Showing papers on "Active antenna published in 2015"

Differential Spatial Modulation

Abstract: Spatial modulation (SM) is a newly emerging multiple-input–multiple-output technique that activates only a single antenna for transmission at any time instant and uses the index of the active antenna as an additional information-carrying mechanism. However, by its nature, SM decoding is coherent in that channel state information (CSI) is required at the receiver. In fact, coherent SM decoding can be very complex due to the heavily entangled channel estimation and symbol detection. In this correspondence, a differential SM scheme that completely bypasses any CSI at the transmitter or receiver, while preserving the single active transmit antenna property, is developed. The proposed scheme can be applied to any constant energy constellation such as phase-shift keying (PSK) and to systems with arbitrary numbers of transmit and receive antennas. Simulation results are presented under various system configurations. With the same spectral efficiency, the proposed scheme is capable of paying no more than 3 dB of signal-to-noise ratio penalty compared with coherent SM and outperforming the single-antenna differential PSK and differential space–time coding schemes.

Enhanced Spatial Modulation With Multiple Signal Constellations

Abstract: In this paper, we introduce a new spatial modulation (SM) technique using one or two active antennas and multiple signal constellations. The proposed technique, which we refer to as Enhanced SM or ESM, conveys information bits not only by the index(es) of the active antenna(s), but also by the constellations transmitted from each of them. The main feature of ESM is that it uses a primary signal constellation during the single active antenna periods and some other secondary constellations during the periods with two active transmit antennas. The secondary signal constellations are derived from the primary constellation by means of geometric interpolation in the signal space. We give design examples using two and four transmit antennas and QPSK, 16QAM, and 64QAM as primary modulations. The proposed technique is compared to conventional SM as well as to spatial multiplexing (SMX), and the results indicate that in most cases, ESM provides a substantial performance gain over conventional SM and SMX while reducing the maximum-likelihood (ML) decoder complexity.

Signaling adapted csi-rs periodicities in active antenna systems

Abstract: A method in a network node (115) is disclosed. The method comprises grouping (704) a plurality of antenna ports (15) corresponding to a plurality of channel state information reference signals (CSI-RS) into at least a first CSI-RS antenna port group and a second CSI-RS antenna port group, and determining (708), based at least in part on one or more criteria, a first transmission periodicity for the first CSI- RS antenna port group and a second transmission periodicity for the second CSI-RS antenna port group. The method further comprises transmitting (712), to one or more user equipment (110), the CSI- RS corresponding to the antenna ports in the first CSI-RS antenna port group according to the determined first transmission periodicity, and transmitting (716), to the one or more user equipment (110), the CSI-RS corresponding to the antenna ports in the second CSI-RS antenna port group according to the determined second transmission periodicity.

A Novel Method for Calibrating Deployed Active Antenna Arrays

Abstract: This study proposes a simple self-calibration system that involves applying the phase-match method (PMM) in the far-field calibration of a deployed active array. When the proposed self-calibration approach is employed, an antenna array system can be maintained at a ground-based station, and no expensive and complex test equipment is required. An EM-based simulation method was applied to validate the proposed method numerically. Finally, an eight-element microstrip array operating at 3.6 GHz was designed to study the proposed method experimentally. The measured results validated the effectiveness of the proposed method in calibrating deployed antenna array systems.

2D active antenna array operation for wireless communication systems

Abstract: A method for operating a large scale antenna array in a wireless communication system includes receiving one or more signals. The one or more signals include information for beamforming to a plurality of user equipments (UEs) using a full-dimensional multiple-input multiple-output (FD-MIMO) beamforming scheme. The FD-MIMO beamforming scheme includes same time resources and same frequency resources that are co-scheduled to the plurality of UEs. The method further includes identifying a time delay of the one or more signals associated with one or more antenna arrays that are distributed in the large scale antenna array and performing a multi-user (MU) joint beamforming on the one or more signals to one or more UEs.

