Receiver Antenna Research Articles

A Development of Satellite Communication Link Analysis Tool

In a Satellite communication system, a link budget analysis is the detailed investigation of signal gains and losses moving through a channel from a sender to receiver. It inspects the fading of passed on data signal waves due to the process of spreading or propagation, including transmitter and receiver antenna gains, feeder cables, and related losses. The extent of the proposed tool is to make an effective, efficient, and user-friendly approach to calculate link budget analysis. It is also related to the satellite communication correlation framework by building up a graphical interface link analysis tool utilizing STK® software with the interface of C# programming. It provides better kinds of graphical display techniques, exporting and importing data files, printing link information, access data, azimuth-elevation-range (AER), and simulation is also possible at once. The components of the link budget analysis tool include transmitter gain, effective isotropic radiated power (EIRP), free space loss, propagation loss, frequency Doppler shift, flux density, link margin, elevation plot, etc. This tool can be useful for amateur users (e.g., CubeSat developers in the universities) or nanosat developers who may not know about the RF communication system of the satellite and the orbital mechanics (e.g., orbit propagators) principle used in the satellite link analysis.

Expedited Stroke Imaging With Electromagnetic Polar Sensitivity Encoding

There is a significant demand for fast and accurate electromagnetic (EM) imaging of stroke in emergency situations. This article presents a method for encoding the raw S-parameters from the Cartesian matrix to polar grid coordinates with weighting coefficients based on the receiver antenna spatial sensitivity. The polar sensitivity encoding (PSE) scheme is based on the fact that the receiver sensitivity generally has an encoding effect and, in this case, it is applied during the transformation of S-matrices to polar grid, which is geometrically congruent with the shape of the head. The PSE scheme alleviates the need for highly accurate and intricate forward and inverse EM field solvers and mitigates the introduction of numerical errors in addition to the unavoidable experimental uncertainties. The simulation and experimental results demonstrate that the PSE method is robust to head shifts up to about 5 mm and accurate in localizing strokes in less than a second.

Analysis of Selection Combining Receiver Performance for Time Successive SSK-M-ary Modulation

Space shift keying (SSK) is a single radio frequency (RF) chain multiple-input multiple-output (MIMO) scheme which uses the indices of transmit antennas for information transmission. Time successive SSK-M-ary modulation (TSSM) is a second order transmit diversity scheme based on single RF chain multiple antenna transmitter. In this letter, TSSM based on selection combining (TSSM-SC) is conceived to realize a single RF chain receiver for TSSM without compromise on the diversity order. The metric of receiver antenna selection is proposed for TSSM-SC. A novel approach is given to find a tight upper bound on the bit error rate (BER) of TSSM-SC in simple closed form. Further, the diversity order of TSSM-SC is analyzed with asymptotic expression. Simulation results that validate the analyses are given to show the diversity gain at reduced receiver complexity. The performance of TSSM-SC is compared with other schemes with selection combining to highlight its performance advantage.

A GPS Spoofing Detection and Classification Correlator-Based Technique Using the LASSO

This work proposes a global navigation satellite system (GNSS) spoofing detection and classification technique for single antenna receivers. We formulate an optimization problem at the baseband correlator domain by using the Least Absolute Shrinkage and Selection Operator (LASSO). We model correlator tap outputs of the received signal to form a dictionary of triangle-shaped functions and leverage sparse signal processing to choose a decomposition of shifted matching triangles from said dictionary. The optimal solution of this minimization problem discriminates the presence of a potential spoofing attack peak by observing a decomposition of two different code-phase values (authentic and spoofed) in a sparse vector output. We use a threshold to mitigate false alarms. Furthermore, we present a variation of the minimization problem by enhancing the dictionary to a higher-resolution of shifted triangles. The proposed technique can be implemented as an advanced fine-acquisition monitoring tool to aid in the tracking loops for spoofing mitigation. In our experiments, we are able to distinguish authentic and spoofer peaks from synthetic data simulations and from a real dataset, namely, the Texas Spoofing Test Battery (TEXBAT). The proposed method achieves 0.3% detection error rate (DER) for a spoofer attack in nominal signal-to-noise ratio (SNR) conditions for an authentic-over-spoofer power of 3 dB.

