Multipoint System Research Articles

Distributed Energy-Efficient Power Optimization for CoMP Systems With Max-Min Fairness

This letter considers the power optimization problem for downlink transmission in coordinated multi-point (CoMP) systems. We aim to maximize the minimum weighted energy efficiency (EE) with QoS constraint and limited intercell coordination. The established optimization problem is converted to the standard form of max-min fractional programming problem first. Then we discuss feasibility of the Dual Dinkelbach-type Algorithm (DDA). A distributed algorithm is proposed to solve the subproblem in DDA with limited intercell coordination, where only a small number of positive scalars are shared between base stations. Simulation results show that the proposed algorithm outperforms previous schemes in terms of both the minimum EE of all the BSs' EE and fairness.

Study on Optimization of Signal Transmission Technology Based on Layered Source with Superposition Coding

The optimization of wireless multipoint multimedia broadcasting system layered source transmission was studied and analyzed. The introduction of continuous layered source with superposition coding model infinite layer in this article, the optimal inter-layer power distribution function is given by variation method, then an average per user up to speed is obtained. In the simulation, the LSSC which introduces a layered source coding scheme compared with the traditional CB Scheme. LSSC transmit multiple data streams to meet different end user channel conditions is verified by the results. The problem of system performance loss due to channel asymmetry between the center of the cell edge users and users bring have been effective solved.

A Monitoring and Fault Diagnosis System for Aero-Engine Pipeline Based on Distributed Fiber Bragg Grating Sensor

Aero-engine pipeline is the cardiovascular of aero-engine, which directly affects the safety and reliability of planes. However, the pipeline has complex structure and is easily broken by the harsh operation environment. Therefore, the condition monitoring and fault diagnosis of aero-engine pipeline play one of the most important role to ensure the aero-engine safe and reliable. Fiber Bragg Grating Sensor (FBGS) owns several characteristics, such as anti-electromagnetic interference, corrosion resistance, small size, performance stability, long lifecycle, as well as easy to constitute distributed multi-point system. In this paper, a condition monitoring and fault diagnosis system for aero-engine pipeline, including online monitoring and offline diagnosis, is proposed. Moreover, online monitoring based on temperature and strain signals and offline fault diagnosis based on simulated vibration signals of aero-engine pipeline are explained in details. According to the experimental results, the proposed system is useful and effective.

Clustering and scheduling methods based on SLNR in downlink CoMP system

In downlink coordinated multi-point (CoMP) system, full cooperation is always not applicable in real world because of its high request in the backhaul. To deal with this problem, clustering decision is made to process transmission. In this paper clustering methods based on the metric signal-to-leakage-plus-noise (SLNR) is proposed. In addition, user scheduling schemes based on SLNR is also put up to make the scheduling set as large as possible. Simulation results show that the proposed clustering methods not only reduce the data sharing among the cooperating base stations (BSs), but also improve the system throughput compared with the traditional clustering methods based on channel strength.

Multipoint video control and fall detection system applicable in assistance of the elderly and people with disabilities

The population of elderly people keeps increasing rapidly, which becomes a predominant aspect of our societies. Ambient assisted living (AAL) is new research area which promises to address the needs of the elderly and people with disabilities. AAL has a lot of barriers and challenges that impede its development and more universal deployment. These could be summarised as: technological, ethical, legal and psychological challenges. An approach allowing overcoming part of these barriers, mostly related to the integration of a video control system in the assistive process, is presented by the authors in this paper.

A Low-Complexity Cross-Layer Algorithm for Coordinated Downlink Scheduling and Robust Beamforming Under a Limited Feedback Constraint

Coordinated scheduling/beamforming (CS/CB) substantially mitigates the intercell interference (ICI), hence increasing the cell-edge throughput on the downlink (DL) of coordinated multipoint (CoMP) systems. To maximize the DL throughput, the cooperating base stations (BSs) jointly select the best set of users for DL scheduling and then jointly design a set of beamforming (BF) vectors to approach the throughput limit. However, finding the optimal BF vectors requires an exhaustive search and substantial channel state information (CSI) feedback, hence resulting in high algorithmic complexity and heavy uplink traffic load. Hence, we conceive a new cross-layer algorithm to achieve high performance at a lower feedback amount and at lower algorithmic complexity. Based on the fact that different BSs usually have different traffic loads, we divide the BSs into two different types, i.e., the master BSs (MBSs) and the slave BSs (SBSs), where MBSs have a higher transmission priority than SBSs. The scheduling relies on an interference threshold, whereas our robust BF scheme exploits both the channel direction information (CDI), which is quantized using the technique of limited feedback, and the channel quality information (CQI), which is assumed to be fed back accurately. Our numerical results show that the proposed algorithm does not lose much performance compared with that achieved by an exhaustive search, whereas the algorithmic complexity is as low as that of the solutions operating without CoMP.