Reconfigurable UWB antenna with electrically control for triple on‐demand rejection bandwidth

Abstract: A varactor diode reconfigurable ultra-wideband antenna that with electrically controlling the rejects on-demand WiMAX, WLAN, and C-BAND signals in the entire 3.1–10.3 GHz range is presented. The antenna design, embedding the active devices, integration with the varactor diode, and biasing network are described. A method to vary the rejection on-demanded bandwidth is also provided. The fabrication prototype is conformal and double-sided. Results indicate a successful integration and minimal interference of the varactor diode voltage and biasing circuitry with the antenna, paving the road for more integrated reconfigurable antenna on communication systems using active devices technology. © 2015 Wiley Periodicals, Inc. Microwave Opt Technol Lett 57:1894–1897, 2015

Micro spaceborne high dynamic GNSS receiver and navigation method thereof

Abstract: The invention discloses a micro spaceborne high dynamic GNSS receiver and a navigation method thereof. The receiver comprises an active antenna, a radio frequency front end processing module, a baseband signal digital processing module, a positioning solution module and a host computer monitoring interface. The navigation method comprises the steps that the active antenna converts a received GNSS electromagnetic wave signal into a current signal; the signal enters the radio frequency front end processing module through a band-pass filter, and undergoes amplification, frequency conversion, filtering and analog-to-digital conversion to finally acquire a digital intermediate frequency signal; the baseband signal digital processing module carries out capturing, tracking, bit synchronization and frame synchronization on the digital intermediate frequency signal to acquire a navigation measurement value and a navigation message; the positioning solution module carries out positioning solution to finally acquire the satellite information of a user; and the host computer monitoring interface displays a positioning observation value, the number of received satellites and the information of a PDOP value in real time. The micro spaceborne high dynamic GNSS receiver and the navigation method thereof have the advantages of high framework flexibility, rapid verification of an improved algorithm, low cost, small volume and light weight.

2D Active Antenna Array Design for FD-MIMO System and Antenna Virtualization Techniques

Abstract: Full dimension MIMO (FD-MIMO) is one of the key technologies presently studied in the 3GPP for the next generation long-term evolution advanced (LTE-A) systems By incorporating FD-MIMO into LTE/LTE-A systems, it is expected that system throughput will be drastically improved beyond what is possible in conventional LTE systems This paper presets details on the 2D active antenna array design for FD-MIMO systems supporting 32 antenna elements The FD-MIMO system allows for dynamic and adaptive precoding to be performed jointly across all antennas thus achieving more directional transmissions in the azimuth and elevation domains simultaneously, to a larger number of users Finally, we discuss 2D antenna array port virtualization techniques for creating beams with wide coverage, necessary for broadcasting signals to all users within a sector, such as the CRS (Common Reference Signal)

Multicast system radio resource optimal distribution method based on active antenna array model

Abstract: The invention discloses a multicast system radio resource optimal distribution method based on an active antenna array model. The method comprises the steps as follows: performing cluster processing to a user based on position information of the user and video request information estimated in current time period; calculating a horizontal azimuth angle and a vertical elevation angle of the central position of each user group according to the user cluster result and position information of each user group; accurately aligning the user group with a base station antenna beam; using an antenna model of an active antenna array and determining a channel gain model from the base station to the user; providing a carrier resource distribution model based on the target of maximizing throughput capacity; providing a user group clustering algorithm, and performing clustering processing to the user group according to the position information of the user group. On the basis of carrier distribution algorithm of maximizing the throughput capacity, the method of the invention improves spectrum effectiveness, resource utilization rate, system capacity and user performance.

Integrated two dimensional active antenna array communication system

Abstract: A base station (BS) capable of communication with a number of transmission points includes a processor configured to control a beamforming transmission or reception and an integrated antenna array system. The integrated antenna array system includes a baseband signal processing unit configured to perform baseband functions and disposed between the two sections. The integrated antenna array system also includes a plurality of physical antenna elements disposed in groups. Each of the groups includes an equal number of the plurality of physical antenna elements. The plurality of physical antenna elements are disposed symmetrically around the baseband signal processing unit.

Method to improve active antenna system performance in the presence of mutual coupling

Abstract: A method in a network node comprises receiving a first input signal from a baseband processing unit of a first antenna branch, receiving a second input signal from a baseband processing unit of a second antenna branch, determining a first and second compensation coefficient, applying the first compensation coefficient to the second input signal to generate a first output signal, applying the second compensation coefficient to the first input signal to generate a second output signal, outputting the first output signal to a first power amplifier of the first antenna branch, the first output signal compensating for a mutual coupling from the second antenna branch to the first antenna branch, and outputting the second output signal to a second power amplifier of the second antenna branch, the second output signal compensating for a mutual coupling from the first antenna branch to the second antenna branch.

