Iterative Clustering for Energy-Efficient Large-Scale Tracking Systems

Wireless Personal Communications - A new technique is presented to design energy-efficient large-scale tracking systems based on mobile clustering. The new technique optimizes the formation of...     

Energy-Efficient Power Allocation with Hybrid Beamforming for Millimetre-Wave 5G Massive MIMO System

Wireless Personal Communications - Massive multiple-input and multiple-output systems combined with hybrid beamforming technique is a key approach to achieve high data rate and extended cell...     

一种有效的智能天线波束成形技术

提出了一种新的智能天线算法,这种算法结合了多用户联合检测技术和RAKE接收技术,具有较小的运算量和良好的误码率性能,仿真的结果也证明了这是一种可行的方法,特别是在大的用户数目的情况下,智能天线的性能要远远好于一般的阵列天线的性能。     

基于累积量的极化敏感阵列信号DOA和 极化参数的同时估计

本文研究极化敏感阵列非高斯窄带信号二维波达方向(DOA)和极化参数的同时估计问题.所考虑的极化敏感阵列包含一个特定子阵,该子阵由空间稀疏伸展三极子天线和两个导引阵元组成.分析了3维极化-角度域相干结构的平凡模糊问题,对利用并行累积量ESPRIT分别恢复出的信号3维极化-角度域相干结构和空域相干结构信息进行联合完成了非线性极化信号二维DOA和极化参数的同时估计.给出了一种相位缠绕解决方案并讨论了空间伸展三极子天线的可选择结构.     

数字波束形成雷达的天线方向图预置零技术

基于数字波束形成体制的相控阵雷达系统,如果杂波和干扰的角度先验信息可以获知,则可采用方向图预置零技术进行相关的抑制处理。文中提出一种能够实现可控制方向图零陷宽度和零陷数量的处理方法。该方法采用对阵列方向图响应矩阵的奇异值分解和重构,进行扩展的零空间基向量的求解。同时,针对提出的新方法的实际应用,论文给出了一种可实用的求解算法     

Hybrid Architecture and Beamforming Optimization for Millimeter Wave Systems

Hybrid beamforming(HBF) has become an attractive and important technology in massive multiple-input multiple-output(MIMO) millimeter-wave(mmWave) systems. There are different hybrid architectures in HBF depending on different connection strategies of the phase shifter network between antennas and radio frequency chains. This paper investigates HBF optimization with different hybrid architectures in broadband point-to-point mmWave MIMO systems. The joint hybrid architecture and beamforming optimi...     

层叠分布式天线系统混合分集技术

研究了层叠分布式天线系统(CascadeDistributedAntennaSystem,CDAS)空间两层分集的中断概率性能。层叠分布式天线系统包括间隔较远的N个天线簇,每个天线簇包括距离较近的L个天线单元。文中推导了层叠分布式天线系统中断概率的表达式。相比于传统的单天线系统,数值仿真表明采用混合分集的分布式天线系统可以有效抑制快衰落和阴影衰落。     

Large Antenna Array with Hybrid Beamforming System for 5G Outdoor Mobile Broadband Communication Deployments

Millimeter wave (mmWave) communication requires large antenna arrays to increase the capability of cellular networks of the fifth generation with good beam-forming gains and a substantial reduction in path losses for both transmitting and receiving terminals. As large antenna arrays require one radio frequency chain per antenna element, the fully digital beamforming technique results in high cost and high-power consumption, and it is therefore not feasible. However, in analog solutions, adaptive gain control cannot be used as it reduces the likelihood of advanced processing and contributes to poor efficiency. Hybrid schemes are possible exciting solutions that overcome the deficiencies of pure digital or analog beam forming. The following are the three key contributions of the proposed work: a typical link budget specification for target data rate 3.10 Gbps in downlink and 0.6 Gbps in uplink is provided, micro strip patch antenna with a single element is designed to operate at 28 GHz and then converted into a standard linear array and a Kalman-based hybrid analog/digital precoding is used with a downlink rate of 4.64 Gbps/cell and an uplink rate of 1.84 Gbps/cell in multi-user environments. And the influence of both base station (BS) and 5G User equipment (UEs) beam steering capability is also explored. From the simulation result, it is evident that the proposed work offers a substantial increase in spectral efficiency approximately 9.28 bps/Hz at 20 dB with 10 channel paths.

