China Communications

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FEATURE TOPIC: COMMUNICATION IC

Research on CMOS Mm-Wave Circuits and Systems for Wireless Communications

JIA Haikun, CHI Baoyong, KUANG Lixue, YU Xiaobao, CHEN Lei, ZHU Wei, WEI Meng, SONG Zheng, WANG Zhihua

2015, 1(5): 1-13.

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This paper discusses some challenges in the design of millimeter-wave (mm-wave) circuits and systems for 5th generation (5G) wireless systems in CMOS process. The properties of some passive and active devices such as inductors, capacitors, transmission lines, transformers and transistors in mm-wave frequency band are discussed. Self-healing technique dealing with PVT variation, resonant mode switching technique to enhance frequency tuning range of voltage controlled oscillator (VCO) and dual mode technique for power amplifier (PA) efficiency enhancement are introduced. At last, A fully-integrated 60 GHz 5 Gb/s QPSK transceiver with the transmit/receive (T/R) switch in 65nm CMOS process is introduced. The measured error vector magnitude (EVM) of the TX is -21.9 dB while the bit error rate (BER) of the RX with a -52 dBm sine-wave input is below 8e-7 when transmitting/receiving 5 Gb/s data. The transceiver is powered by 1.0 V and 1.2 V supply (except the phase-frequency detector and charge-pump in the frequency synthesizer which are powered by 2.5 V supply) and consumes 135 mW in TX mode and 176 mW in RX mode.

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FEATURE TOPIC: COMMUNICATION IC

An 85mW 14-bit 150MS/s Pipelined ADC with a Merged First and Second MDAC

LI Weitao, LI Fule, YANG Changyi, LI Shengjing, WANG Zhihua

2015, 1(5): 14-21.

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A low-power 14-bit 150MS/s analog-to-digital converter (ADC) is presented for communication applications. Range scaling enables a maximal 2-Vp-p input with a single-stage opamp adopted. Opamp and capacitor sharing between the first multiplying digital-to-analog converter (MDAC) and the second one reduces the total opamp power further. The dedicated sample-and-hold amplifier (SHA) is removed to lower the power and the noise. The blind calibration of linearity errors is proposed to improve the performance. The prototype ADC is fabricated in a 130nm CMOS process with a 1.3-V supply voltage. The SNDR of the ADC is 71.3 dB with a 2.4 MHz input and remains 68.5 dB for a 120 MHz input. It consumes 85 mW, which includes 57 mW for the ADC core, 11 mW for the low jitter clock receiver and 17 mW for the high-speed reference buffer.

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FEATURE TOPIC: COMMUNICATION IC

Multilevel Power Modeling of Base Station and Its Ics

WANG Wei, LI Xiaoyang, LIU Dake, CAI Zhaoyun, GONG Chen

2015, 1(5): 22-33.

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A new power estimation method is proposed for base station (BS) in this paper. Based on this method, a software platform for power estimation is developed. The proposed method models power consumption on different abstraction levels by splitting a typical base station into several basic components at different levels in the view of embedded system design. In particular, our focus is on baseband IC (Integrate Circuit) due to it’s the dominant power consumer in small cells. Baseband power model is based on arithmetic computing costs of selected algorithms. All computing and storage costs are calibrated using algorithm complexity, hardware architecture, activity ratio, silicon technology, and overheads on all hierarchies. Micro architecture and IC technology are considered. The model enables power comparison of different types of base stations configured with different baseband algorithms, micro architectures, and ICs. The model also supports cellular operators in power estimation of different deployment strategies and transmission schemes. The model is verified by comparing power consumption with a real LTE base station. By exposing more configuration freedoms, the platform can be used for power estimation of current and future base stations.

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FEATURE TOPIC: COMMUNICATION IC

A Memory Efficient Belief Propagation Decoder for Polar Codes

SHA Jin, LIU Xing, WANG Zhongfeng, ZENG Xiaoyang

2015, 1(5): 34-41.