Overview of CODE’s MGEX solution with the focus on Galileo

We present an update on the multi-GNSS orbit and clock solution (COM), the CODE analysis center provides to the International GNSS service (IGS) in the frame of the multi-GNSS extension (MGEX). In recent years substantial progress was achieved in the fields of orbit modelling (Earth albedo, transmit antenna thrust, thermal radiation, eclipse attitude law), receiver and transmitter antenna calibration, ground tracking network, data dissemination, completeness of satellite constellations, availability of spacecraft-related meta information, observation biases, and ambiguity resolution. This led to improvements in orbit and clock parameter estimation, which are substantial for the European GNSS Galileo and are to a large part attributed to the availability of disclosed spacecraft meta data. Orbit and clock validation of the COM results using different validation methods (SLR residuals, orbit misclosures, linear fit of clock corrections) indicate that the quality of the updated Galileo products is meanwhile on the same level as for corresponding GPS and GLONASS products. Based on these achievements CODE decided to include Galileo in its IGS Rapid and Ultra-Rapid products and to contribute to the third reprocessing effort of the IGS with a three-system solution including GPS, GLONASS, and Galileo.

A Compact, Monostatic, Co-Circularly Polarized Simultaneous Transmit and Receive (STAR) Antenna With High Isolation

A compact, high-isolation, monostatic, co-circularly polarized (CP) simultaneous transmit and receive (STAR) antenna with similar radiation patterns is presented. The proposed antenna system consists of a sequentially rotated array (SRA) of four dual-polarized antenna elements and two quadrature feeding networks. The four transmit (TX)/receive (RX) ports of the STAR antennas are fed with equal amplitude and relative phase values of 0°, –90°, –180°, and –270° to generate identical right-handed CP for both TX and RX channels. The array element spacing to maximize the radiation performance of the STAR antenna is investigated. Two feeding networks with low phase and amplitude errors are designed based on the sensitivity analysis of the TX/RX isolation to realize high TX/RX isolation. The whole antenna system is integrated into one radio frequency (RF) front-end module using multilayer printed circuit board (PCB) technology. The proposed antenna has a compact size of 122.36 mm (1 λ 0) × 122.36 mm (1 λ 0) × 4 mm (0.03 λ 0), and exhibits more than 40.6 dB TX/RX isolation and better than 1.1 dB axial ratio (AR) over the 2.4–2.5 GHz band in the measurements.

Reconstruction of Clipped Signals in Quantized Uplink Massive MIMO Systems

This paper considers the uplink of a single-cell multiuser massive multiple-input multiple-output system. Each receiver antenna of the base station (BS) is assumed to be equipped with a pair of analog-to-digital converters to quantize the real and imaginary part of the received signal. We propose a novel clipping-aware receiver (CA-MMSE), which performs minimum mean square error (MMSE) reconstruction only on the clipped received samples, while the granular samples are left unchanged after the quantization. On this basis, we present an iterative algorithm to implement the CA-MMSE receiver and derive a sufficient condition for its geometrical convergence to a fixed point. We show that as long as the number of BS antennas or the quantization resolution is sufficiently high, then, the performance of the CA-MMSE is as good as the optimal MMSE receiver which reconstructs all quantized received symbols. Additionally, we propose a novel Bussgang-based weighted zero-forcing (B-WZF) receiver which distinguishes the clipping and granular distortion and it is shown that as long as the received training symbols per antenna are correlated, the CA-MMSE brings significant improvements compared to conventional receivers in the literature while for users that do not experience deep large-scale fading the simpler B-WZF is near to the CA-MMSE for sufficiently high signal-to-noise ratio and quantization resolution.