Non-stationary corona around multi-point system in atmospheric electric field: II. Altitude and time variation of electric field

The vertical electric field profile during thunderstorms was studied numerically and analytically above the plane ground surface with irregularities that generated ions when the surface electric field was sufficient for ion emission. The computer model of a plane emitting ions into the atmosphere simulated a limiting case of a non-stationary glow corona occurring near the tips of a multi-point ground system in a time-varying thundercloud electric field. The evolution of electric field profiles for various rates of change of thundercloud electric field was analyzed and the peculiarities of electric field measurements during thunderstorms were considered. A computer model was developed to estimate the temporal evolution of electric field above a multi-point coronating system. Conditions under which the electric field evolution above a multi-electrode system is similar to that above a plane emitting surface were determined. The evolution of the surface electric field below coronating points in a multi-electrode system was calculated. Conditions when the surface electric field tends to the thundercloud electric field necessary for corona onset in a multi-point system were obtained.

Applications of Multi-Point Mirror Supporting

Primary mirror (PM) supporting system design is one of the key components to the design of a telescope. This paper presents applications of extended multi-point supporting structures that are employed in ground based theodolites, 3 points positioning-9 points supporting system and 18 points supporting system. A number of theoretical studies have been performed using Finite Element Analysis (FEA) on each supporting system, in which the extended multi-point supporting system to 0.6-m and 1-m diameter primary mirror is particularly focused. Analyzing Zerodur major mirrors with a diameter to thickness ratio less than 7.3, deformation due to supporting gives an RMS value less than 6-nm which is 24% of the design requirement of 60-nm. Series of experiments have also been conducted using 4-D interferometer. The deformation due to supporting of major mirror has been predominantly suppressed mainly by deformation during the fabrication process. This indicates that the above supporting systems perform an excellent task under given conditions.

The Research of Fixation Method in Tea Processing Based on Fuzzy Control

Aiming at the nonlinear and coupling phenomena of temperature and humidity changes appearing in the course of tea fixation, this paper introduces the fuzzy control technology in the process of making tea. STM32F107 microcontroller is as the core of the whole system and the multi-point detection system is used in real-time collection of two parameters of temperature and humidity . In addition, data transmission is realized between PC and I2C, SPI bus. The control rules and parameters of controller are formulated and the temperature and humidity of tea fixation multi-parameter control are realized. Fuzzy decoupling control is adopted to meet the process requirement of temperature and humidity change in process. It improves the precision of temperature and humidity control and the quality of tea.

Coordinated Multi-Point Transmission Strategies for TDD Systems with Non-Ideal Channel Reciprocity

This paper studies transmission strategies for downlink time division duplex coordinated multi-point (CoMP) systems with non-ideal uplink-downlink channel reciprocity, where several multi-antenna base stations (BSs) jointly serve multiple single-antenna users. Due to the inherent antenna calibration errors among different BSs, the uplink-downlink channels are no longer reciprocal such that the channel information at the BSs is with multiplicative noises. To mitigate the performance degradation caused by the imperfect channels, we employ a weighted sum rate estimate as the objective function for robust precoder design. To show the impact of data sharing on the performance of CoMP under the non-ideal channel reciprocity, we provide a unified framework for designing precoder for CoMP systems with different amount of data sharing. The optimal parametric linear precoder structure that maximizes the weighted sum rate estimate under per-BS power constraints is characterized, based on which a closed-form robust signal-to-leakage-plus-noise ratio (SLNR) precoder is proposed to exploit the statistics of the calibration errors. Simulation results show that the proposed precoder in conjunction with user scheduling provides substantial performance gain over Non-CoMP transmission and the CoMP transmission with non-robust precoders.

