Showing papers on "Data transmission published in 2009"

High data rate multiple input multiple output (MIMO) optical wireless communications using white led lighting

Abstract: Solid-state lighting is a rapidly growing area of research and applications, due to the reliability and predicted high efficiency of these devices. The white LED sources that are typically used for general illumination can also be used for data transmission, and Visible Light Communications (VLC) is a rapidly growing area of research. One of the key challenges is the limited modulation bandwidth of sources, typically several MHz. However, as a room or coverage space would typically be illuminated by an array of LEDs there is the potential for parallel data transmission, and using optical MIMO techniques is potentially attractive for achieving high data rates. In this paper we investigate non-imaging and imaging MIMO approaches: a non-imaging optical MIMO system does not perform properly at all receiver positions due to symmetry, but an imaging based system can operate under all foreseeable circumstances. Simulations show such systems can operate at several hundred Mbit/s, and up to Gbit/s in many circumstances.

Multi-media broadcast and multicast service (MBMS) in a wireless communication system

Abstract: Techniques to implement MBMS services in a wireless communication system. In one aspect, a method is provided for processing data for transmission to a plurality of terminals. Frames of information bits (which may have variable rates) are provided to a buffer implementing a matrix. The matrix is padded with padding bits based on a particular padding scheme to support variable frame rates. The frames are then coded based on a particular block code to provide parity bits. The frame of information bits and the parity bits are then transmitted to the terminals. In another aspect, a method is provided for controlling the transmit power of a data transmission to a plurality of terminals. In accordance with the method, TPC streams are received from the terminals and processed to obtain a stream of joint power control commands used to adjust the transmit power of the data transmission.

Statistical Characterization of 60-GHz Indoor Radio Channels

Abstract: An extensive review of the statistical characterization of 60-GHz indoor radio channels is provided from a large number of published measurement and modeling results. First, the most prominent driver applications for 60 GHz are considered in order to identify those environment types that need to be characterized most urgently. Large-scale fading is addressed yielding path-loss parameter values for a generic 60-GHz indoor channel model as well as for the office environment in particular. In addition, the small-scale channel behavior is reviewed including the modeling of time-of-arrival and angle-of-arrival details and statistical parameters related to delay spread, angular spread and Doppler spread. Finally, some research directions for future channel characterization are given.

Method and system for integrated wireless power and data communication

Abstract: A method and system of integrated wireless power and data transmission in a wireless device having a data communication circuit for wireless data communication and a power reception circuit including a charge storage unit. The wireless device is tuned to receive wireless RF signals in a certain frequency band via an antenna. Switching between power reception mode and data communication mode is detected. Received RF signal electrical charge is selectively distributed to the power reception circuit and/or the data communication circuit based on the switching mode and/or strength of the RF signal.

Data Rate Theorem for Stabilization Over Time-Varying Feedback Channels

Abstract: A data rate theorem for stabilization of a linear, discrete-time, dynamical system with arbitrarily large disturbances, over a rate-limited, time-varying communication channel is presented. Necessary and sufficient conditions for stabilization are derived, their implications and relationships with related results in the literature are discussed. The proof techniques rely on both information-theoretic and control-theoretic tools.

A calculus approach to energy-efficient data transmission with quality-of-service constraints

Abstract: Transmission rate adaptation in wireless devices provides a unique opportunity to trade off data service rate with energy consumption. In this paper, we study optimal rate control to minimize transmission energy expenditure subject to strict deadline or other quality-of-service (QoS) constraints. Specifically, the system consists of a wireless transmitter with controllable transmission rate and with strict QoS constraints on data transmission. The goal is to obtain a rate-control policy that minimizes the total transmission energy expenditure while ensuring that the QoS constraints are met. Using a novel formulation based on cumulative curves methodology, we obtain the optimal transmission policy and show that it has a simple and appealing graphical visualization. Utilizing the optimal ldquoofflinerdquo results, we then develop an online transmission policy for an arbitrary stream of packet arrivals and deadline constraints, and show, via simulations, that it is significantly more energy-efficient than a simple head-of-line drain policy. Finally, we generalize the optimal policy results to the case of time-varying power-rate functions.

