Repair the faulty TSVs with the improved FNS-CAC codec

Through-silicon via (TSV) is a key enabling technology for the emerging 3-dimension (3D) integrated circuits (ICs). However, the crosstalk between the neighboring TSVs is one of the important sources of the soft faults. To suppress the crosstalk, the Fibonacci-numeral-system-based crosstalk avoidance code ( FNS-CAC) is an effective scheme. Meanwhile, the self-repair schemes are often used to deal with the hard faults, but the repaired results may change the mapping between signals to TSVs, thus may reduce the crosstalk suppression ability of FNS-CAC. A TSV self-repair technique with an improved FNS-CAC codec is proposed in this work. The codec is designed based on the improved Fibonacci numeral system (FNS) adders, which are adaptive to the health states of TSVs. The proposed self-repair technique is able to suppress the crosstalk and repair the faulty TSVs simultaneously. The simulation and analysis results show that the proposed scheme keeps the crosstalk suppression ability of the original FNS-CAC, and it has higher reparability than the local self-repair schemes, such as the signal-switching-based and the signal-shifting-based counterparts.     

Scalable connection-based flow control scheme for application-specific network-on-chip

In this paper,a scalable connection-based flow control scheme is proposed for application-specific network-on-chip(NoC).The proposed scheme exploits two distinctive characteristics of NoC,namely traffic predictability and abundant wire resource,to achieve significant performance enhancements.First,the burst injection data are regulated into constant data streams and a connection-based method is used to ensure that all links are not overloaded at any time.Consequently,the number of packets in the network is decreased,leading to a reduced congestion probability and improved communication performance.Second,a simple architecture of the central controller is proposed to guarantee that the proposed scheme has small area overhead and is scalable.Simulation results show that compared with traditional switch-to-switch(STS) flow control scheme and pre-allocation based flow control schemes,the proposed scheme greatly increases the throughput and cuts down the average latency with reasonable area and energy overhead.     

A delay based backoff scheme for WLAN with QoS guarantee and its performance

Based on the Distributed Coordination Function (DCF) and the Enhanced DCF (EDCF) mechanisms in IEEE 802.11 and 802.11e, a novel backoff scheme for Wireless Local Area Network (WLAN) is proposed. The scheme is to solve the problem of the packet loss and the decrease of performance due to the increasing Contention Window (CW) when there are continuous collisions. In the proposed scheme, the CW of the packet will change dynamically with different delay for the different traffics. Mathematic formulas are presented to indicate the relationship between the CW and the delay character. The performance of the new scheme is also discussed with simulation results. The results show that it helps WLAN system handle multimedia simultaneously.     

Asynchronous diversity receiving scheme and analysis on cooperative relay networks简

The transmission antennas of cooperative systems are spatially distributed on multiple nodes, so the received signal can be asynchronous due to propagation delays. A receiving scheme for cooperative relay networks is proposed, multiple asynchronous signals are reconstructed at the receiver by forward and backward interference cancellation, which can obtain gains of cooperative transmission diversity with obvious delay and with no requiring timing synchronization or orthogonal channelization between relays. Analysis and simulation show that the bit error rate（BER） of the proposed scheme is similar to Alamouti code, and the scheme has the diversity order of orthogonal transmission scheme accompanied by minimal BER losses. It is demonstrated that the performance can be further improved by adding an error correcting code（ECC）.     

Defense against collusion scheme based on elliptic curve cryptography for wireless sensor networks

Wireless Sensor Networks (WSNs) are being deployed for a wide variety of applications and the security problems of them have received considerable attention. Considering the limitations of power, com-putation capability and storage resources, this paper proposed an efficient defense against collusion scheme based on elliptic curve cryptography for wireless sensor networks in order to solve the problems that sensor node-key leaking and adversaries make compromised nodes as their collusions to launch new attack. In the proposed scheme, the group-key distribution strategy is employed to compute the private key of each sensor node, and the encryption and decryption algorithms are constructed based on Elliptic Curve Cryptography (ECC). The command center (node) only needs to broadcast a controlling header with three group elements, and the authorized sensor node can correctly recover the session key and use it to decrypt the broadcasting message. Analysis and proof of the proposed scheme’s efficiency and security show that the proposed scheme can resist the k-collusion attack efficiently.     