Experimental study to identify common engine part load conditions between Malaysian city driving and NEDC test

This paper describes an experimental study conducted to identify the common engine part load conditions between Malaysian city driving and NEDC (New European Driving Cycle) test on a 4 cylinder gasoline fuelled engine, with multi-point fuel injection system, and continuous variable transmission vehicle. This is to pinpoint a regional area from the part load map in the attempt to strategize key technologies such as CDA (Cylinder Deactivation) or CNG (Compressed Natural Gas). Technologies such as CDA or CNG do not operate at all engine operations. Due to certain drawbacks, the operation of the technologies must be strategized to obtain most benefit from the engine. With the knowledge of the common part load region, these technologies could be integrated and strategized into the region to reduce overall fuel consumption. With improvements in fuel consumption respective to the identified common part load operations, the overall fuel consumption benefit does not only serve the legislation but also most importantly benefit the local consumers who travel on Malaysian roads.

A Multi-Cell Coordinated Scheduling Algorithm Based on Delta-CQI for CoMP Network Systems

In the coordinated scheduling/beamforming of coordinated multi-point (CoMP) systems, a multi-cell coordinated scheduling algorithm is proposed for inter-cell interference coordination and cell-edge users’ throughput enhancement. The concept of Delta-CQI is introduced to indicate the interference level experienced by users in one cell when the users in adjacent cells of the cooperation region using different precoding vectors. Adjacent base stations exchange the information of Delta-CQI which is fed back from the users in each cell and calculate the weighted interference factor, then the user scheduling is performed by the multiple cells in the cooperative cell set along with the priority factor given by the proportional fairness scheduling algorithm used in each cell. The proposed multi-cell coordinated scheduling algorithm considers the user interference among different cells to improve the data rate of users in cell edge, which gives a good tradeoff between system fairness and spectrum efficiency. Beside that, the overhead of the control information exchange among coordinated cells are reduced by the Delta-CQI feedback and exchange.

The Design and Realization of Intelligent Control System in Temperature and Humidity of Tea Intelligent Fixation

Aiming at the difficulty in control in tea fixation process, the intelligent control technology is adopted in the research which is for the core to the C8051F340 SCM and adopts the multi-point detection system to collect the temperature and humidity data. Besides, the data transmission with the epistemic machine can be realized by the I2C Bus, SPI and so on while the control rules and parameters of the controller can be intended. Thus it can be seen that the multi-parameter control of the temperature and humidity can be realized in tea green removing technology. The bunk watchdog circuit is adopted in hardware design to repair the systems bug automatically and safeguard the control system operate stably for a long time in this research. Additionally, the PID control algorithm is applied in software design to control systemic error less than 2%. Practical application indicates that this system is with simple structure, high reliability and good scalability, and it also can reduce the amount of labor and improve the teas quality.

Network Monitoring System of Multipoint Temperature Collection and Control

The temperature monitoring control is the most basic data parameters of the daily life and industrial production; it also has very important significance in multi-point temperature collection, accurate measurement and control monitoring. Therefore, this paper was based on SCM to deal with the temperature information data, design the multipoint temperature monitoring system, design the function of multipoint temperature collection and control network monitor system and main program, subroutine and so on. At the same time, this paper expounded the design methods of temperature acquisition, calculation and display. It used the thermistor temperature sensor to measure real-time temperature of the periphery environment, and voltage change that transformed from the measured temperature was transmitted to ADE0708 converter for modulus conversion, and the number was input to the serial interface and dealt with computer software to output conversion by SCM, digital tube was displayed in digital sections, it was the real-time temperature value. According to the converter channel port it could set output driving control signal, the display light had status indication and adjustment and control.

Wireless and Multi point system based on Image Processing

최근 산업의 발전과 더불어 기존의 컴퓨터 기술은 단순히 OA기능을 넘어서 사회 전반의 다양한 영역에서 사용되고 있다. 하지만 기존의 레이저포인터를 활용한 무선 입력 시스템에서는 한 개의 레이저 포인터에 대하여 기본적인 마우스 기능만을 제공한다. 카메라에 광학 밴드패스를 이용하여 포인팅을 하는 시스템은 광학필터가 고가여서 상용화가 어려웠으며, 최근 컴퓨터 성능의 발달로 이러한 광학 밴드패스 필터는 소프트웨어만으로 충분히 구현 가능해졌다. 본 논문에서는 이러한 기존의 연구를 개선하고 활용도를 높이기 위하여 두 개의 레이저 포인터를 이용하여 멀티 포인트 입력을 지원할 수 있는 방법에 대한 연구를 진행하였다. 그 결과, 스크롤, 확대/축소 등 터치패드와 동일한 멀티터치 기능을 수행할 수 있게 되어 사용자의 인터랙티브한 무선입력이 가능하게 되었다.

