Showing papers on "Communications system published in 2014"

Scenarios for 5G mobile and wireless communications: the vision of the METIS project

Abstract: METIS is the EU flagship 5G project with the objective of laying the foundation for 5G systems and building consensus prior to standardization. The METIS overall approach toward 5G builds on the evolution of existing technologies complemented by new radio concepts that are designed to meet the new and challenging requirements of use cases today?s radio access networks cannot support. The integration of these new radio concepts, such as massive MIMO, ultra dense networks, moving networks, and device-to-device, ultra reliable, and massive machine communications, will allow 5G to support the expected increase in mobile data volume while broadening the range of application domains that mobile communications can support beyond 2020. In this article, we describe the scenarios identified for the purpose of driving the 5G research direction. Furthermore, we give initial directions for the technology components (e.g., link level components, multinode/multiantenna, multi-RAT, and multi-layer networks and spectrum handling) that will allow the fulfillment of the requirements of the identified 5G scenarios.

Survey on Free Space Optical Communication: A Communication Theory Perspective

Abstract: Optical wireless communication (OWC) refers to transmission in unguided propagation media through the use of optical carriers, i.e., visible, infrared (IR), and ultraviolet (UV) bands. In this survey, we focus on outdoor terrestrial OWC links which operate in near IR band. These are widely referred to as free space optical (FSO) communication in the literature. FSO systems are used for high rate communication between two fixed points over distances up to several kilometers. In comparison to radio-frequency (RF) counterparts, FSO links have a very high optical bandwidth available, allowing much higher data rates. They are appealing for a wide range of applications such as metropolitan area network (MAN) extension, local area network (LAN)-to-LAN connectivity, fiber back-up, backhaul for wireless cellular networks, disaster recovery, high definition TV and medical image/video transmission, wireless video surveillance/monitoring, and quantum key distribution among others. Despite the major advantages of FSO technology and variety of its application areas, its widespread use has been hampered by its rather disappointing link reliability particularly in long ranges due to atmospheric turbulence-induced fading and sensitivity to weather conditions. In the last five years or so, there has been a surge of interest in FSO research to address these major technical challenges. Several innovative physical layer concepts, originally introduced in the context of RF systems, such as multiple-input multiple-output communication, cooperative diversity, and adaptive transmission have been recently explored for the design of next generation FSO systems. In this paper, we present an up-to-date survey on FSO communication systems. The first part describes FSO channel models and transmitter/receiver structures. In the second part, we provide details on information theoretical limits of FSO channels and algorithmic-level system design research activities to approach these limits. Specific topics include advances in modulation, channel coding, spatial/cooperative diversity techniques, adaptive transmission, and hybrid RF/FSO systems.

The Tactile Internet: Applications and Challenges

Abstract: Wireless communications today enables us to connect devices and people for an unprecedented exchange of multimedia and data content. The data rates of wireless communications continue to increase, mainly driven by innovation in electronics. Once the latency of communication systems becomes low enough to enable a round-trip delay from terminals through the network back to terminals of approximately 1 ms, an overlooked breakthrough?human tactile to visual feedback control?will change how humans communicate around the world. Using these controls, wireless communications can be the platform for enabling the control and direction of real and virtual objects in many situations of our life. Almost no area of the economy will be left untouched, as this new technology will change health care, mobility, education, manufacturing, smart grids, and much more. The Tactile Internet will become a driver for economic growth and innovation and will help bring a new level of sophistication to societies.

Personal communication system to send and receive voice data positioning information

Abstract: A location tagged data provision and display system. A personal communication device (PCD) with electromagnetic communication capability has a GPS receiver and a display. The 10 PCD requests maps and location tagged data from data providers and other for display on the PCD. The data providers respond to requests by using searching and sorting schemes to interrogate data bases and then automatically transmitting data responsive to the requests to the requesting PCD.

Optimal Multiuser Transmit Beamforming: A Difficult Problem with a Simple Solution Structure [Lecture Notes]

Abstract: Transmit beamforming is a versatile technique for signal transmission from an array of antennas to one or multiple users [1]. In wireless communications, the goal is to increase the signal power at the intended user and reduce interference to nonintended users. A high signal power is achieved by transmitting the same data signal from all antennas but with different amplitudes and phases, such that the signal components add coherently at the user. Low interference is accomplished by making the signal components add destructively at nonintended users. This corresponds mathematically to designing beamforming vectors (that describe the amplitudes and phases) to have large inner products with the vectors describing the intended channels and small inner products with nonintended user channels.