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Polar codes have become increasingly popular recently because of their capacity achieving property. In this paper, a memory efficient stage-combined belief propagation (BP) decoder design for polar codes is presented. Firstly, we briefly reviewed the conventional BP decoding algorithm. Then a stage-combined BP decoding algorithm which combines two adjacent stages into one stage and the corresponding belief message updating rules are introduced. Based on this stage-combined decoding algorithm, a memory-efficient polar BP decoder is designed. The demonstrated decoder design achieves 50% memory and decoding latency reduction in the cost of some combinational logic complexity overhead. The proposed decoder is synthesized under TSMC 45nm Low Power CMOS technology. It achieves 0.96 Gb/s throughput with 14.2mm² area when code length N=2¹⁶ which reduces 51.5% decoder area compared with the conventional decoder design.

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FEATURE TOPIC: COMMUNICATION IC

Low Power Sensor Design for IoT and Mobile Healthcare Applications

CHEN Xican, Woogeun RHEE, WANG Zhihua

2015, 1(5): 42-54.

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This paper reviews recent advances in radar sensor design for low-power healthcare, indoor real-time positioning and other applications of IoT. Various radar front-end architectures and digital processing methods are proposed to improve the detection performance including detection accuracy, detection range and power consumption. While many of the reported designs were prototypes for concept verification, several integrated radar systems have been demonstrated with reliable measured results with demo systems. A performance comparison of latest radar chip designs has been provided to show their features of different architectures. With great development of IoT, short-range low-power radar sensors for healthcare and indoor positioning applications will attract more and more research interests in the near future.

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CHANNEL CHARACTERIZATION AND MODELING

Frame Detection Based on Cyclic Autocorrelation and Constant False Alarm Rate in Burst Communication Systems

LIU Guangzu, WANG Jianxin, BAN Tian

2015, 1(5): 55-63.

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Frame detection is important in burst communication systems for its contributions in frame synchronization. It locates the information bits in the received data stream at receivers. To realize frame detection in the presence of additive white Gaussian noise (AWGN) and frequency offset, a constant false alarm rate (CFAR) detector is proposed through exploitation of cyclic autocorrelation feature implied in the preamble. The frame detection can be achieved prior to bit timing recovery. The threshold setting is independent of the signal level and noise level by utilizing CFAR method. Mathematical expressions is derived in AWGN channel by considering the probability of false alarm and probability of detection, separately. Given the probability of false alarm, the mathematical relationship between the frame detection performance and E_b/N₀ of received signals is established. Experimental results are also presented in accordance with analysis.

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CHANNEL CHARACTERIZATION AND MODELING

Capacity Maximization Based Power Loading Analysis for Digital Channelized Satcom Systems

YAN Jian, CHEN Xiang, LIU Chunli

2015, 1(5): 64-74.

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For digital channelized frequency division multiple access based satellite communication (SATCOM) systems, it is a challenging but critical issue to improve the transponder power and spectrum efficiency simultaneously under limited and non-linear high-power amplifier conditions. In this paper, different from the traditional link supportability designs aiming at minimizing the total transponder output power, a maximal sum Shannon capacity optimization objective is firstly raised subject to link supportability constraints. Furthermore, an efficient multilevel optimization (MO) algorithm is proposed to solve the considered optimization problem in the case of single link for each terminal. Moreover, in the case of multiple links for one terminal, an improved MO algorithm involving Golden section and discrete gradient searching procedures is proposed to optimize power allocation over all links. Finally, several numerical results are provided to demonstrate the effectiveness of our proposals. Comparison results show that, by the MO algorithm, not only all links’ supportability can be guaranteed but also a larger sum capacity can be achieved with lower complexity.

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COMMUNICATIONS SYSTEM DESIGN

Impact of Maximum Transmit Power Limit on the First-Order and Second-Order Performance of Cognitive Opportunistic Relaying

JIA Xiangdong, DENG Pengfei, ZHOU Ming, YANG Longxiang, ZHU Hongbo

2015, 1(5): 75-85.

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This paper focuses on the first-order and second-order performance of dual-hop underlay cognitive radio systems with opportunistic relaying (UCR-OR) over independent and non-identically distributed (i.ni.d) Rayleigh fading channels. For the UCR-OR systems, the tolerable maximum interference power (TMIP) Q at primary users (PUs) and the allowable maximum transmission power limit (AMTP) P_max at secondary users (SUs) are considered, simultaneously. We first obtain the closed-form solutions to the first-order performance such as outage probability, average symbol error ratio (SER), and ergodic capacity (EC). Secondly, we investigate the second-order statistical performance, i.e., average outage rate (AOR) and average outage duration (AOD). With the consideration that in practice implementation the receiver performance is primarily influenced by the signal-to-noise ratio (SNR) (not the signal envelope), the second-order statistical performance is investigated based on the equivalent instantaneous end-to-end SNR. Finally, we present the detailed performance comparison analysis of UCR-OR systems by defining a random variable μ=P_max/Q. The results show that the effect of μ on the first-order and second-order performances is different greatly. For the first-order performance, the performance gap is negligible when the value of μ is relatively large. However, for the second-order one, the gap is distinct.