An Approach in Full Duplex Digital Multipoint Systems Using Large Signal Power Line Communication

The main aim of this paper is to introduce a robust method for distance enhancing of a narrow band digital multipoint communication system. Despite the conventional power line carrier technologies and communicating standards such as EIA – 485, the large signal definition of the Frequency and Amplitude combined Modulations in Power Line Communication (FAMPLC) eliminates the requirement of any repeater facility for the distant access. In this paper, the Frequency Modulated Power Supply (FMPS) in one end and active resistances as dummy loads at the other ends to establish full – duplex large signal power line communication in independent voltage and current layers are presented. The design methodology, data extraction methods and error compensation techniques that resulted in a successful development are discussed. The article presents some promising patents on full duplex digital multipoint systems using large signal power line communication. Keywords: Dummy active resistance, FAMPLC, FMPS, Large signal power line communication.

Design of Multi-Channel Temperature and Humidity Sensor Acquiring System

In this paper, the design of remote multi-point temperature and humidity control system consists of two parts of the master and slave, Responsible for the display and control of the host system. Responsible for the collection of temperature data and humidity data from the local system, Between the master and slave data transmission RS-485 communication interface chip, can be realized in a remote control room to monitor the scene of multiple monitoring points.

Non-stationary corona around multi-point system in atmospheric electric field: I. Onset electric field and discharge current

The properties of a non-stationary glow corona maintained near the tips of a multi-point ground system in a time-varying thundercloud electric field have been studied numerically and analytically. Computer and analytical models were developed to simulate the corona discharge initiated from a system of identical vertical conductive electrodes distributed uniformly over a grounded plane surface. The simulation was based on a solution of the electrostatic equation for electric field and continuity equations for light and aerosol ions. The development of individual corona space charge layers from different points and the formation of a united plane layer were considered. The effect of system dimensions and that of the distance between electrodes on the external electric field corresponding to corona onset near the rod tips was investigated. The evolution in time of the corona current was calculated for systems with various numbers of coronating rods in time-varying atmospheric electric field. In the limit of infinite number of coronating rods, reasonable agreement was obtained between numerical calculations and analytical theory considering the effect of surrounding rods on the corona discharge from a given rod in a simplified integral way. Conditions were determined under which the corona properties of a multi-point system are similar to the properties of a plane surface emitting ions into the atmosphere. In this case, the corona current density is governed by the time derivative of the thundercloud electric field and is independent of the ion mobility and of the coronating system dimensions. The total corona space charge injected into the atmosphere per unit area by a given instant is controlled by the thundercloud electric field at this instant and depends on the geometrical parameters of the system only indirectly, through the corona onset atmospheric electric field. This simple model could be used to simulate a corona discharge during thunderstorms at the earth’s surface covered with dense vegetation. In particular, according to the model of an emitting plane, the current densities in the range 1–10nA/m2 are expected when the thundercloud electric field increases by ∼50kV/m over time interval in the range 30–300s, in qualitative agreement with the analysis of available field observations.

Analysis of coordinated transmission pre-coding in distributed wireless communication system

In distributed wireless communication and Coordinated Multi-Point(CoMP) system,the deterioration of channel quality seriously affect the system receptivity of edge users,and therefore the coordinated coding processing is used to improve the quality of reception.A coordinated transmission and joint pre-coding method was proposed in this paper.Coordinated Remote Antenna Units(RAU) were processed jointly.According to the state information of channel,different pre-coding rules were adopted by each RAU to transmit data to the same user.A Maximal-Ratio Combining(MRC) algorithm was used to calculate the received signals of terminals.The simulation results show that the proposed method can effectively decrease the Bit Error Rate(BER) and improve the transmission reliability.

Experiment Study of the Single Point and Multi-Point Natural Gas Electronic Injection Systems

To compare and improvediesel engine emission performance by different injection methods, a multi-pointnatural gas in-system and a one-point injection system were developed. In bothsystems, the electromagnetic valves are used to control injection and totalquantity. The system was designed for the type X6130 diesel engine. The testresults showed that the multi-point system has great advantages in the aspectsof emissions. To adopt multi-point gas injection is a better way to reduce theemission.