Data Transmission Over Networks for Estimation and Control

Abstract: We consider the problem of controlling a linear time invariant process when the controller is located at a location remote from where the sensor measurements are being generated. The communication from the sensor to the controller is supported by a communication network with arbitrary topology composed of analog erasure channels. Using a separation principle, we prove that the optimal linear-quadratic-Gaussian (LQG) controller consists of an LQ optimal regulator along with an estimator that estimates the state of the process across the communication network. We then determine the optimal information processing strategy that should be followed by each node in the network so that the estimator is able to compute the best possible estimate in the minimum mean squared error sense. The algorithm is optimal for any packet-dropping process and at every time step, even though it is recursive and hence requires a constant amount of memory, processing and transmission at every node in the network per time step. For the case when the packet drop processes are memoryless and independent across links, we analyze the stability properties and the performance of the closed loop system. The algorithm is an attempt to escape the viewpoint of treating a network of communication links as a single end-to-end link with the probability of successful transmission determined by some measure of the reliability of the network.

System and method for preventing data loss using virtual machine wrapped applications

Abstract: A method in one example implementation includes selecting at least one criterion for controlling data transmission from within a virtual machine. At least one application is included within the virtual machine, which includes a policy module. The selected criterion corresponds to at least one policy associated with the policy module. The method also includes evaluating the selected criterion of the policy to permit an attempt to transmit the data from within the virtual machine. In more specific embodiments, the policy may include a plurality of criteria with a first selected criterion permitting transmission of the data to a first application and a second selected criterion prohibiting transmission of the data to a second application. In another specific embodiment, the method may include updating the policy module through an administration module to modify the selected criterion.

Dense wavelength multiplexing of 1550 nm QKD with strong classical channels in reconfigurable networking environments

Abstract: To move beyond dedicated links and networks, quantum communications signals must be integrated into networks carrying classical optical channels at power levels many orders of magnitude higher than the quantum signals themselves. We demonstrate the transmission of a 1550 nm quantum channel with up to two simultaneous 200 GHz spaced classical telecom channels, using reconfigurable optical add drop multiplexer (ROADM) technology for multiplexing and routing quantum and classical signals. The quantum channel is used to perform quantum key distribution (QKD) in the presence of noise generated as a by-product of the co-propagation of classical channels. We demonstrate that the dominant noise mechanism can arise from either four-wave mixing or spontaneous Raman scattering, depending on the optical path characteristics as well as the classical channel parameters. We quantify these impairments and discuss mitigation strategies.

Channel Estimation for OFDM Modulated Two-Way Relay Networks

Abstract: In this work, we introduce the model of employing orthogonal-frequency-division multiplexing (OFDM) for transmission over time-dispersive channels in the two-way relay network (TWRN), where two source terminals exchange their information through a relay terminal using the amplify-and-forward (AF) relaying scheme. We propose a two-phase training protocol for the channel estimation, which is compatible with the two-phase data transmission scheme. In the first phase, the two source terminals send their individual training sequences concurrently to the relay, while in the second phase the relay amplifies the received training sequences and broadcasts them to both source terminals. We propose two different types of training methods as well as develop their corresponding channel estimation algorithms at each of the two source terminals. The first type of training is block based, for which we first estimate the cascaded source-relay-source channels, and then design algorithms to recover the individual channels between sources and relay. The second type of training is pilot-tone (PT) based, for which we propose to directly estimate the individual channels between sources and relay. Moreover, the identifiability issues on the nonambiguous estimate of the channels in both types of proposed training are carefully addressed. Finally, various numerical examples are presented to corroborate our analytical results.