Particle filtering based channel estimation in OFDM power line communication

Particle filtering （PF） algorithm has the powerful potential for coping with difficult non-linear and non-Gaussian problems. Aiming at non-linear, non-Gaussian and time-varying characteristics of power line channel, a time-varying channel estimation scheme combined PF algorithm with decision feedback method is proposed. In the proposed scheme, firstly the indoor power line channel is measured using the pseudo-noise （PN） correlation method, and a first-order dynamic autoregressive （AR） model is set up to describe the measured channel, then, the channel states are estimated dynamically from the received signals by exploiting the proposed scheme. Meanwhile, due to the complex noise distribution of power line channel, the performance of channel estimation based on the proposed scheme under the Middleton class A impulsive noise environment is analyzed. Comparisons are made with the channel estimation scheme respectively based on least square （LS）, Kalman filtering （KF） and the proposed algorithm. Simulation indicates that PF algorithm dealing with this power line channel estimation difficult non-linear and non-Gaussian problems performance is superior to those of LS and KF respectively, so the proposed scheme achieves higher estimation accuracy. Therefore, it is confirmed that PF algorithm has its own unique advantage for power line channel estimation.     

Securing Cloud Data Using a Pirate Scheme

Inspired by the approach of smart pirates dealing with their treasures, the paper proposed a scheme to protect the data security and privacy in cloud computing. In the proposed scheme, cloud data will be divided into some sequenced or logical blocks. These data blocks will be distributed among cloud storage service providers. Instead of protecting the data themselves, the proposed scheme protects the mapping of the data elements on each provider. Comprehensive analysis and simulation are designed to verify the proposed scheme, the results show that it is secure for cloud data, and the real implementation on Amazon S3 also indicates that the proposed scheme is feasible and efficient for the cloud data storage.     

EKAES: An efficient key agreement and encryption scheme for wireless sensor networks

Wireless sensor networks are being deployed for some practical applications and their security has received considerable attention.It is an important challenge to find out suitable key agreement and encryption scheme for wireless sensor networks due to limitations of the power,computation capability and storage resources.In this paper,an efficient key agreement and encryption scheme for wireless sensor networks is presented.Results of analysis and simulations among the proposed scheme and other schemes show that the proposed scheme has some advantages in terms of energy consumption,computation requirement,storage requirement and security.     

A STUDY ON PROBE-BASED MULT1CAST ADMISSION CONTROL AND ENHANCEMENT

To provide scalable and simple Quality of Service（QoS） mechanism for multicast services, Probe-Based Multicast Admission Control （PBMAC） scheme was proposed. In this paper, PBMAC is studicd and a so-called subsequent request problem is found in PBMAC, which degrades system performance significantly when the network traffic is heavily loaded. Based on the analysis on subsequent request problem, an Enhance PBMAC （EPBMAC） scheme is proposed, in which complementary probing is devised to solve the problem. Using a new metric of normalized requested equivalent link capacity, the pertbrmance of PBMAC and EPBMAC is analyzed and evaluated. Two implementations are proposed for incremental dcployment. The paper finally introduces evaluation with packet-based simulations. Both analytical and simulation results show the significant improvement in performance.     

A UNIVERSAL RECEIVER STRUCTURE FOR MDPSK SIGNALS

In this letter,a universal receiver structure with modu7lation classification and synchronization recovery for MDPSK signal is presented.The universal timing estimation algorith for M-ary DPSK signals is proposed to estimaate the best symbol timing.An identification algorithm based on fourth-order cumulants of signal is used to identify the modulation scheme of the signal.Numerical results of the preformance of the proposed receiver are given.     