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COMMUNICATIONS SYSTEM DESIGN

SHEN Lili, DU Weirong, WANG Cong, YUE Guanghui

2015, 1(5): 86-93.

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An approach to the direct measure of stereoscopic (3D) videos with different accelerations was presented, using electroencephalography (EEG). In the study, subjects viewed 1-sec-long video clips with a stone approaching straightforward and were required to perceive whether they were able to catch the outline of stone. Peak amplitude of each part was extracted from PO3 electrode located at the occipital region corresponding visual processing and cognition. Three components were conspicuously observed in the periods: 650-800 ms, 800-900 ms and 1150-1250 ms, which were called N310, N480 and N810 in this paper. N310 related to the perception to the initial stage of movement. Movement in-depth could be immediately perceived when initial speed was not less than 3 m/s. N480 related to the perception to acceleration/deceleration. N810 related to the perception to the point a movement was about to vanish. Subjects couldn’t perceive the outline with the final speed more than 3 m/s. For 3 m/s, subjects were in a dilemma to judge with the detecting rate 54%. Together, component analysis combined with behavioral results, it was supposed that 3 m/s to be the threshold to completely perceive the outline.

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NETWORK TECHNOLOGY AND APPLICATION

An Addressing and Routing Scheme Based on Modified Euclidean Space for Hexagonal Networks

GONG Jiezhong, LI Lin, CHEN Gongliang, WU Yue, LI Jianhua

2015, 1(5): 94-99.

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The addressing and routing algorithm on hexagonal networks is still an open problem so far. Although many related works have been done to resolve this problem to some extent, the properties of hexagonal networks are still not explored adequately. In this paper, we first create an oblique coordinate system and redefine the Euclidean space to address the hexagonal nodes. Then an optimal routing algorithm using vectors and angles of the redefined Euclidean space is developed. Compared with the traditional 3-directions scheme and the Cayley graph method, the proposed routing algorithm is more efficient and totally independent of the scale of networks with two-tuples addresses. We also prove that the path(s) obtained by this algorithm is always the shortest one(s).

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NETWORK TECHNOLOGY AND APPLICATION

Split-TCP Based Acceleration Gateway over Packet Lossy Networks

DONG Pingping, WANG Jianxin, HUANG Jiawei, WANG Haodong

2015, 1(5): 100-112.

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The conservative Additive Increase Multiplicative Decrease mechanism of traditional TCP causes the link under-utilization in the Wide Area Networks (WANs) due to the WANs’ intrinsic nature of high latency and high packet loss. To alleviate the problem, we present the design and implantation of STAG, an Acceleration Gateway with Split-TCP in the paper. STAG is built on embedded network equipment and acts as a transparent proxy. In STAG, a new improved congestion control method named Rapid TCP is adopted, which determines whether or not to decrease the congestion window based on the packet loss trend. In particular, in the fast recovery phase, it chooses different window adjustment strategies based on the current size of congestion window to achieve higher utilization. The performance validation of STAG is done on both our emulation testbed and the real wide area network. The results show that STAG with Rapid TCP effectively adapts to the high loss network environment and significantly speeds up the applications without loss of fairness.

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NETWORK TECHNOLOGY AND APPLICATION

A Universal Fairness Evaluation Framework for Resource Allocation in Cloud Computing

LU Di, MA Jianfeng, XI Ning

2015, 1(5): 113-122.

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In cloud computing, fairness is one of the most significant indicators to evaluate resource allocation algorithms, which reveals whether each user is allocated as much as that of all other users having the same bottleneck. However, how fair an allocation algorithm is remains an urgent issue. In this paper, we propose Dynamic Evaluation Framework for Fairness (DEFF), a framework to evaluate the fairness of an resource allocation algorithm. In our framework, two sub-models, Dynamic Demand Model (DDM) and Dynamic Node Model (DNM), are proposed to describe the dynamic characteristics of resource demand and the computing node number under cloud computing environment. Combining Fairness on Dominant Shares and the two sub-models above, we finally obtain DEFF. In our experiment, we adopt several typical resource allocation algorithms to prove the effectiveness on fairness evaluation by using the DEFF framework.