Multipair Full-Duplex Relaying With Massive Arrays and Linear Processing

Abstract: We consider a multipair decode-and-forward relay channel, where multiple sources transmit simultaneously their signals to multiple destinations with the help of a full-duplex relay station. We assume that the relay station is equipped with massive arrays, while all sources and destinations have a single antenna. The relay station uses channel estimates obtained from received pilots and zero-forcing (ZF) or maximum-ratio combining/maximum-ratio transmission (MRC/MRT) to process the signals. To significantly reduce the loop interference effect, we propose two techniques: i) using a massive receive antenna array; or ii) using a massive transmit antenna array together with very low transmit power at the relay station. We derive an exact achievable rate expression in closed-form for MRC/MRT processing and an analytical approximation of the achievable rate for ZF processing. This approximation is very tight, particularly for a large number of relay station antennas. These closed-form expressions enable us to determine the regions where the full-duplex mode outperforms the half-duplex mode, as well as to design an optimal power allocation scheme. This optimal power allocation scheme aims to maximize the energy efficiency for a given sum spectral efficiency and under peak power constraints at the relay station and sources. Numerical results verify the effectiveness of the optimal power allocation scheme. Furthermore, we show that, by doubling the number of transmit/receive antennas at the relay station, the transmit power of each source and of the relay station can be reduced by 1.5 dB if the pilot power is equal to the signal power, and by 3 dB if the pilot power is kept fixed, while maintaining a given quality of service.

Radio base station, user terminal, and radio communication method

Abstract: The present invention is designed to improve spectral efficiency in a radio communication system which can use non-orthogonal multiple access (NOMA). Steps are provided in which a radio base station configures one of a plurality of transmission mode including a first transmission mode, which groups a plurality of transmission methods including a transmission method to employ non-orthogonal multiple access (NOMA) and multiple-user multiple-input and multiple-output (MU-MIMO), and a second transmission mode, which groups a plurality of transmission methods including a transmission method to employ this NOMA and open-loop transmit diversity, and transmits a downlink signal for this user terminal based on the configured transmission mode.

Visible light communications for 5G wireless networking systems: from fixed to mobile communications

Abstract: Visible light communication, considered as a potential access option for 5G wireless communications, is gaining extensive attention VLC has strengths in energy efficiency and ultra wide bandwidth, but also has weakness in transmission range and obstacles in transmission paths This article aims to provide a conclusive investigation of the latest progress in research on VLC, which can be used as part of 5G wireless communication systems This work highlights the strengths and weaknesses of VLC in comparison with RF-based communications, especially in spectrum, spatial reuse, security and energy efficiency The article also investigates various lighting sources proposed for VLC systems It summarizes the literature work on VLC networking into two categories: fixed and mobile VLC communications

Throughput Optimal Policies for Energy Harvesting Wireless Transmitters with Non-Ideal Circuit Power

Abstract: Characterizing the fundamental tradeoffs for maximizing energy efficiency (EE) versus spectrum efficiency (SE) is a key problem in wireless communication. In this paper, we address this problem for a point-to-point additive white Gaussian noise (AWGN) channel with the transmitter powered solely via energy harvesting from the environment. In addition, we assume a practical on-off transmitter model with non-ideal circuit power, i.e., when the transmitter is on, its consumed power is the sum of the transmit power and a constant circuit power. Under this setup, we study the optimal transmit power allocation to maximize the average throughput over a finite horizon, subject to the time-varying energy constraint and the non-ideal circuit power consumption. First, we consider the off-line optimization under the assumption that the energy arrival time and amount are a priori known at the transmitter. Although this problem is non-convex due to the non-ideal circuit power, we show an efficient optimal solution that in general corresponds to a two-phase transmission: the first phase with an EE-maximizing on-off power allocation, and the second phase with a SE-maximizing power allocation that is non-decreasing over time, thus revealing an interesting result that both the EE and SE optimizations are unified in an energy harvesting communication system. We then extend the optimal off-line algorithm to the case with multiple parallel AWGN channels, based on the principle of nested optimization. Finally, inspired by the off-line optimal solution, we propose a new online algorithm under the practical setup with only the past and present energy state information (ESI) known at the transmitter.

Towards THz Communications - Status in Research, Standardization and Regulation

Abstract: In the most recent years, wireless communication networks have been facing a rapidly increasing demand for mobile traffic along with the evolvement of applications that require data rates of several 10s of Gbit/s. In order to enable the transmission of such high data rates, two approaches are possible in principle. The first one is aiming at systems operating with moderate bandwidths at 60 GHz, for example, where 7 GHz spectrum is dedicated to mobile services worldwide. However, in order to reach the targeted date rates, systems with high spectral efficiencies beyond 10 bit/s/Hz have to be developed, which will be very challenging. A second approach adopts moderate spectral efficiencies and requires ultra high bandwidths beyond 20 GHz. Such an amount of unregulated spectrum can be identified only in the THz frequency range, i.e. beyond 300 GHz. Systems operated at those frequencies are referred to as THz communication systems. The technology enabling small integrated transceivers with highly directive, steerable antennas becomes the key challenges at THz frequencies in face of the very high path losses. This paper gives an overview over THz communications, summarizing current research projects, spectrum regulations and ongoing standardization activities.