Implementing an IoT based Remotely Controlled Antenna Positioning System

wireless communication systems rely on antennas for signal reception. Proper placement of antennas is important to achieve successful wireless communication according to satellites / transmitters. Manual antenna changes are often risky in a way that usually results in unexpected accidents and can lead to death. To determine its position, the sensors are mounted on the antenna, and the motors change their position. Because the location of a transmitting station changes over time, antenna path must also be changed accordingly. This system will track the location of the antennas and provide new coordinates for the antenna positioning. Correctly position antenna is done by this system. We are therefore proposing an IOT based antenna positioning system that enables antennas to be placed remotely based on IOT. The paper explains how to implement the current and evolving technologies in Antenna Positioning. We can essentially use this device to place antennas respectively in the desired direction using IoT.

High Quality Zenith Tropospheric Delay Estimation Using a Low-Cost Dual-Frequency Receiver and Relative Antenna Calibration

The recent release of consumer-grade dual-frequency receivers sparked scientific interest into use of these cost-efficient devices for high precision positioning and tropospheric delay estimations. Previous analyses with low-cost single-frequency receivers showed promising results for the estimation of Zenith Tropospheric Delays (ZTDs). However, their application is limited by the need to account for the ionospheric delay. In this paper we investigate the potential of a low-cost dual-frequency receiver (U-blox ZED-F9P) in combination with a range of different quality antennas. We show that the receiver itself is very well capable of achieving high-quality ZTD estimations. The limiting factor is the quality of the receiving antenna. To improve the applicability of mass-market antennas, a relative antenna calibration is performed, and new absolute Antenna Exchange Format (ANTEX) entries are created using a geodetic antenna as base. The performance of ZTD estimation with the tested antennas is evaluated, with and without antenna Phase Center Variation (PCV) corrections, using Precise Point Positioning (PPP). Without applying PCVs for the low-cost antennas, the Root Mean Square Errors (RMSE) of the estimated ZTDs are between 15 mm and 24 mm. Using the newly generated PCVs, the RMSE is reduced significantly to about 4 mm, a level that is excellent for meteorological applications. The standard U-blox ANN-MB-00 patch antenna, with a circular ground plane, after correcting the phase pattern yields comparable results (0.47 mm bias and 4.02 mm RMSE) to those from geodetic quality antennas, providing an all-round low-cost solution. The relative antenna calibration method presented in this paper opens the way for wide-spread application of low-cost receiver and antennas.

On the Choice of the Third-Frequency Galileo Signals in Accelerating PPP Ambiguity Resolution in Case of Receiver Antenna Phase Center Errors

Rapid precise point positioning ambiguity resolution (PPP-AR) is of great importance to improving precise positioning efficiency. There is an expectation that Galileo multi-frequency (three or more frequencies) data processing will offer a promising way to accelerate PPP-AR. However, the performance of different combination observables out of raw Galileo multi-frequency data is still unclear, and the adverse impacts of missing receiver antenna phase center corrections have not been quantified in detail. We therefore studied uncombined Galileo PPP-AR by contrasting three typical triple-frequency combinations, which are E1/E5a/E5b, E1/E5a/E6, and E1/E5/E6 signals, using 30 days of data from 15 stations across Australia. We carried out triple-frequency PPP-AR by separately applying the official GPS receiver antenna phase centers, as currently employed in most relevant literatures, as well as the pilot Galileo receiver antenna phase centers preliminarily measured by the International GNSS Service. We found that, compared to dual-frequency (E1/E5a) PPP-AR, triple-frequency PPP-AR based on E1/E5a/E5b signals shortened the convergence time by only 7.6%, while those based on E1/E5a/E6 and E1/E5/E6 increased unexpectedly the convergence time by 17.6% and 12.7%, respectively, if the GPS receiver antenna corrections were presumed for Galileo signals. However, after using the pilot Galileo phase center corrections, triple-frequency PPP-AR based on E1/E5a/E5b, E1/E5a/E6, and E1/E5/E6 signals could speed up the convergence on average by about 16.2%, 30.3%, and 17.7%, respectively. Therefore, we demonstrate the critical impact of correct Galileo receiver antenna phase centers on multi-frequency PPP-AR convergences. Moreover, the triple-frequency signal combination E1/E5a/E6 is advantageous over others in achieving rapid triple-frequency Galileo PPP-AR.