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STRATEGIES AND SCHEMES

HiQoS: An SDN-Based Multipath QoS Solution

YAN Jinyao, ZHANG Hailong, SHUAI Qianjun, LIU Bo, GUO Xiao

2015, 1(5): 123-133.

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Today’s Internet architecture provides only “best effort” services, thus it cannot guarantee quality of service (QoS) for applications. Software Defined Network (SDN) is a new approach to computer networking that separates control plane and forwarding planes, and has the advantage of centralized control and programmability. In this paper, we propose HiQoS that provides QoS guarantees using SDN. Moreover, HiQoS makes use of multiple paths between source and destination and queuing mechanisms to guarantee QoS for different types of traffic. Experimental results show that our HiQoS scheme can reduce delay and increase throughput to guarantee QoS. Very importantly, HiQoS recovers from link failure very quickly by rerouting traffic from failed path to other available path.

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STRATEGIES AND SCHEMES

An Orthogonal Approach to Reusable Component Discovery in Cloud Migration

ZHAO Junfeng, ZHOU Jiantao, YANG Hongji, LIU Guoping

2015, 1(5): 134-151.

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As an innovative software application mode, Software as a service (SaaS) shows many attractive advantages. Migrating legacy system to SaaS can make outdated systems revived. In the process of migration, the existing valuable components need to be discovered and reused in order that the target system could be developed/integrated more efficiently. An innovative approach is proposed in this paper to extract the reusable components from legacy systems. Firstly, implementation models of legacy system are recovered through reverse engineering. Secondly, function models are derived by vertical clustering, and then logical components are discovered by horizontal clustering based on the function models. Finally, the reusable components with specific feature descriptions are extracted. Through experimental verification, the approach is considered to be efficient in reusable component discovery and to be helpful to migrating legacy system to SaaS.

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SECURITY SCHEMES AND SOLUTIONS

Privacy-Preserving Relative Location Based Services for Mobile Users

Fei Ning, Zhuang Yi, GU Jingjing, Cao Jiannong, Yang Liang

2015, 1(5): 152-161.

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Location-aware applications have been used widely with the assistance of the latest positioning features in Smart Phone such as GPS, AGPS, etc. However, all the existing applications gather users’ geographical data and transfer them into the pertinent information to give meaning and value. For this kind of solutions, the user’s privacy and security issues might be raised because the geographical location has to be exposed to the service provider. A novel and practical solution is proposed in this article to provide the relative location of two mobile users based on their WiFi scanned results without any additional sensors. There is no privacy concern in this solution because end users will not collect and send any sensitive information to the server. This solution adopts a Client/Server (C/S) architecture, where the mobile user as a client reports the ambient WiFi APs and the server calculates the distances based on the WiFi AP’s topological relationships. A series of technologies are explored to improve the accuracy of the estimated distance and the corresponding algorithms are proposed. We also prove the feasibility with the prototype of “Circle Your Friends” System (CYFS) on Android phone which lets the mobile user know the distance between him and his social network friends.

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SECURITY SCHEMES AND SOLUTIONS

A Survey on the Privacy-Preserving Data Aggregation in Wireless Sensor Networks

XU Jian, YANG Geng, CHEN Zhengyu, WANG Qianqian

2015, 1(5): 162-170.

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Wireless sensor networks (WSNs) consist of a great deal of sensor nodes with limited power, computation, storage, sensing and communication capabilities. Data aggregation is a very important technique, which is designed to substantially reduce the communication overhead and energy expenditure of sensor node during the process of data collection in a WSNs. However, privacy-preservation is more challenging especially in data aggregation, where the aggregators need to perform some aggregation operations on sensing data it received. We present a state-of-the art survey of privacy-preserving data aggregation in WSNs. At first, we classify the existing privacy-preserving data aggregation schemes into different categories by the core privacy-preserving techniques used in each scheme. And then compare and contrast different algorithms on the basis of performance measures such as the privacy protection ability, communication consumption, power consumption and data accuracy etc. Furthermore, based on the existing work, we also discuss a number of open issues which may intrigue the interest of researchers for future work.

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