Unmanned Aerial Vehicles for Power Line Inspection: A Cooperative Way in Platforms and Communications

Abstract: The emerging technology of unmanned aerial vehicle (UAV) has become more affordable and practicable for power line inspections. In this paper, we propose a multi-platform UAV system and multi-model communication system for highly efficient power line inspection tasks in China. The different UAVs cooperatively serve as long-distance imaging, short dis- tance imaging and communication relay. The high quality im- age/video is transmitted in realtime to the on-site control station for UAV navigation and far end office for analysis. Our experi- ence shows that the cooperative inspection for multi-UAVs can achieve a much higher efficiency than traditional inspection methods.  Index Terms—UAV, hexrotor, fixed wing, tethered rotor, pow- er line inspection, communication relay, datalink

Optical Vehicle-to-Vehicle Communication System Using LED Transmitter and Camera Receiver

Abstract: This paper introduces an optical vehicle-to-vehicle (V2V) communication system based on an optical wireless communication technology using an LED transmitter and a camera receiver, which employs a special CMOS image sensor, ie, an optical communication image sensor (OCI) The OCI has a “communication pixel (CPx)” that can promptly respond to light intensity variations and an output circuit of a “flag image” in which only high-intensity light sources, such as LEDs, have emerged The OCI that employs these two technologies provides capabilities for a 10-Mb/s optical signal reception and real-time LED detection to the camera receiver The optical V2V communication system consisting of the LED transmitters mounted on a leading vehicle and the camera receiver mounted on a following vehicle is constructed, and various experiments are conducted under real driving and outdoor lighting conditions Due to the LED detection method using the flag image, the camera receiver correctly detects LEDs, in real time, in challenging outdoor conditions Furthermore, between two vehicles, various vehicle internal data (such as speed) and image data (320 × 240, color) are transmitted successfully, and the 130-fps image data reception is achieved while driving outside

Multiple-input multiple-output (mimo) communication system

Abstract: A multiple-input multiple-output (MIMO) capable system is contemplated. The communication system may include a signal processor configured to separate an input stream into multiple signal paths to facilitate simultaneous transport through a communication medium. The capability to simultaneously transmit multiples signal paths may be beneficial in order to maximize throughput and/or minimize expense.

Social-aware D2D communications: qualitative insights and quantitative analysis

Abstract: With emerging demands for local area services, device-to-device communication is conceived as a vital component for the next-generation cellular networks to improve spectral reuse, bring hop gains, and enhance system capacity. Ripening these benefits depends on efficiently solving several main technical problems, including mode selection, resource allocation, and interference management. Aiming to establish a new paradigm for solving these challenging problems in D2D communication, in this article we propose a social-aware enhanced D2D communication architecture that exploits social networking characteristics for system design. By developing a profound understanding of the interplay between social networks' properties and mobile communication problems, we qualitatively analyze how D2D communications can benefit from social features, and quantitatively assess the achievable gains in a social-aware D2D communication system.

Methods and apparatus for device-to-device communications system

Abstract: A method includes configuring one or multiple pools of Device-to-Device (D2D) communication resources by an eNodeB (eNB). The method also includes signaling of the configured pool(s) of D2D communication resources by the eNB to a first User Equipment (UE) and a plurality of UEs using a common broadcast channel; and sending a request for one or multiple D2D communication resources to an eNB by the first UE configured to transmit D2D messages. The method also includes determining one or multiple resources for D2D communication by an eNB for the first UE. The method also includes communicating D2D resource allocation information to the first UE.

5G radio access

Abstract: Mobile communication has evolved significantly from early voice systems to today's highly sophisticated integrated communication platforms that provide numerous services, and support countless applications used by billions of people around the world.

