous functional equivalents that provide a service to the external service request according to the scheduling policy given by the policy generator, assigning the service request to the determined heterogeneous functional equivalents, and outputting a service response which has an uncertain relation with uncertain structural characterization according to a feedback and the scheduling policy given by the policy generator. Therefore, the service response provided to the service request has an uncertain correspondence relation with feedback results of the heterogeneous functional equivalents of the device, so that the effectiveness of detection or attack on an unknown loophole, trapdoor of the device is greatly lowered, and the protective ability of the software/hardware device is enhanced.


Wang W.-Y.,National Digital Switching System Engineering Technical Researching Center | Zhu Y.-J.,National Digital Switching System Engineering Technical Researching Center
IEEE Photonics Journal | Year: 2016

In this paper, a multiple light-emitting diode (LED) collaborated signal design based on amplitude-phase superposition (MLC-APS) for multi-input single-output visible light communication (VLC) systems is proposed. By using the additive unique factorization technique, all the LED chips can be viewed as transmitting in parallel to increase the rate of VLC systems. In the MLC-APS system, each LED adopts on-off-keying (OOK) modulation, and therefore, the influences of peak-to-average power ratio and clipping are reduced significantly. Simulation results show its significant error performance gains over the direct-current-biased optical orthogonal frequency division multiplexing (OFDM) system. © 2016 IEEE.


Lan J.-L.,National Digital Switching System Engineering Technical Researching Center | Cheng D.-N.,National Digital Switching System Engineering Technical Researching Center | Hu Y.-X.,National Digital Switching System Engineering Technical Researching Center
Tongxin Xuebao/Journal on Communications | Year: 2014

Based on the thinking of network reconfiguration, the reconfigurable information communication basal network architecture was proposed, and then the network atomic capacity theory, polymorphic addressing and routing mechanism, network reconfiguration mechanism and the secure manageability and controllability mechanism were put forward respectively. The architecture would provide a resolution for current and future applications with different quality of services, flexible and expansible function, universal inter-connection, heterogeneous convergence, manageability and controllability, which also supports the compatible evolution with current internet and is feasible to be implemented on a large scale.


Luo W.,National Digital Switching System Engineering Technical Researching Center
IEEE Wireless Communications and Networking Conference, WCNC | Year: 2013

The unstable characteristic of ill-conditioned system is used to guarantee wireless security in this paper. The use of ill-conditioned theory to protect wireless transmissions is proposed as a way to secure wireless networks at physical layer. Firstly, the problem of randomized transmission is converted to that of solving ill-conditioned equation to guarantee wireless transmissions with inherent low-probability-of interception (LPI). Secondly, a conditional ill-conditioned optimization function is constructed. The function of legitimate node is stable because of its matched channel. But the function of eavesdropper is randomized because that she has not the legitimate conditions, which relate to the wireless medium contains domain-specific information. In this context, we propose a security scheme for wireless security in time-variant channels. In this scheme, the variable part of channels is converted to additional conditions, which can be solved by optimizing parameters. In contrast to conventional physical-layer security techniques, the scheme exploits the redundancy of ill-conditioned problem's solutions instead of array redundancy for deliberate signal randomization, which effectively randomizes the eavesdropper's received signals but not the authorized receiver's signals. Extensive simulations and analysis results show that our proposed scheme is useful for securing wireless transmissions. © 2013 IEEE.


Yang T.C.,National Digital Switching System Engineering Technical Researching Center | Jin L.,National Digital Switching System Engineering Technical Researching Center
Science China Information Sciences | Year: 2011

This paper proposes an algorithm, called circle fitting algorithm, for locating targets by using maneuverable single station in non-line-of-sight environment. This algorithm estimates the position and scattering distance of all scatters based on the circular motion character. The pseudo-target trajectory is calculated from observation results from different observation positions. With scatters regarded as virtual observation stations, the problem of single station location can be converted into a problem of multi-station location. Finally, the traditional multi-station location algorithm is used to estimate target position. Simulation results prove that the proposed method is effective. © Science China Press and Springer-Verlag Berlin Heidelberg 2010.

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