Variable active antenna spatial modulation

Abstract: In this study, variable active antenna spatial modulation (VASM) technique, which allows the selection of any number of antennas (but not a constant number of active antennas) to transmit a symbol at the same signalling interval, is presented. In the first step of the development of VASM, antenna selection method is determined to use the minimum number of transmit antennas. Complexity analysis of maximum likelihood decoder is given for the new scheme. In the second step, to reduce the correlation effect, a novel antenna selection method called VASM improved (VASMi) that minimises the pairwise error probability is introduced for exponentially correlated channels. For 6, 8, and 10 bit/s/Hz spectral efficiencies, bit error rates are obtained and compared with spatial modulation (SM) and generalised SM (GSM) for different antenna and signal constellation configurations. VASMi outperforms SM and GSM in both uncorrelated and exponentially correlated multiple-input multiple-output channels for similar antenna configurations.

Point-to-point radio link variation at E-band and its effect on antenna design

Abstract: Radio propagation will strongly influence the design of the antenna and front-end components of E-band point-to-point communication systems. Based on the ITU rain model, the rain attenuation is estimated in a statistical sense and it is concluded that for backhaul links of 1–10 km, antennas with a gain of 49.5 dBi are required. Moreover, depolarization can be a limiting factor for backhaul systems that are employing orthogonal polarization in order to improve capacity. Antenna mast movement becomes a relevant problem due to the narrow beamwidth of the high gain antennas, which is around 0.7◦ . We propose to implement a focal plane array as feed for the parabolic reflector antenna. This is to tackle the mast movement by electronic beam steering and to increase EIRP by increasing the number of active antenna elements, and to assist the mechanical alignment during installation.

SQIF Antenna Measurement in Near Field

Abstract: We have been developing superconducting microwave (8-15 GHz bandwidth) magnetic field receiving antennas based on a two-dimensional (2D) Superconducting Quantum Interference Filter (SQIF) composed of bi-SQUID arrays. The 2D arrays are designed and fabricated using standard HYPRES niobium 4.5 kA/cm2 process. The designed non-uniformity in inductances of bi-SQUID cells produces a pronounced zero-field antipeak in the flux-voltage response curve. We select the active antenna operation point by applying an appropriate dc flux bias current to set it in the middle of the antipeak linear slope. We measured comparative responses of the antenna with the SQIF dc bias at ON and OFF states when irradiated by a microwave signal from four different conventional planar ring and patch antennas placed in the near field.

Active Antenna System And Method With Full Antenna Ports Dimension

Abstract: An Active Antenna System (AAS) operated as a static AAS is used to generate a static beam from signals applied to its input and based on received AAS configuration information. The AAS configuration information is received by a processor coupled to all of the components of the AAS and said processor converts the received AAS configuration information to control signals causing said components to generate the static beam.

Active MIMO antenna configuration for maximizing throughput in mobile devices

Abstract: An active antenna system and algorithm is proposed that provides for dynamic tuning and optimization of antenna system parameters for a MIMO system that will provide for greater throughput. As one or multiple antennas are loaded or de-tuned due to environmental changes, corrections to correlation and/or isolation are made by tuning the active antenna. A null-steering technique is implemented to alter the near-field and far-field characteristics to aid in modifying correlation and isolation in the multi-antenna system.

Analysis of thermal effects in active antenna array transmitters using a combined EM/circuit/thermal simulation technique

Abstract: This paper presents a new technique for efficient system level analysis of joint nonlinear thermal and RF effects in active antenna array transmitters. The technique is based on the integration of an electro-thermal simulation with comprehensive electro-magnetic (EM) and nonlinear temperature-dependent behavioral models for the active circuits. Simulation results for a 64 (8×8) element GaN-based antenna array MIMO transmitter serving two independent users are used to illustrate the predictive capabilities offered by the proposed analysis.

Reduced space channel feedback for FD-MIMO

Abstract: To support downlink full-dimension (FD-MIMO) in FDD scenarios, an accurate yet reasonably efficient channel-state-information (CSI) feedback scheme is required to harness the potential beamforming gain offered by the use of a large number of antenna elements in a 2D active antenna array. In this paper, a reduced-spaced channel quantization and feedback scheme which exploits slow variation of the angle-of-departure (AoD) distribution is proposed. By perceiving the instantaneous spatial channel to be a linear combination of slowly varying subset of matrices, it is demonstrated that the proposed scheme offers up to 62.5% dimensionality reduction with negligible throughput loss in 16-antenna FD-MIMO system. When used together with vector quantization, the proposed scheme offers substantial gain over that supported by 3GPP LTE.