     

Hybrid Digital-Analog Coding with Bandwidth Compression for Gaussian Source-Channel Pairs

Three hybrid digital-analog (HDA) systems, denoted by HDA-I, HDA* and HDA-II, for the coding of a memoryless discrete-time Gaussian source over a discrete-time additive memoryless Gaussian channel under bandwidth compression are studied. The systems employ simple linear coding in their analog component and superimpose their analog and digital signals before channel transmission. Information-theoretic upper bounds on the asymptotically optimal mean squared error distortion of the systems are obtained under both matched and mismatched channel conditions. Allocation schemes for distributing the channel input power between the analog and the digital signals are also examined. It is shown that systems HDA* and HDA-II can asymptotically achieve the optimal Shannon-limit performance under matched channel conditions. Low-complexity and low-delay versions of systems HDA-I and HDA-II are next designed and implemented without the use of error correcting codes. The parameters of these HDA systems, which employ vector quantization in conjunction with binary phase-shift keying modulation in their digital part, are optimized via an iterative algorithm similar to the design algorithm for channel-optimized vector quantizers. Both systems have low complexity and low delay, and guarantee graceful performance improvements for high CSNRs. For memoryless Gaussian sources the designed HDA-II system is shown to be superior to the HDA-I designed system. When applied to a Gauss-Markov source under Karhunen-Loeve processing, the HDA-I system is shown to provide considerably better performance.     

Beam Tracking Particle Filter for Hybrid Beamforming and Precoding Systems

Because millimeter wave (mmWave) systems can span notably wide spectral bands, mmWave systems are expected to dominate fifth-generation (5G) communication systems. Due to the short wave-length of mmWave radiation, multiple-input multiple-output (MIMO) systems can use massive antennas and precoding technology to overcome signal attenuation in mmWave channels. However, the cost and power consumption of radio frequency (RF) chains would increase substantially with the number of antennas. Hence, hybrid beamforming was proposed to reduce the number of RF chains in massive MIMO systems. Hybrid beamforming involves RF beamforming matrix construction and baseband precoding matrix derivation. This study focused on the design and implementation of an algorithm for the RF beamforming matrix construction for mobile environments. Accordingly, this study presents a mixture particle filter that exploits the temporal continuity of beam clusters in a mobile mmWave channel to reduce the computational complexity of RF beamforming matrix construction. Moreover, this beam-tracking particle filter is based on parallel processing architecture to support the tracking of multiple beam clusters in the mmWave channel. Finally, the beam-tracking particle filter was implemented on a field-programmable gate array platform and was verified in a hybrid beamforming system for mmWave MIMO systems. The particle filter processor achieved a maximal throughput of 9.198k matrices/s with a clock rate of 192 MHz, which could support a speed of up to 88.5 km/h for mobile users.

     

Synthesizing Energy-Efficient Embedded Systems with LOPOCOS

In this paper, we introduce the LOPOCOS (Low Power Co-synthesis) system, a prototype CAD tool for system level co-design. LOPOCOS targets the design of energy-efficient embedded systems implemented as heterogeneous distributed architectures. In particular, it is designed to solve the specific problems involved in architectures that include dynamic voltage scalable (DVS) processors. The aim of this paper is to demonstrate how LOPOCOS can support the system designer in identifying energy-efficient hardware/software implementations for the desired embedded systems. Hence, highlighting the necessary optimization steps during design space exploration for DVS enable architectures. The optimization steps carried out in LOPOCOS involve component allocation and task/communication mapping as well as scheduling and dynamic voltage scaling. LOPOCOS has the following key features, which contribute to this energy efficiency. During the voltage scaling valuable power profile information of task execution is taken into account, hence, the accuracy of the energy estimation is improved. A combined optimization for scheduling and communication mapping based on genetic algorithm, optimizes simultaneously execution order and communication mapping towards the utilization of the DVS processors and timing behaviour. Furthermore, a separation of task and communication mapping allows a more effective implementation of both task and communication mapping optimizationsteps. Extensive experiments are conducted to demonstrate the efficiency of LOPOCOS. We report up to 38% higher energy reductions compared to previous co-synthesis techniques for DVS systems. The investigations include a real-life example of an optical flow detection algorithm.     