Propagation Issues for Cognitive Radio

Abstract: Cognitive radios are expected to work in bands below about 3.5 GHz and may be used for a variety of applications, e.g., broadband fixed wireless access, mobile and nomadic access, etc. Cognitive radio system designers must have access to a wide range of channel models covering a wide span of operating frequencies, carrier bandwidths, deployment conditions, and environments. This paper provides a comprehensive overview of the propagation channel models that will be used for the design of cognitive radio systems. We start with classical models for signal loss versus distance and discuss their dependence on the physical properties of the environment and operating frequency. Here we also introduce the concept of log-normal shadowing resulting from signal blockage by man-made and natural features. Next, we discuss the time-varying nature of the wireless channel, introduced as a result of the motion of objects in the channel. This is followed by a discussion on the dispersion of the signal caused by various effects of propagation, especially in the time and frequency domains. Angular dispersion, which is discussed next, is important because cognitive radios may be based on modems that exploit the spatial domain. Lastly, we summarize channel models that have been standardized for fixed and mobile systems.

White rabbit: Sub-nanosecond timing distribution over ethernet

Abstract: White Rabbit (WR) is the project name for a ambiguous project that uses Ethernet as both, deterministic (synchronous) data transfer and timing network. The presented design aims for a general purpose, fieldbus like transmission system, which provides deterministic data and timing to approximately 1000 timing stations. The main advantage over conventional systems is the highly accurate timing (sub-nanosecond range) without restrictions on the traffic schedule and an upper bound for the delivery time of high priority messages. In addition, WR also automatically compensates for transmission delays in the fibre links, which are in the range of 10 km length. It takes advantage of the latest developments on synchronous Ethernet and IEEE 1588 to enable the distribution of accurate timing information to the nodes saving noticeable amounts of bandwidth.

Communication system and data transmission method thereof

Abstract: A communication system and data transmission method thereof are provided. The method includes adding an end marker to the end of source data and transmitting the source data and the end marker for a Packet data network GateWay (PGW) to a source evolved Node B (eNB) if a handover is carried out from the source eNB to a target eNB while the PGW is transmitting the source data to the source eNB, forwarding the source data and the end marker from the source eNB to the target eNB, transmitting target data immediately following the source data from the PGW to the target eNB, and transmitting the source data and the target data, which is classified into the source data by the end marker and immediately follows the end of the source data, from the target eNB to user equipment.

Convergence of ethernet PON and IEEE 802.16 broadband access networks and its QoS-aware dynamic bandwidth allocation scheme

Abstract: IEEE 802.16 and Ethernet Passive Optical Network (EPON) are two promising broadband access technologies for high-capacity wireless access networks and wired access networks, respectively. They each can be deployed to facilitate connection between the end users and the Internet but each of them suffers from some drawbacks if operating separately. To combine the bandwidth advantage of optical networks with the mobility feature of wireless communications, we propose a convergence of EPON and 802.16 networks in this paper. First, this paper starts with presenting the converged network architecture and especially the concept of virtual ONU-BS (VOB). Then, it identifies some unique research issues in this converged network. Second, the paper investigates a dynamic bandwidth allocation (DBA) scheme and its closely associated research issues. This DBA scheme takes into consideration the specific features of the converged network to enable a smooth data transmission across optical and wireless networks, and an end-to-end differentiated service to user traffics of diverse QoS (Quality of Service) requirements. This QoS-aware DBA scheme supports bandwidth fairness at the VOB level and class-of-service fairness at the 802.16 subscriber station level. The simulation results show that the proposed DBA scheme operates effectively and efficiently in terms of network throughput, average/maximum delay, resource utilization, service differentiation, etc.

Transmission method and devices in a communication system with contention-based data transmission

Abstract: A method is described for data transmission by user equipments adapted to transmit data using resource blocks allocated by a radio network. The radio network is adapted to allocate resource blocks to a dedicated one of the user equipments or to a plurality of the user equipments. The method comprises the step of allocating at least one of the resource blocks that is not allocated to any dedicated user equipment to a first plurality of the user equipments. The allocation is signaled to the user equipments. A first user equipment of said first plurality obtains data for transmission. At least a first part of the data is transmitted by the first user equipment using said at least one resource block. Devices embodying the invention and methods of operating the devices are also described. Contention based data transmission in uplink is enabled without previous scheduling request and scheduling grant.

