Communication Receiver Research Articles

Design and FPGA Implementation of Relative Dynamics Measurement Techniques for Satellite Communication Systems

Performance of a satellite communication receiver is greatly affected by the relative dynamics scenario. Relative dynamics is related to the variable motion between communication source and destination systems. It encompasses relative acceleration and relative jerk. The paper presents the phase error-based measurement techniques for relative dynamics. Binary Phase Shift Keying (BPSK) demodulator is considered for development and verification of the techniques. Paper describes the requirement and design of 3rd order BPSK demodulator for measurement and handling relative jerk. System level simulation is carried out for different scenario. Design is coded in VHDL and realized on the Xilinx platform. Application of developed system in adaptive signal processing based BPSK demodulator is also dealt in detail.

On-chip integrated plasmon-induced high-performance self-powered Pt/GaN ultraviolet photodetector

The advantages of on-chip integrated photodetectors, such as miniaturization, high integration, and reliability, make them an indispensable and important part of electronic devices and systems. Herein, we experimentally exhibit a monolithically integrated ultraviolet photodetector utilizing GaN microcylinder epitaxial-structure on Si wafer, with its photoresponse properties plasmonically-boosted using Pt nanoparticles via specific sizes. When illuminated upon ultraviolet light at 0 V bias, the Pt/GaN device has significant photovoltaic performances, including a peak responsivity of 200.1 mA W-1, external quantum efficiency of 65% and other figures-of-merit. Finite element analysis and energy band theory confirm that the excellent photodetection properties of the Pt/GaN device are related to the strong plasmon absorption and the increase of hot electrons injected into the GaN conduction band, which make its photoresponse performance and robustness in application much better. To realize the multipurpose capability of the devices, we validate the application of Pt/GaN as turbidity sensing and achieve a resolution of up to 100 NTU. Moreover, the prepared devices can be used as optical data receivers for optical communication. These findings provide references for on-chip detectors to improve overall system performance and drive the realization of more complex applications.

Graphene Readout Silicon-Based Microtube Photodetectors for Encrypted Visible Light Communication.

The implementation of an advanced light receiver is imperative for the widespread application of visible light communication. However, the integration of multifunctional and high-performance visible light receivers is still limited by device structure and system complexity. Herein, a graphene-readout silicon-based microtube photodetector is proposed as the receiver for omnidirectional Mbps-level visible light communication. The integration of graphene-semiconductor material systems simultaneously ensures the effective absorption of incident light and rapid readout of photogenerated carriers, and the device exhibits an ultrafast response speed of 75ns and high responsivity of 6803AW-1. In addition, the microtube photodetector realizes the omnidirectional light-trapping and enhanced polarization photodetection. As the receiving end of the visible light communication system, the microtube photodetector achieves a data rate of up to 778Mbps, a field of view of 140°, and the encrypted visible light communication of polarized light, providing a new possibility for the future development of the internet of things and information security.

Multimode Fiber based Multi-OAM Mode Group Receiver for Turbulence-Resistant Free-Space Optical Communications

Multimode Fiber based Multi-OAM Mode Group Receiver for Turbulence-Resistant Free-Space Optical Communications

Rydberg-atom-based multiband frequency-hopping communication receiver using five-level atomic system

Rydberg-atom-based multiband frequency-hopping communication receiver using five-level atomic system

Advances in deep learning-based intelligent receivers

Abstract. This paper presents a summary of the progress of deep learning in the research of intelligent receivers and predicts its future development direction. First, the background of the era of intelligent receivers is introduced. With the rapid development of communication technology, intelligent receivers show insufficient flexibility, low accuracy, and spectral efficiency in detecting current radio signals. This is a challenge that is difficult to overcome in order to meet the needs of modern signal recovery. With the advent of artificial intelligence technologies such as deep learning, academia and industry began to explore the potential of applying these techniques to the field of communication receivers, leading to the emergence of intelligent receivers. This paper then introduces the fundamentals of wireless communication systems and deep learning neural networks, laying the groundwork for a deeper understanding of the subsequent content. Chapter 3 provides a comprehensive overview of the application of intelligent receivers in signal reception, including channel estimation, signal detection, modulation identification, demodulation and decoding. Finally, the paper considers the practical applications of intelligent receivers and speculates on their future development.

Publisher Correction: Rydberg states of alkali atoms in atomic vapour as SI-traceable field probes and communications receivers

Publisher Correction: Rydberg states of alkali atoms in atomic vapour as SI-traceable field probes and communications receivers

Transformer-empowered receiver design of OFDM communication systems

With deep learning, we perform channel estimation and signal detection in massive Multiple Input Multiple Output (MIMO)-Orthogonal Frequency Division Multiplexing (OFDM) systems in this paper. Specifically, we design and extend the basic framework of receivers for MIMO-OFDM systems in an end-to-end approach. A Transformer-based MIMO-OFDM receiver called TCD-Receiver is proposed, which introduces a multi-attention mechanism to learn the channel characteristics by introducing a generic and flexible Transformer network structure. The network parameters are updated based on the relationship between the received signal and the original signal, where the final signal information is obtained without explicit channel estimation and the predicted transmit bits are directly output. The experimental results show that the TCD-Receiver proposed can effectively solve the channel distortion and detect the transmitted signals compared with the traditional communication receivers, and its performance can be comparable to that of the traditional OFDM receivers, and it also has obvious advantages in combating the complex and difficult-to-model channel environment as well as the nonlinear interference factors.