Robust Networked Control Scheme for Distributed Secondary Control of Islanded Microgrids

Abstract: Distributed secondary control (DSC) is a new approach for microgrids (MGs) by which frequency, voltage, and power can be regulated by using only local unit controllers. Such a solution is necessary for anticipated scenarios that have an increased number of distributed generators (DGs) within the MG. Due to the constrained traffic pattern required by the secondary control, it is viable to implement a dedicated local area communication functionality among the local controllers. This paper presents a new wireless-based robust communication algorithm for the DSC of MGs. The algorithm tightly couples the communication and the control functionality, such that the transmission errors are absorbed through an averaging operation performed in each local controller, resulting in a very high reliability. Furthermore, transmissions from each DG are periodic and prescheduled broadcasts, and in this way, contention over the shared wireless medium is avoided. Real-time simulation and experimental results are presented in order to evaluate the feasibility and robustness endowed by the proposed algorithm. The results indicate that the proposed algorithm is very robust with respect to communication impairments, such as packet delays and random packet losses.

Vehicle-to-pedestrian communication system and method

Abstract: A system for alerting a user includes a first device for vehicle-to-pedestrian communication. The first device is operable by a pedestrian. The system further includes a vehicle operable by a driver including a second device for vehicle-to-pedestrian communication. The system is configured to provide an alert via at least one of the first device and second device to at least one of the driver and the pedestrian.

Design and Implementation of Color-Shift Keying for Visible Light Communications

Abstract: Color-shift keying (CSK) is a visible light communication intensity modulation scheme, outlined in IEEE 802.15.7, that transmits data imperceptibly through the variation of the color emitted by red, green, and blue light emitting diodes. An advantage of CSK is that the power envelope of the transmitted signal is fixed; therefore, CSK reduces the potential for human health complications related to fluctuations in light intensity. In this work, a rigorous design framework for high order CSK constellations is presented. A key benefit of the frame work is that it optimizes constellations while accounting for crosstalk between the color communication channels. In addition, and unlike previous approaches, the method is capable of optimizing 3-D constellations. Furthermore, a prototype CSK communication system is presented to validate the performance of the optimized constellations, which provide gains of 1–3 dB over standard 805.15.7 constellations.

Data communication systems and methods

Abstract: The present invention provides systems and methods for improved data communication between communication terminals such as a base station and an unmanned aerial vehicle. In some instances, the systems and methods described herein provide robust transmission uplink data such as control data and wideband transmission of downlink data such as image data or other sensor data, while avoiding interference between the uplink data transmission and the downlink transmission.

System and method of relay communication with electronic beam adjustment

Abstract: The invention relates to millimeter-wave point-to-point communication systems. A system comprises two separated millimeter-wave transceivers which provide high throughput data transmission and reception in frequency duplex mode and use high gain antennas capable of electronic scanning in some continuous angle range provided by the control module that implement control algorithms for antenna radiation pattern. Also a method based on the exploitation of scanning antennas of initial beam directions fine adjustment and subsequent beam directions tracking and readjustment when needed is proposed. The proposed system and method provide automatic recovery of failed connection in case of relay station orientation change due to influence of various external factors (wind, vibration, different intensity of heating of the bracing mountings at different time of a day and others) and can be used in backhaul systems of base station sites for mobile networks.

Designing multi-user MIMO for energy efficiency: When is massive MIMO the answer?

Abstract: Assume that a multi-user multiple-input multiple-output (MIMO) communication system must be designed to cover a given area with maximal energy efficiency (bits/Joule). What are the optimal values for the number of antennas, active users, and transmit power? By using a new model that describes how these three parameters affect the total energy efficiency of the system, this work provides closed-form expressions for their optimal values and interactions. In sharp contrast to common belief, the transmit power is found to increase (not decrease) with the number of antennas. This implies that energy efficient systems can operate at high signal-to-noise ratio (SNR) regimes in which the use of interference-suppressing precoding schemes is essential. Numerical results show that the maximal energy efficiency is achieved by a massive MIMO setup wherein hundreds of antennas are deployed to serve relatively many users using interference-suppressing regularized zero-forcing precoding.

Systems and methods for multi-user multi-lingual communications

Abstract: Various embodiments described herein facilitate multi-lingual communications. The systems and methods of some embodiments enable multi-lingual communications through different modes of communication including, for example, Internet-based chat, e-mail, text-based mobile phone communications, postings to online forums, postings to online social media services, and the like. Certain embodiments implement communication systems and methods that translate text between two or more languages. Users of the systems and methods may be incentivized to submit corrections for inaccurate or erroneous translations, and may receive a reward for these submissions. Systems and methods for assessing the accuracy of translations are described.

Radar sensing and emergency response vehicle detection

Abstract: A system for vehicle to another party communications that includes a vehicle personality module adapted to create a vehicle personality and a communications system that utilizes the created vehicle personality for one or more communications instead of a user's profile. The one or more communications are associated with one or more of an identifier and an icon representing the vehicle personality, with this identifier and/or icon sent with at least one communication and displayable to the recipient of the communication.