DESIGN AND DEVELOPMENT OF TACTICAL MONITORING FORCE USING ONLINE BASED TELEMETRY SYSTEMS FOR MATAN BATALYON COMMANDO PASKHAS TEAM

The operational equipment of the Security and Rescue Team (Matan) of the Paskhas Command Battalion called the Integrated Personal Protection (IPP Set) is currently incomplete because monitoring of the implementation of the Matan Team's activities is limited to reports through radio / HT communication tools, so that in decision making actions by the Operations Commander Puskodalops is not optimal and accurate according to the conditions in the field. Therefore we need a system that can monitor the movements of the Matan Team that can monitor the position and visual forces in real time. This monitoring system using radio telemetry can transmit data in the form of GPS coordinates displayed by Google Map as well as visual image data recorded by FPV cameras in realtime using the 3DR telemetry transmission system 433 Mhz and VTX 5.8 Ghz mounted on a tactical helmet and received by ground station receiver antennas at Puskodalops, so that the position of the matan team personnel can be monitored and conditions in the field can be monitored in realtime so that the Operations Commander can make decisions more quickly, precisely and accurately according to field conditions.Keywords : Telemetry, Security and Rescue Team (Matan)

Fractal, Scale Free Electromagnetic Resonance of a Single Brain Extracted Microtubule Nanowire, a Single Tubulin Protein and a Single Neuron

Biomaterials are primarily insulators. For nearly a century, electromagnetic resonance and antenna–receiver properties have been measured and extensively theoretically modeled. The dielectric constituents of biomaterials—if arranged in distinct symmetries, then each vibrational symmetry—would lead to a distinct resonance frequency. While the literature is rich with data on the dielectric resonance of proteins, scale-free relationships of vibrational modes are scarce. Here, we report a self-similar triplet of triplet resonance frequency pattern for the four-4 nm-wide tubulin protein, for the 25-nm-wide microtubule nanowire and 1-μm-wide axon initial segment of a neuron. Thus, preserving the symmetry of vibrations was a fundamental integration feature of the three materials. There was no self-similarity in the physical appearance: the size varied by 106 orders, yet, when they vibrated, the ratios of the frequencies changed in such a way that each of the three resonance frequency bands held three more bands inside (triplet of triplet). This suggests that instead of symmetry, self-similarity lies in the principles of symmetry-breaking. This is why three elements, a protein, it’s complex and neuron resonated in 106 orders of different time domains, yet their vibrational frequencies grouped similarly. Our work supports already-existing hypotheses for the scale-free information integration in the brain from molecular scale to the cognition.