Error performance analysis for OOK modulated optical camera communication systems

Integrating image sensors’ imaging capabilities into the receiver for visible light communication is a prominent characteristic of optical camera communication (OCC). However, the exposure effect during imaging distorts received waveforms and introduces inter-symbol interference (ISI), leading to decreased OCC reliability. This paper aims to provide an in-depth analysis of the impact of image sensor exposure effects on the error performance of OCC systems. Analytical expressions of the pixel signal-to-interference and noise ratio (PSINR) are derived using the pulse response function (PRF) for an on-off keying (OOK) modulated OCC system with varying exposure times. Furthermore, the bit error rate (BER) performance is evaluated analytically using PSINR, and a straightforward BER measurement scheme is proposed for experimental validation. Results from analyses and experiments conducted under different exposure times indicate that longer exposures lead to increased ISI and decreased PSINR, thereby increasing the error probability of data demodulation. Additionally, a combined impact of noise and exposure on OCC system reliability is observed, highlighting noise-limited and interference-limited characteristics under low and high signal-to-noise ratio (SNR) conditions, respectively. By utilizing PSINR as a bridge, this paper precisely analyzes OCC system reliability under exposure effects, laying a theoretical foundation for system design and optimization.

Rydberg states of alkali atoms in atomic vapour as SI-traceable field probes and communications receivers

Rydberg states of alkali atoms in atomic vapour as SI-traceable field probes and communications receivers

Underwater Acoustic Orthogonal Frequency-Division Multiplexing Communication Using Deep Neural Network-Based Receiver: River Trial Results.

In this article, a deep neural network (DNN)-based underwater acoustic (UA) communication receiver is proposed. Conventional orthogonal frequency-division multiplexing (OFDM) receivers perform channel estimation using linear interpolation. However, due to the significant delay spread in multipath UA channels, the frequency response often exhibits strong non-linearity between pilot subcarriers. Since the channel delay profile is generally unknown, this non-linearity cannot be modeled precisely. A neural network (NN)-based receiver effectively tackles this challenge by learning and compensating for the non-linearity through NN training. The performance of the DNN-based UA communication receiver was tested recently in river trials in Western Australia. The results obtained from the trials prove that the DNN-based receiver performs better than the conventional least-squares (LS) estimator-based receiver. This paper suggests that UA communication using DNN receivers holds great potential for revolutionizing underwater communication systems, enabling higher data rates, improved reliability, and enhanced adaptability to changing underwater conditions.

Non-verbal effecting - animal research sheds light on human emotion communication.

Cracking the non-verbal "code" of human emotions has been a chief interest of generations of scientists. Yet, despite much effort, a dictionary that clearly maps non-verbal behaviours onto meaning remains elusive. We suggest this is due to an over-reliance on language-related concepts and an under-appreciation of the evolutionary context in which a given non-verbal behaviour emerged. Indeed, work in other species emphasizes non-verbal effects (e.g. affiliation) rather than meaning (e.g. happiness) and differentiates between signals, for which communication benefits both sender and receiver, and cues, for which communication does not benefit senders. Against this backdrop, we develop a "non-verbal effecting" perspective for human research. This perspective extends the typical focus on facial expressions to a broadcasting of multisensory signals and cues that emerge from both social and non-social emotions. Moreover, it emphasizes the consequences or effects that signals and cues have for individuals and their social interactions. We believe that re-directing our attention from verbal emotion labels to non-verbal effects is a necessary step to comprehend scientifically how humans share what they feel.

Blame-Correct Support for Receiver Properties in Recursively-Structured Actor Contracts

Actor languages model concurrency as processes that communicate through asynchronous message sends.Unfortunately, as the complexity of these systems increases, it becomes more difficult to compose and integrate their components. This is because of assumptions made by components about their communication partners which may not be upheld when they remain implicit. In this paper, we bring design-by-contract programming to actor programs through a contract system that enables expressing constraints on receiver-related properties.Expressing properties about the expected receiver of a message, and about this receiver's communication behavior, requires two novel types of contracts.Through their recursive structure, these contracts can govern entire communication chains. We implement the contract system for an actor extension of Scheme, describe it formally, and show how to assign blame in case of a contract violation.Finally, we prove our contract system and its blame assignment correct by formulating and proving a blame correctness theorem.