System, device and method for data transfer to a vehicle and for charging said vehicle

Abstract: A data transfer, power supply and charging apparatus having a data interface transfers both energy to an energy storage device and vehicle- or driver-related data via a charging cable or electric line. The use of a charging cable for transmitting data to and from the vehicle is suitable particularly for electric and hybrid vehicles in the automotive sector. In this way, it is possible to perform updates for vehicle-internal systems and to check these. In addition, the data transfer, power supply and charging apparatus may include a communication unit which also allows data to be received and sent during travel without an electrical connection.

Sounding reference signal arrangement

Abstract: A method, apparatus, and computer program embodied on a computer-readable medium to create an uplink message to be transmitted to a base station, the created uplink message comprises a sounding reference signal based on accessed data. An uplink scheduling grant signal is received via downlink, from the base station, in response to the transmission of the uplink message. An uplink data transmission is transmitted to the base station responsive to the received uplink scheduling grant signal.

Communication system, node device, communication method in the communication system, and program

Abstract: A communication system comprises: failure detection means that detects a failure on a first transmission path over which data transmission is being performed; transmission path setting means that, when the failure exists in a link or a node that is located immediately before its own node, sets a second transmission path as far as a transmission terminal node, the second transmission path that excludes a path from the transmission terminal node to a node that has detected the failure within the first transmission path; first failure notification means that transmits a failure notification signal as far as the transmission terminal node over the second transmission path; new path switching means that, upon receipt of the failure notification signal, switches a switch for data transmission so that a path for new data transmission is the same path as a transmission path for the failure notification signal; and data transmission means that, upon the transmission terminal node receiving the failure notification signal, switches the switch to the second transmission path and performs a new data transmission over the second transmission path.

Low-Power, Intelligent Sensor Hardware Interface for Medical Data Preprocessing

Abstract: This work proposes an interface design of a low-power programmable system on chip for intelligent wireless sensor nodes to reduce the overall power consumption of the heart disease monitoring system, by lending them the capability of processing complex functions and performing rapid computations on a large amount of data at the node. This facilitates the node to intelligently monitor a medical signal for impending events instead of transmitting the signal to the base station constantly. Lowering the transmission data rate decreases the transmission power consumption in a node, thereby lengthening the node life and in turn increasing the reliability of the network. This work also implements a thresholding technique, which controls the data transmission rate depending on the value of the monitored signal, and a cardiac monitoring system that performs computations at the node for the detection of either a skipped heart beat or a reduced heart rate variability, in which event the signal is transmitted to the base station for monitoring/recording or alerting the crew. The performance analysis of the system shows that there are reductions in the system power consumption and data transmission rate, which in turn reduces the network traffic and averts congestion.

1.28 Tbit/s single-polarisation serial OOK optical data generation and demultiplexing

Abstract: A 128 Tbaud data signal is demonstrated, which is the highest symbol rate yet reported The data signal is formed by optical time-division multiplexing of 128 data channels at 10 Gbit/s OOK in a single polarisation The generated 128 Tbit/s data signal is demultiplexed in a nonlinear optical loop mirror, resulting in error-free performance with a BER<10−9 for all 128 demultiplexed channels

Wireless communication methods utilizing a single antenna with multiple channels and the devices thereof

Abstract: The present invention provides wireless communication methods utilizing a single antenna with multiple channels and the devices thereof. The method includes providing a plurality of communication channels within the single antenna. The plurality of communication channels may include a probe channel and a data channel. The single antenna may selectively switch between the probe channel and the data channel based on a probe signal transmitted in the probe channel so as to facilitate data transmission.

A 60 GHz Radio-Over-Fiber Network Architecture for Seamless Communication With High Mobility