Receive Antenna Selection Under Discrete Inputs: Approximation and Applications

To analyze the achievable performance of antenna selection (AS) in practical multi-antenna systems, this paper studies the receive antenna selection (RAS) in single-input multiple-output (AS-SIMO) systems under discrete inputs. We first propose an approximate expression to evaluate the instantaneous mutual information (MI) of $M$ -ary quadrature amplitude modulation ( $M$ -QAM) signaling over additive white Gaussian noise (AWGN) channels. Then, by exploiting this approximate formula, we develop a closed-form formula for the ergodic MI in AS-SIMO systems with $M$ -QAM signaling. Additionally, we also analyze the asymptotic MI for a large number of receive antennas $N_{\mathrm{r}}$ . This asymptotic analysis suggests that the scaling rate of the MI with $N_{\mathrm{r}}$ becomes zero rate in contrast to the double logarithmic rate under Gaussian inputs. Besides, our result is also extended to discuss the mutual information of multiple-input multiple-output (MIMO) systems having discrete inputs with receive antenna selection, and an upper bound for the MI is derived. Finally, the derived result is applied to analyze several performance measures of the discrete inputs driven AS-SIMO systems. Specifically, it is first used to discuss the relationship between the ergodic MI and the number of active antennas. Our investigation shows that this relationship follows Pareto principle, i.e., 80% of the MI of full-antenna selection can be achieved via 20% of the total antennas. Then, our proposed approximation is employed to analytically study the effective MI which takes channel estimation (CE) into consideration, indicating that CE is a main limit of large-scale systems. Moreover, the energy efficiency (EE) is explored on the basis of our results, and we find there exists an optimal number of active antennas to maximize the energy efficiency. In addition to theoretical derivations, all the analytical results are validated by numerical simulations.

An Optimal Receive Antenna Selection Algorithm using GA in MIMO Communication System

MIMO technology offers large improvements in data transfer and connection range no bandwidth extra or processing potential in wireless communication,. Multiple transmitters and receivers are used to simultaneously transfer enormous amounts of data. Using many antennas transmitting and receiving, efficiency can be enhanced for wireless communication systems operating in fading environments. But the key downside in the new MIMO scheme, due to multiple Radio Frequency chains, is increased complexity and high cost. A daunting incentive is the development of techniques to reduce hardware and computing costs of the systems with a huge amount of antennas. The optimum selection of the receiver antenna subset is a very effective approach to achieving this goal. Genetic algorithm is used in this paper to choose the receivers from the available set of antennas that would then be compared with an existing receiving antenna selection process.

Secure Information Transmission with Self Jamming SWIPT

This article is focused on implementing simultaneous wireless information and power transmission as a physical layer security measure by using artificial noise. A series of high energy precoded symbols is simultaneously transmitted along with the information symbols over a Rayleigh frequency selective fading channel. The high energy precoded symbols act as an artificial noise for the eavesdroppers. The energy symbols are precoded on the basis of a legitimate user’s channel matrix to form a null space vector, which eliminates the interference of energy symbols at the information symbol receiver antennas, while allowing the rectenna to harvest energy from the superimposed information and energy symbols. We analyze the secrecy rate and error rate performance at the receiver under different circumstances, and we show that the performance of the legitimate user can be improved by using the iterative block decision feedback equalization method at the receiver.

Low-Cost and Low-Profile Phased Array Antenna for Satellite Reception Using Optimized Tracking Algorithm

In this paper, a stair-planar phased array antenna system for mobile broadcast satellite reception in Ku-band is proposed. The hybrid electromechanical tracking algorithm of this antenna system is designed for properly steering the antenna beam into the target satellite. The antenna sub-array elements are designed by using FR-4 epoxy and RO4003 to reduce the fabrication cost without considerable drop in the array efficiency. The genetic algorithm optimization is used to achieve the optimum values for the element spacing and feed positions, also. This array is fabricated, tested and compared with the simulation results to prove the idea. After that, the selected array is expanded to the main sub-array (2 × 32) and the main antenna array composed of 640 microstrip elements (10 main sub-arrays with 64 elements in each sub-array) with 32.5-dB gain at operating frequency, 11.9 GHz. This system can cover 30°–70° in elevation and 360° in azimuth planes by using the hybrid tracking algorithm to track different target satellites. This system serves as an excellent low-cost and simple candidate for Ku-band satellite reception in steady and smoothly moving platforms such as trains.