自适应映射广义空移健控调制(英文)

Generalized Space Shift Keying (GSSK) modulation is a low-complexity spatial multiplexing technique for multiple-antenna wireless systems. However, effective transmit antenna combinations have to be preselected, and there exist redundant antenna combinations which are not used in GSSK. In this paper, a novel adaptive mapping scheme for GSSK modulation, named as Adaptive Mapping Generalized Space Shift Keying (AMGSSK), is presented. Compared with GSSK, the antenna combinations are updated adaptively according to the Channel State Information (CSI) in the proposed AMGSSK system, and the performance of average Symbol Error Rate (SER) is reduced considerably. In the proposed scheme, two algorithms for selecting the optimum antenna combinations are described. The SER performance of AMGSSK is analyzed theoretically, and validated by Monte Carlo simulation. It is shown that the proposed AMGSSK scheme has good performance in SER and spectral efficiency.     

Hybrid redundancy approach to increase the reliability of FPGA based speed controller core for high speed train

With the progress of the railway technology, the railway transportation is becoming more efficient, intelligent and faster. High speed trains, as a major part of the railway transportation, are engaged with passenger＇s safety, and therefore the reliability issue is very important in such vital systems. In this paper, a dependable speed controller core based on FPGA has been developed for high speed trains. To improve the reliability and mitigate single upset faults on basic speed controller, this paper proposes a new effective method which is based on hardware redundancy. In the proposed Hybrid Dual Duplex Redundancy （HDDR） method, the original controller is quadruplicated and correct values are voted through the comparator and error detection unit. We have analyzed the proposed system with Reliability, Availability, Mean time to failure and Security （RAMS） theory in order to evaluate the effectiveness of proposed scheme. Theoretical analysis shows that the Mean Time To Failure （MTTF） of the proposed system is 2.5 times better than the traditional Triple Modular Redundancy （TMR）. Furthermore, the fault injection experimental results reveal that the capability of tolerating Single Event Upsets （SEUs） in the proposed method increases up to 7.5 times with respect to a regular speed controller.     

Research on uplink coordinated transmission schemes in LTE-advanced systems

The investigation of inter-cell interference mitigation techniques is a key area in wireless communications.Coordinated multiple points(CoMP) transmission/reception is a candidate technique for interference cancellation in 3GPP LTE-Advanced system.However,the coordination scheme in CoMP remains a key research problem to be solved,which will have a strong influence on the performance of CoMP.In this paper,a novel coordinated transmission scheme is proposed for the uplink LTE-Advanced system.In our scheme,several base transceiver stations(BTS) and users are selected as coordination partners which form a CoMP cluster.Joint processing is used at the receiver to mitigate interference.From the perspective of coordinated partner selection,our scheme can be divided into static and dynamic coordination which are both considered to fully exploit the throughput gain of CoMP.The proposed schemes are evaluated by system level simulation and compared with the conventional LTE system based upon single cell processing.Our simulation results demonstrate that the proposed schemes attain superior performance as opposed to the conventional system in terms of cell average and cell edge throughput.     

Interleaving scheme for multicarrier CDMA system

In MultiCarrier Code-Division Multiple-Access (MC-CDMA) system,the received signals scattered in the frequency domain are combined to get frequency diversity gain.However,the frequency diversity gain is limited because of correlation between subcarriers.A novel interleaving scheme for MC-CDMA system is proposed in this paper.A circular shifting register is introduced into each subcarrier branch to decrease the correlation between subcarriers.By using interleaving,frequency diversity gain of system is increased.System structure and model with interleaver are discussed.In the case of multiple users,Parallel Interference Cancellation (PIC) technique is also introduced.Computer simulations demonstrate the performance of proposed scheme,and the performance comparison of MC-CDMA with interleaver and conventional MC-CDMA system is shown as well.     

Low complexity power allocation for hybrid amplify-and-forward opportunistic relay ordering cooperation

In this paper, to enhance the robustness against link imbalance, a hybrid cooperative protocol is proposed for amplify-and-forward （AF） opportunistic cooperation, where opportunistic relaying and multi-hop cooperation with relay ordering （RO） are dynamically selected to maximize the end to end signal-noise ratio （SNR）, and the power allocation coefficient is optimized under total power constraint accordingly. Furthermore, a suboptimum allocation scheme with low complexity is proposed by employing the upper bound of harmonic mean. Simulation results show that the proposed scheme outperforms conventional AF opportunistic cooperation in variety of line type topology. Moreover, the efficiency of the proposed suboptimum allocation is also validated in large SNR region.     