Hybrid Beamforming in Large-scale Antenna Array for 5G Indoor Communication Network Deployments

Wireless Personal Communications - The millimeter-wave multiple input multiple output (MIMO) technology is the frontier for 5G communication systems. This work contributes a large antenna array...     

数字波束赋形天线在个人通信系统中的应用

文章介绍了一项近十年来发展起来的新技术－数字波束形成技术的基本原理,并探讨了将数字波束形成天线用于个人通信在改善通信质量方面的作用和意义。     

天线阵列的波束赋形仿真

仿真了基于均匀线阵和圆阵的波束赋形技术,波束赋形使用线性约束最小方差准则,仿真结果表明,波束赋形能使天线主波束对准期望用户,低增益旁瓣或零陷对准干扰信号,达到有效利用有用信号抑制干扰信号的目的。     

基于辛算法的二维电磁场散射问题的研究

辛算法是保持Hamilton系统辛结构的一种新的数值方法,由于 Maxwell方程是一无穷维Hamilton系统,因此可将辛算法用于电磁场模拟中.本文提出一种基于辛分块Runge-Kutta(PRK)方法的显式辛算法,并将它成功应用于二维电磁散射问题的计算中.通过对金属方柱散射场的数值模拟,比较了FDTD法和低阶辛算法(一阶和二阶),结果表明低阶辛算法不仅与FDTD法精度相当,而且可以减少存储空间和计算时间,尤其是一阶辛算法节省了大约的CPU时间,提高了计算速度,体现了该算法的优越性.     

Energy-Efficient Resource Allocation in Mobile Networks with Distributed Antenna Transmission

This paper address the energy conservation issues in wireless downlink of mobile networks with distributed antenna transmission. From the basic information theory for MIMO channels, we derived a simple energy efficiency defined as number of bits per Watt. we then identified three approaches to improve the optimal energy efficiency with a higher capacity, which include alleviating channel fading loss, mitigating the interference, and increasing the number of antennas. We considered the scenario of a single cell with distributed antennas to jointly investigate above three factors. We first proposed a beamforming based energy-efficient resource allocation algorithm, which can achieve the optimal energy efficiency with a higher capacity through adaptively allocating resources and managing interferences. Due to the computational complexity of this algorithm and real-time processing requirement, we further proposed a low-complexity antenna-selection based resource allocation algorithm, which is more tractable and only with slightly performance loss. Finally, we compared different network configurations with these algorithms by extensive simulations, the results demonstrate that the proposed algorithms in distributed antenna configurations achieve better energy efficiency at a high operational throughput point.     

智能天线中新的波束形成方法

提出了智能天线中三种利用估计得到的信号导向向量直接形成波束的新方法.根据CDMA信号模型和多径信道模型,用码滤波法估计得到用户最强信号(主径)的导向向量,利用这些导向向量形成恢复期望信号,抑制干扰的制约条件.根据制约条件可直接得到最小二乘(LS)波束形成方法;按照制约条件使输出能量最小得到广义最小方差无失真响应(GMVDR)波束形成方法;在GMVDR方法的基础上引入虚拟信号来进一步抑制旁瓣得到扩展最小方差无失真响应(EMVDR)波束形成方法.模拟表明这三种方法都能很好的恢复期望信号、抑制干扰和噪声,但通过比较看出EMVDR方法形成的波束最好.     

The Development of Intelligent Beamforming Antenna Systems for Stratospheric Platforms in the Millimeter-Wave Band