Abstract: We demonstrate a 60 GHz broadband picocellular Radio-over-Fiber network architecture that enables seamless connectivity for highly mobile end-users. Its seamless communication capabilities arise by the supported handover scheme that relies on a novel Moving Extended Cell (MEC) concept. MEC exploits user-centric virtual groups of adjacent cells that transmit the same data content to the user and utilizes a switch mechanism for restructuring the virtual multi-cell area according to the user's mobility pattern, so that a virtual antenna group moves together with the mobile user. We present the theoretical formulation for MEC and show that it can provide zero packet loss and call dropping probability values in high-rate wireless services for a broad range of mobile speeds up to 40 m/sec, independently of the fiber link distances. We also demonstrate the physical layer network architecture and switch mechanism both for a RoF network with a single 60 GHz radio frequency (RF) over each wavelength, as well as for a RoF configuration supporting simultaneous multi-RF channel transmission over each optical wavelength. The performance of the multi-RF-over-lambda network implementation is evaluated via simulations showing successful 100 Mb/s radio signal transmission over fiber links longer than 30 km. To this end, MEC can enable seamless connectivity and bandwidth guarantees in 60 GHz picocellular RoF networks being also capable of serving multiple users over the same wavelength in a RF frequency-division-multiplexed (FDM) approach.

Capacity analysis for distributed antenna systems using cooperative transmission schemes in fading channels

Abstract: Wireless systems equipped with distributed antennas can provide enhanced data throughput as well as improved signal quality when appropriate cooperative transmission schemes among antennas are employed. In this paper, the performance of distributed antenna systems (DAS) under the influence of Rayleigh fading and log-normal shadowing effects is investigated for different cooperation strategies, and corresponding statistical distributions for both the signal-to-interference ratio (SIR) and the capacity are presented. Specifically, the ergodic capacity per remote antenna (RA) is determined when n RAs cooperatively transmit the desired signal to the target receiver, which is compared with the non-cooperative single-antenna transmission (SAT) case. Using the results, a preferable mode of operation for given geographic locations of the receiver is determined. We further propose to perform an adaptive operation between the cooperative and non-cooperative modes under the capacity maximization criteria, and quantify exact amounts of capacity gain over individual transmission modes.

Data Collection and Storage Device

Abstract: A data collection apparatus includes a network of sensing units for sensing a parameter. Each sensing unit of the network of sensing units includes a sensor, a first data storage device, a first receiving device, and a first transmitting device. The first data storage device is for storing data from the sensor. The first transmitting device is for transmitting data derived from the sensor. The apparatus also includes a single control unit. The single control unit includes a second receiving device, a second transmitting device, and a second data storage device. The second receiving device is for receiving data transmitted from the network of sensing units. The second data storage device is for storing the data received from the network of sensing units. The sensing units of the network of sensing units are each configured so a real time signal triggers a change in at least one from the group consisting of: (a) sensor data handling, (b) sensor data collection, (c) sensor data storage in the sensing unit, and (d) sensor data transmission to the single control unit.

Network monitoring device, bus system monitoring device, method and program

Abstract: A network monitoring device that monitors a network that transmits data via multiple repeaters is equipped with a monitoring frequency recording unit (111) where the monitoring frequency of the transmission status of each of the repeaters is recorded, a selection probability generating unit (112) that generates selection probability information, which is a specified probability value for each of the repeaters, a monitored subject specifying unit (113) that specifies a repeater for which transmission status is to be monitored in accordance with the monitoring frequency and the selection probability information, a transmission status acquisition unit (106) that acquires transmission status information representing the transmission status in the specified repeater, a transmission status recording unit (107) that records the transmission status information, an activity level calculation unit (109) that calculates an activity level representing the accuracy of the monitoring of transmission status for each repeater from the transmission status information, and a monitoring frequency updating unit (110) that updates the monitoring frequency based on the activity level. Throughput variation in the data transmission paths is thus sensed with high responsiveness.

A 10.8 mW Body Channel Communication/MICS Dual-Band Transceiver for a Unified Body Sensor Network Controller

Abstract: With the increasing number of portable and implantable personal health care devices, there is a strong demand to control their communication in a single wireless network. Recently, the IEEE 802.15 WBAN task group has discussed the combining of wearable and implantable body sensor networks (BSNs) [1], but no real chip implementation has been reported. In this paper, the implementation of a unified BSN as shown in Fig. 24.9.1 is described.. The unified BSN combines low-power body-channel communication (BCC) [2] and versatile medical implant communication service (MICS) [3] using a network controller located on the human body. This unified BSN has 2 main advantages over the conventional BSNs. First, the MICS band antenna shared with the BCC electrode can be attached directly to human skin to shorten the communication distances among the controller and implanted radios, relaxing their sensitivity and selectivity requirements. Second, due to low path loss of the human body channel, low-power communication is possible among the wearable devices [4]. In addition, the on-body sensors do not need external antennas because the bio-signal sensing electrode functions as the interface for data transmission.