Advances in antenna pattern-based MIMO OTA test methods

Abstract: This paper discusses recent developments with the two-stage MIMO OTA test method. It first introduces the concept of the two-stage method which is based on a first stage of antenna pattern measurement followed by a second stage of throughput measurement using a signal generated by convolving the device antenna pattern with the desired spatial channel model. The resulting signal is applied to the DUT either through a conducted or radiated connection. The radiated version of the two-stage method was approved by 3GPP in Technical Report 37.977 v12.0.0 [1]. The primary advantage of the two-stage method is that arbitrary 2D or 3D spatial channel models can be emulated without the need for the conventional multi-probe anechoic chamber approach which is significantly more complex and expensive. The extension of the two-stage method to active antenna systems was covered in [2]. This present paper will review recent two-stage work in CTIA and 3GPP including the specification of an antenna test function (ATF) in 3GPP Technical Report 36.978 [3] which has been designed with future flexibility for supporting higher order MIMO and carrier aggregation.

Ceiling assembly with integrated repeater antenna

Abstract: An active antenna may be installed within a ceiling assembly of a building to improve the range of a wireless and/or cellular network. Further, a ground plane may be installed throughout the ceiling to reduce the occurrence of multipath interference of radio frequency (RF) signals. In addition, one or more active and/or passive antennas may also be installed in the ceiling to further extend the range of the wireless and/or cellular network within the building. Each of the antennas may be designed to facilitate (RF) signal gain for a collection or range of frequencies. In some instances, the installation of active and/or passive antennas may increase the range of a communications network, while the installation of a ground plane throughout the ceiling may reduce the occurrence on multipath interference resulting in improved wireless and/or cellular network performance including increased bandwidth and range.

Two Dimensional Array of Layered Metal-Dielectric Sandwich Structures for Terahertz Applications

Abstract: In this paper, the design of a front end array for active antenna applications using metamaterial for usage in the terahertz frequency range is discussed. A brief analysis of the scattering parameters, dispersion curves and radiation patterns is done for composite right/left handed (CRLH) transmission line metamaterials that have a metal-dielectric-metal (MDM) layered configuration as their unit cell structure. An array of the same in one and two dimensions is analyzed in order to determine its electromagnetic properties.

Active antenna array beam optimization method based on tracking and prediction of user position

Abstract: The invention discloses an active antenna array beam optimization method based on tracking and prediction of a user position. Based on the active antenna user level beam forming technology, the accurate prediction and tracking of the user position are achieved, the information interaction between a base station of a user is effectively reduced, and the handling capacity of a system is improved though a beam optimization algorithm. By means of the active antenna array beam optimization method based on tracking and prediction of the user position, the tracking and prediction of the user position are accurately achieved, the information interaction between the base station and the user is reduced, the utilization rate of spectrum resources is increased, the system capacity and the user performance are improved, and the large user performance improvement is achieved. Meanwhile, beam optimization is conducted based on the total handling capacity in a cell, an optimized beam power allocation algorithm is proposed, and the system capacity is increased.

Active antenna associated device and system, and transmitting and receiving calibration method

Abstract: An active antenna associated device and system, and a transmitting and receiving calibration method, used for implementing extensible design of an antenna array, reducing construction implementation difficulty, and ensuring construction implementation reliability. The active antenna unit comprises: N active antenna arrays, a main calibration coupling circuit unit, a transmitting and receiving calibrating unit, a calibration parameter storage unit, and a radio over fiber (ROF) photoelectric conversion unit, wherein N is larger than 1. Each active antenna array at least comprises an antenna calibration coupling circuit unit and M antenna oscillators connected to the antenna calibration coupling circuit unit, wherein M is larger than 1. The antenna calibration coupling circuit units of the active antenna arrays are connected to the main calibration coupling circuit unit through a calibration radio frequency channel. The main calibration coupling circuit is connected with the transmitting and receiving calibrating unit. The transmitting and receiving calibrating unit and the calibration parameter storage unit are respectively connected to the ROF photoelectric conversion unit.

Linearization of active antenna array

Abstract: An transmitter arrangement and a method therein are provided for linearization of an active antenna array. The active antenna array comprises a plurality of antenna elements, which are associated with a plurality of power amplifiers. The active antenna array is further associated with a precoder, W, having a number of input and 5 output ports. The method comprises obtaining a first signal X1 provided to the antenna array via a first input port of the precoder W. The method further comprises adapting a pre-distorting linearizer connected to the first input port based on the first signal X1 and on feedback from the plurality of antenna elements, resulting from the propagation of X1 via the precoder W, and via the plurality of power amplifiers.10 Embodiments are also provided for adapting a pre-distorting linearizer based on a plurality of input signals, X1, X2, etc., and feedback from the plurality of antenna elements.