Communication Information Structures and Contents for Enhanced Safety of Highway Vehicle Platoons

Abstract: Highway platooning of vehicles has been identified as a promising framework in developing intelligent transportation systems. By autonomous or semi-autonomous vehicle control and intervehicle coordination, an appropriately managed platoon can potentially offer enhanced safety, improved highway utility, increased fuel economy, and reduced emissions. This paper is focused on quantitative characterization of the impact of communication information structures and contents on platoon safety. By comparing different information structures that combine front sensors, rear sensors, and wireless communication channels, as well as different information contents such as distances, speeds, and drivers' actions, we reveal a number of intrinsic relationships between vehicle coordination and communications in platoons. Typical communication standards and related communication latency are used as benchmark cases in this paper. The findings of this paper provide useful guidelines in sensor selections, communication resource allocations, and vehicle coordination.

Street lighting communications, control, and special services

Abstract: A smart street lighting system and method employs a plurality of street lights having a luminaire, a luminaire associate and a support pole. A communications module is contained within the luminaire associates and a power line is contained within the support poles. The power line is coupled to the communications module, the luminaire associate and the luminaire, and a steerable millimeter wave radar operatively coupled to the communications module. The communications module operates in a radio frequency network in a frequency range of 57-64 GHz. The steerable millimeter wave radar provides a signal reflected from a target that may be received by one of the luminaire associates within the system. A powerline communications system interfaces with the radio frequency network to provide communications between the communications modules in the street lights and the PLC system.

On Covert Acoustical Mesh Networks in Air

Abstract: Covert channels can be used to circumvent system and network policies by establishing communications that have not been considered in the design of the computing system. We construct a covert channel between different computing systems that utilizes audio modulation/demodulation to exchange data between the computing systems over the air medium. The underlying network stack is based on a communication system that was originally designed for robust underwater communication. We adapt the communication system to implement covert and stealthy communications by utilizing the ultrasonic frequency range. We further demonstrate how the scenario of covert acoustical communication over the air medium can be extended to multi-hop communications and even to wireless mesh networks. A covert acoustical mesh network can be conceived as a meshed botnet or malnet that is accessible via inaudible audio transmissions. Different applications of covert acoustical mesh networks are presented, including the use for remote keylogging over multiple hops. It is shown that the concept of a covert acoustical mesh network renders many conventional security concepts useless, as acoustical communications are usually not considered. Finally, countermeasures against covert acoustical mesh networks are discussed, including the use of lowpass filtering in computing systems and a host-based intrusion detection system for analyzing audio input and output in order to detect any irregularities.

Device-to-Device Communications for National Security and Public Safety

Abstract: Device-to-device (D2D) communications have been proposed as an underlay to long-term evolution (LTE) networks as a means of harvesting the proximity, reuse, and hop gains. However, D2D communications can also serve as a technology component for providing public protection and disaster relief (PPDR) and national security and public safety (NSPS) services. In the United States, for example, spectrum has been reserved in the 700-MHz band for an LTE-based public safety network. The key requirement for the evolving broadband PPDR and NSPS services capable systems is to provide access to cellular services when the infrastructure is available and to efficiently support local services even if a subset or all of the network nodes become dysfunctional due to public disaster or emergency situations. This paper reviews some of the key requirements, technology challenges, and solution approaches that must be in place in order to enable LTE networks and, in particular, D2D communications, to meet PPDR and NSPS-related requirements. In particular, we propose a clustering-procedure-based approach to the design of a system that integrates cellular and ad hoc operation modes depending on the availability of infrastructure nodes. System simulations demonstrate the viability of the proposed design. The proposed scheme is currently considered as a technology component of the evolving 5G concept developed by the European 5G research project METIS.

Adaptive Postdistortion for Nonlinear LEDs in Visible Light Communications

Abstract: In a visible light communications (VLC) system, the light emitting diode (LED) is the majorsource of nonlinearity. The nonlinear effects in the VLC system are different from the conventionalwireless communications system. The channel separation in the VLC system is significantly largerthan the signal bandwidth, thus the adjacent channel interference (ACI) is not an issue. Predistortiontechnique may not be a cost-efficient approach as it needs additional feedback physical circuits atthe transmitter. In this paper, we propose a post-distortion technique to estimate and compensatefor the LED’s nonlinearity at the receiver. The post-distortion technique only needs some additionalcomputational resources. In addition, the proposed approach significantly improves the error vectormagnitude (EVM) and bit-error-rate (BER) performance of the VLC system. Simulation results validatethe theoretical analysis.Index Terms: VLC, nonlinearity, memory effects, Wiener model, post-distortion, memory polynomialmodel.