Impact of LED Nonlinearity on Discrete Multitone Modulation

Abstract: In the context of communications based on light-emitting diodes (LEDs), spectrally efficient modulation has been considered for overcoming their limited bandwidth, and one scheme under investigation is quadrature-amplitude modulation on discrete multitones. The dependence of the output optical power on the driving current of practical LEDs is nonlinear, which distorts the transmitted signal. We investigate the impact of the nonlinear LED transfer function, i.e., the dependence of the emitted optical power on the driving current, on discrete multitone modulation. The effect incurred by this distortion was analyzed by using detailed numerical simulations addressing the impact of clipping, individual subcarriers, signal-to-noise ratio, and bit-error ratio. The approach was generalized to describe the impact of the nonlinearity of arbitrary LEDs and laser diodes, resulting in a powerful tool for assessing the impact of the nonlinearity on the link performance. This approach was applied to three types of LED, showing anything from a minuscule effect to the case in which error-free data transmission is made impossible by the transfer-function nonlinearity.

Advances in Theory and Application of Compressed Sensing

Abstract: Sampling is the bridge between analog source signal and digital signal.With the rapid progress of information technologies,the demands for information are increasing dramatically.So the existing systems are very difficult to meet the challenges of high speed sampling,large volume data transmission and storage.How to acquire information in signal efficiently is an urgent problem in electronic information fields.In recent years,an emerging theory of signal acquirement——compressed sensing(CS) provides a golden opportunity for solving this problem.This paper reviews the theoretical framework and the key technical problems of compressed sensing and introduces the latest developments of signal sparse representation,design of measurement matrix and reconstruction algorithm.Then this paper also reviews several open problems in CS theory and discusses the existing difficult problems.In the end,the application fields of compressed sensing are introduced.

Digital Current Controller for a 1 MHz, 10 kW Three-Phase VIENNA Rectifier

Abstract: Active three-phase rectifiers operated at switching frequencies of 500 kHz and above, in order to increase their power density, require high-speed current controllers. If these current controllers are implemented purely digitally, which is well established today for 20-200 kHz converter systems, then very high numerical data processing demands result. In this paper, two different types of field-programmable gate arrays (FPGAs) are evaluated for realizing high-speed converter current control. For the implementation of such controllers, not only the FPGA has to be considered but rather the entire signal chain. Two alternative A/D interfaces (including high-speed low-voltage differential signaling data transmission) that are able to handle data sampling rates up to 25 MSa/s are verified. Subsequently, a digital current controller is designed and it is shown how hardware multiplier blocks of modern FPGAs can be used advantageously. Furthermore, the FPGA implementation of high-resolution pulsewidth modulation providing symmetrical pulse patterns for high switching frequencies is described. Measurements taken from a 10 kW VIENNA rectifier laboratory prototype finally demonstrate the high performance of the proposed control concept and show that a low mains current total harmonic distortion of 1.4% can be achieved for such ultrahigh switching frequency converters.

Method and apparatus for power control of first data transmission in random access procedure of fdma communication system

Abstract: Transmit power is controlled for a first uplink data transmission on Physical Uplink Shared Channel (PUSCH) during random access channel (RACH) procedure. Power control adjustment for the first PUSCH transmission is performed relative to the power spectral density used for successful PRACH transmission as adjusted for bandwidth difference, etc. The uplink Physical random access channel carries the RACH information that is transmitted by the user equipment (UE) during registrations or base station originated calls. A PRACH is composed of a number of preambles and a message portion. The preambles are a series of radio frequency power “steps” that increase in power according to the power step setting until the maximum number of preambles is reached or the base station acknowledges. Once the UE receives a positive indication, it transmits the message portion of the PRACH which consists of message data and control data with independent power gain control.