0.25µm BiCMOS system-on-chip with four transceivers for Ka-band active reflectarrays

Abstract: A highly complex mm-wave system-on-chip (SOC) for Ka-band active antenna arrays is presented, containing digital and mixed-signal circuits, RF-MEMS switches and four transceivers. In RX mode, 13.7dB of maximum gain with −21dBm IP1dB were obtained, in TX mode, 11dB of maximum gain with −2dBm OP1dB. A total of 65536 amplitude and phase states can be set. The IC has a total power consumption of 222mW in RX and 337mW in TX mode and occupies 4×3.85mm2.

Antenna and active antenna system

Abstract: The invention discloses an antenna and an active antenna system. The antenna and the active antenna system are used for lowering the complexity and power consumption of an antenna device and lowering the production cost. The antenna comprises an antenna array, a multichannel leading end, a multi-beam receiving network and a multi-beam transmitting network. An antenna array comprises w antenna oscillators, wherein the w is a natural number larger than or equal to 2. The multi-beam transmitting network is used for conducting beam forming processing on j-path transmitting signal beams, and m-path transmitting signals are obtained, wherein the j is a natural number. The multichannel leading end is used for converting the w-path first radio-frequency signals received by the w antenna oscillators into n-path receiving signals and converting the m-path transmitting signals of the multi-beam transmitting network into w-path second radio-frequency signals, wherein both the n and m are the natural number smaller than or equal to the w. The multi-beam receiving network is used for conducting beam forming processing on n-path receiving signals generated by the multichannel leading end, and k-path receiving signal beams are obtained, and the k is a natural number.

Power quality monitoring system

Abstract: The invention discloses a power quality monitoring system. According to the power quality monitoring system, communication between ARM (Advanced RISC Machines) and DSP (Digital Signal Processor) is achieved through a ZigBee wireless transmission module, complex wiring procedures are saved, a plenty of vigor and costs are saved, and various power quality parameters such as effective values, power, power factors, the harmonic distortion rate, the harmonic ratio, voltage fluctuation and flickering and three-phase imbalance can be measured. The power quality monitoring system has the advantages of being low in cost, high in reliability, high in capacity, simple in networking and applicable to real-time monitoring of power quality of automatic production line precise instrument and equipment in industrial zones, having practical meanings in productivity improvement, energy conservation and emission reduction of high-technology industrial zones, improving the stability and the detection accuracy of the integral device due to the fact that an active antenna and a passive antenna are arranged inside an antenna, a peripheral circuit is in a constant source current circuit design, and current fluctuation is avoided and meanwhile detecting the temperature of a storage battery.

K-band active antenna integrated with CMOS adaptive-bias power amplifier

Abstract: A K-band active antenna integrated with an adaptive-bias power amplifier (PA) is realized by 0.18-μm CMOS and GIPD technology. To minimize the loss resulting from the output matching network of the PA, the input impedance of the dipole antenna is designed to be the optimal load of that PA. The efficiency of the PA can be therefore improved significantly.

Reference signal sending method, reference signal receiving method, reference signal sending device and reference signal receiving device in active antenna system

Abstract: The invention discloses a reference signal sending method, a reference signal receiving method, a reference signal sending device and a reference signal receiving device in an active antenna system. CRS multi-antenna ports are adopted, and different CRS multi-antenna ports adopt different vertical-dimension beam forming vectors to realize antenna virtualization. A terminal reports CRS multi-antenna port information while reporting the RSPR value, and therefore, poor reporting of CRS signal coverage and RSRP in an active antenna system is avoided. Specifically, the beneficial effects as follows are achieved: (1) CRS and data transmission signal coverage difference based on CSI-RS or UE-RS are avoided or reduced; (2) the problem that a terminal accesses an inappropriate cell because CSI-RS or UE-RS and CRS adopt different vertical-dimension beam forming technologies is avoided or reduced; and (3) a terminal at a specific antenna height can be prevented from being in a spatial deep fading state of vertical-dimension antenna gain when receiving CRS, data signals modulated based on CRS, and control signals.

Active antenna array

Abstract: An ultra wideband active antenna platform can be deployed globally. A plug-and-play radio unit is removably attached to an outside of the active antenna. The PAPR can be removably plugged into a docking station to provide different technology or frequency bands specific for customers in different regions without the costly replacement of the whole antenna. In addition, the heat-generating sources (power amplifiers) with heavy heatsink structures are separated from the main antenna body, so that the whole active antenna can be installed separately since the installation weight of the antenna would be reduced.