On the Throughput of Interference-Based Wireless Powered Communications With Receive Antenna Selection

We propose an interference-based wireless powered communication system in which an energy constrained source harvests energy from a single dominant co-channel interferer and then transmits information to a destination equipped with N receive antennas. Assuming interference dominates noise power at the destination and the receive antenna that maximizes the signal-to-interference ratio is selected, we investigate the average throughput for the delay-limited and delay-tolerant transmission modes. In particular, we derive an analytical expression of the average throughput for the delay-limited transmission mode, and a precise lower bound on the average throughput for the delay-tolerant transmission mode. Furthermore, we derive simplified asymptotic expressions of the average throughput for both transmission modes assuming asymptotically large number of receive antennas (i.e., N → ∞). We use the obtained asymptotic expressions to derive insightful closed-form expressions for the optimal energy harvesting time, which maximizes the average throughput, for both transmission modes. We show that the throughput-optimal energy harvesting time for the delay-limited and the delay-tolerant transmission scale like O(1/√N) and O(1/log(N)), respectively, for asymptotically large N.

Human detection with and without weapon using LTE-based passive Forward Scattering Radar System

Firstly, radar is a system that has a radio transmitter that transmits radio waves, which will be received by a receiver, and it is used for detecting and locating objects. The passive radar system only receives signal from existing transmitters such as telecommunication antenna by using radio signal for tracking, detecting and so on. This experimental study was conducted with a human holding a weapon representing intruders that cross borders illegally into the country. Existing commercial telecommunication antenna was used as the transmitter transmitting the electromagnetic waves, and the system received the waves by using the receiver antenna. There are many techniques for a passive radar but in this case, we used the forward scattering region to detect human with and without weapon. The Doppler signature from human detection is produced when the receiver antenna detects any presence of a human that passes through between the transmitter and receiver. Two LTE frequencies used in this experimental work were 1.8 GHz and 2.63 GHz with several providers and have wider LTE coverage. The data from human detection was collected using LTE based passive forward scattering radar system, and was then analysed using Matlab programme. Principal Component Analysis (PCA) was used to classify the human without weapon and human holding a weapon into two categories. This system successfully classified the human with and without weapon and could be used by the military for border protection.

Joint Beamforming Design and Receive Antenna Selection for Large-Scale MIMO Wiretap Channels

This paper investigates joint secure beamforming design and receive antenna selection problem for large-scale multiple-input-multiple-output (MIMO) wiretap channels. A Branch-And-Bound (BAB) based algorithm is utilized to search the optimal receive antenna subset under both perfect and imperfect channel state information (CSI) scenarios. First, for the perfect CSI scenario, we formulate the secrecy rate optimization problem, and an equivalent monotonically decreasing objective function is established to make the problem suitable for efficient BAB search. In each search, we propose using the weighted mean squared error minimization (WMMSE) method to tackle the optimization problem. Then, we generalize the framework to the imperfect CSI case, and the robust problem is designed to maximize the worst-case secrecy rate, the problem is challenging to solve due to the channel uncertainties. A cutting-set method is devised to solve this non-convex problem by updating the worst-case secrecy rate and channel uncertainties alternately. To reduce the design complexity, we also present an antenna selection based on the alternating optimization (AO) method. The validity of the proposed antenna selection algorithms is evaluated through numerical simulations.

Circular Planar Pac-man Antenna Toward Multiband Operations

A circular patch antenna with double slots has been proposed for multiple band applications. The proposed Pac-man antenna works in the range of C and X band. The antenna has been structured and broke down for FR4 substrate with dielectric constant of 4.4. This reception antenna can be utilized for wireless neighborhood (WLAN 2.324 GHz) applications, radar applications (9.484 GHz) and 4G applications (5.48 GHz). Moreover, a close by correlation of the proposed framework with the existing circular patch antenna is shown to check the precision of the proposed antenna. This plan has been demonstrated to upgrade the bandwidth and stretch out the task to numerous groups because of the nearness of “U”-formed opening in the patch. Likewise, the proposed plan is dissected regarding voltage standing wave ratio, gain and radiation design.