In this paper, we describe intelligent beamforming antenna systems that can be used in the millimeter-wave band for High-altitude platform systems. We have developed two antenna systems for the millimeter-wave band and have designed experiments to test the efficiency of the developed systems. One is a multi-beam-horn antenna that enables high-speed transmission, and the other is an array antenna that digitally controls antenna beams. These antenna systems are also designed to work in the stratosphere. We also describe our solutions to the problems of low temperature and low pressure and show that the two antenna systems can function well in the stratosphere through tests conducted on the ground.On April 1, 2004, the Communications Research Laboratory (CRL) and the Telecommunications Advancement Organization of Japan (TAO) merged to create NICT.Hiroyuki Tsuji received the B.S., M.S., and Ph.D. degrees from Keio University in 1987, 1989, and 1992, respectively. Since 1992, he has been working in the Communications Research Laboratory, Independent Administrative Institution, Japan. In 1999, he was a visiting researcher at University of Minnesota. He is now a senior researcher of Wireless Innovation Systems Group in the Yokosuka Radio Communications Research Center of NICT (National Institute on Information and Communications Technology, reorganized from CRL in April 2004). His research interests are in array signal processing, particularly as applied to communications. He received the IEICE 1996 Young Engineer Award. He is a member of IEICE and IEEE.Masayuki Oodo was born in Osaka, Japan, on February 1, 1969. He received B.E., M.E. and D.E. degrees in Electrical and Electronic Engineering from Tokyo Institute of Technology, Tokyo, Japan in 1992, 1994 and 1997, respectively. In 1997, he joined the Communications Research Laboratory (CRL, now part of the National Institute of Information and Communications Technology, or NICT), where he has been researching array antennas for wireless communication and frequency-sharing issues between HAPS and other systems. Dr. Oodo received the Paper Presentation Award from IEICE Japan in 1995, the Young Scientist Award from URSI in 1996, the Young Engineer Award from IEICE Japan in 1997, and the Young Engineer Award from IEEE AP-S, Tokyo Chapter in 1998. He is a member of IEEE.Ryu Miura received the B.E., M.E., and PhD degrees in Electrical Engineering from Yokohama National University, Yokohama, Japan, in 1982, 1984, and 2000, respectively. He joined Communications Research Lab (CRL), Ministry of Posts and Telecommunications, Tokyo, Japan in 1984, where he worked for research on mobile satellite communication systems using the Engineering Test Satellite, ETS-V. During 1991–1992, he was a visiting researcher in AUSSAT, Pty. Ltd. (now Optus, Pty. Ltd.), Sydney, Australia. During 1993–1996, he was a senior researcher in ATR Optical and Radio Communications Research Labs, Kyoto, Japan, where he worked for research on digital beamforming antennas for mobile communications. He is now a group leader of Wireless Innovation Systems Group in the Yokosuka Radio Communications Research Center of NICT (National Institute on Information and Communications Technology, reorganized from CRL in April 2004), where he works for R&D on wireless communication systems using stratospheric platforms. Dr. Miura is a member of IEEE and IEICE.Mikio Suzuki received a B.S. degree in electronic engineering from Keio University in 1970. He joined Mitsubishi Electric Corporation in 1970, where he researched and developed microwave integrated circuits and waveguide array antennas for defense radars and missiles. He is now at the NICT Yokosuka Stratospheric Platform Research Center, and his current research interests lie in the system design of applications for wireless communication systems using a stratospheric platform and the development of related communication equipment. He is a member of the IEICE of Japan.     

Hybrid Beamforming for Massive MIMO Using Rectangular Antenna Array Model in 5G Wireless Networks

Fifth and future generation (5G and B5G) wireless networks aim to serve users with higher data rates and lower latency. Data traffic due to the rapid growth in communication has motivated the study of Multiple Input Multiple Output (MIMO) systems. They utilize multiple antennas in both transmitter and receiver sides. It is necessary to improve the existing technology to achieve fast and reliable communication. In this research work, a rectangular array antenna based hybrid beamforming in a massive MIMO model has been proposed to improve the spectral efficiency of the system. Thus channel capacity with small RF chains is used. To achieve the high signal strength in the main lobe, Chebyshev tapering has been used to suppress the side lobes signals. In this manner, the proposed Hybrid Beamforming for Massive Output MIMO has been realized with a small complexity and higher spectral efficiency. In this research work, the spectral efficiency of both proposed Hybrid and fully-digital beamforming with a different number of RF chains for a various number of antennas at the transmitter, the receiver side has been analyzed. From the simulation results, it has been observed that the proposed rectangular array antenna based Hybrid beamforming in a massive MIMO system reduces the computational complexity up to 99% as compared with conventional fully digital beamforming to achieve the same spectral efficiencies, which is a productive model for 5G wireless networks.