Optimal Test Points Selection Based on Multi-Objective Genetic Algorithm

A new approach to select anoptimal set of test points is proposed. The described method uses fault-wise table and multi-objective genetic algorithm to find the optimal set of test points. First, the fault-wise table is constructed whose entries are measurements associated with faults and test points. The selection of optimal test points is transformed to the selection of the columns that isolate the rows of the table. Then, four objectives are described according to practical test requirements. The multi-objective genetic algorithm is explained. Finally, the presented approach is illustrated by a practical example. The results indicate that the proposed method can efficiently and accurately find the optimal set of test points and is practical for large scale systems.     

Dynamic bias setting for range extension in LTE-advanced macro-pico heterogeneous networks

In co-channel deployment of macro cell and pico cells, cell range extension （RE）, a simple and typical cell association scheme, is introduced to achieve better load balancing and improve cell edge performance. In this article, a novel dynamic and distributed bias setting scheme is proposed for RE technique in macro-pico heterogeneous networks. In this strategy, the worst user throughput of each cell during an adjusting time interval T is obtained to change the bias values according to certain procedures, where an introduced indicator is used to freeze the possibility of increasing bias value if needed. Furthermore, silent state and coarse control process are employed to achieve low overheads and computational complexity. Simulation results show that the proposed scheme can greatly improve the cell-edge performance compared with the static bias setting strategies, while maintaining the overall cell performance at the same time.     

An improved scheme for passive synthetic aperture photonic imaging

An improved scheme for passive synthetic aperture imaging is proposed. With this new technique, the radiation signal from field of view （FOV） is received and its frequency is down-converted to intermediate frequency （IF）. The IF signals are modulated to light-wave by electro-optical phase modulators and transmitted in fiber. At the end of the fiber, a downscaled fiber array is formed according to the receiver array. The image of FOV is obtained with the fiber array. The principles of passive synthetic aperture photonic imaging technique are analyzed deeply and its properties are compared with traditional imaging method of synthetic aperture. By simulation, the spread function of spot source and the image signal-noise-ratio are investigated using the new imaging approach with FOV radiation from different incidence angles. The introduced scheme can reconstruct the target image and perfect the present synthetic aperture imaging systems.     

United stabilizing scheme for edge delay in optical burst switched networks

A novel scheme, namely united stabilizing scheme for edge delay, is introduced in optical burst switched networks. In the scheme, the limits of burst length and assembly time are both set according to certain qualifications. For executing the scheme, the conception for unit input bit rate is introduced to improve universality, and the assembly algorithm with a buffer safety space under the self-similar traffic model at each ingress edge router is proposed. Then, the components of burst and packet delay are concluded, and the equations that limits of burst length and assembly time should satisfy to stabilize the burst edge delay under different buffer offered loads are educed. The simulation results show that united stabilizing scheme stabilizes both burst and packet edge delay to a great extent when buffer offered load changes from 0.1 to 1, and the edge delay of burst and packet are near the limit values under larger offered load, respectively.     

QoS-Aware Dynamic Resource Management in Heterogeneous Mobile Cloud Computing Networks

In mobile cloud computing（MCC） systems,both the mobile access network and the cloud computing network are heterogeneous,implying the diverse configurations of hardware,software,architecture,resource,etc.In such heterogeneous mobile cloud（HMC） networks,both radio and cloud resources could become the system bottleneck,thus designing the schemes that separately and independently manage the resources may severely hinder the system performance.In this paper,we aim to design the network as the integration of the mobile access part and the cloud computing part,utilizing the inherent heterogeneity to meet the diverse quality of service（QoS）requirements of tenants.Furthermore,we propose a novel cross-network radio and cloud resource management scheme for HMC networks,which is QoS-aware,with the objective of maximizing the tenant revenue while satisfying the QoS requirements.The proposed scheme is formulated as a restless bandits problem,whose ＂indexability＂ feature guarantees the low complexity with scalable and distributed characteristics.Extensive simulation results are presented to demonstrate the significant performance improvement of the proposed scheme compared to the existing ones.