The strength of sexual signals predicts same-sex pairing in two Coptotermes termites

Abstract Same-sex sexual behavior (SSB) is an enigma in behavioral ecology as it does not result in reproduction. Proximately, the effect of sexual signals on SSB could be distinct between signal receivers and senders. For receivers, the absence of sexual signals leads to smaller phenotypic sex differences, leading to frequent accidental SSB between receivers. Alternatively, for senders, sexual signals could help locate another sender, enhancing intentional SSB. Here, we demonstrate this link between sex pheromone signaling and the frequency of same-sex pairing in two Coptotermes termites that use the same chemical as sex pheromones but in different quantities. In termites, mating pairs engage in tandem runs, where a female emits sex pheromones to guide a male as they move together in searching a potential nest site. So, females are signal senders, and males are signal receivers for sexual communication. We found that female-female tandems were more stable in C. formosanus, whose females produce more pheromones. On the other hand, although both species did not show stable male-male tandems, males of C. gestroi, whose females produce fewer pheromones, spent more time attempting to follow another male. Thus, stronger pheromones lead to sender-sender SSB, while weaker pheromones lead to receiver-receiver SSB. The proximate mechanism of SSB is diverse according to the properties of sexual communications in heterosexual contexts.

Design and FPGA Implementation of Signal Strength Measurement Techniques for Satellite Communication Systems

Communication receivers perform three major functions, frequency down conversion, IF demodulation and subcarrier demodulation. The functioning of a receiver is mainly controlled by input signal strength and relative dynamics. Signal strength is measured in terms of Signal to Noise ratio (SNR) and Carrier to Noise power density (C/No). Any measure of signal strength indirectly gives information about receiver performance for that period. Apart from this, SNR measurement in close loop with Phase Locked Loop (PLL) parameter forms the adaptive PLL system, which is one of the driving forces for this paper. The focus of this paper is to find suitable signal strength measurement techniques and their implementation for satellite communication systems. Signal to Noise Variance method (SNV) and Narrow band Wide band Power Ratio (NWPR) methods are considered based on the performance and realization aspects. All techniques require division, logarithm, and multiplication functions for their realization in hardware. CO-ordinate Rotation Digital Computer (CORDIC) algorithm is considered for realizing logarithm function. A comparison study is done for developed algorithm with Intellectual Property (IP) core. Developed SNR techniques are simulated for Binary Phase Shift Keying (BPSK) demodulator system and performance is evaluated for Additive White Gaussian Noise (AWGN). The paper describes the FPGA design and simulations of these techniques. Developed design is targeted to commercial and space qualified FPGA platforms. FPGA implementations results are compared with system level simulation results, and both are found to be satisfactory. Application of developed system in adaptive BPSK demodulator is also presented.

An ultra-low power QCA based vedic multiplier for digital radar application

Quantum-dot cellular automata (QCA) is a promising nanotechnology that appears to meet the requirements of high speed radar applications. Due to its advantages, including its extremely low power dissipation and less occupied area, it is highly regarded. The multiplier module is an essential component in Phased Array Radar (PAR). In the real-time PAR based systems, many applications like digital beam forming, local oscillators, and communication receivers etc. requires multiplication operation. However, the most important factors in these systems are the area and power consumption. This paper presents an ultra-low power vedic multiplier using QCA technology, and it provides the effective clocking, reduce the number of cells, and low energy dissipation. The 4×4 vedic multiplier utilizes only 2940 cells and occupies 7.33μm2 area with 7.64×10−1eV of energy dissipation. The total consumed power of this module is 1.61nW. This architecture outperforms complementary metal-oxide-semiconductor (CMOS) based circuits in terms of power by 90%. The proposed contribution will initiate a new direction of research into real-time PAR based systems.

Quantum computer-enabled receivers for optical communication

Optical communication is the standard for high-bandwidth information transfer in today’s digital age. The increasing demand for bandwidth has led to the maturation of coherent transceivers that use phase- and amplitude-modulated optical signals to encode more bits of information per transmitted pulse. Such encoding schemes achieve higher information density, but also require more complicated receivers to discriminate the signaling states. In fact, achieving the ultimate limit of optical communication capacity, especially in the low light regime, requires coherent joint detection of multiple pulses. Despite their superiority, such joint detection receivers are not in widespread use because of the difficulty of constructing them in the optical domain. In this work we describe how optomechanical transduction of phase information from coherent optical pulses to superconducting qubit states followed by the execution of trained short-depth variational quantum circuits can perform joint detection of communication codewords with error probabilities that surpass all classical, individual pulse detection receivers. Importantly, we utilize a model of optomechanical transduction that captures non-idealities such as thermal noise and loss in order to understand the transduction performance necessary to achieve a quantum advantage with such a scheme. We also execute the trained variational circuits on an IBM-Q device with the modeled transduced states as input to demonstrate that a quantum advantage is possible even with current levels of quantum computing hardware noise.

Development of an Affordable FPGA Board for Advancing Software-Defined Radio Research in Auchi Polytechnic

This paper detailed the design and development of an affordable software-defined radio (SDR) system tailored for academic environments at Auchi Polytechnic. The system integrated a moderately fast analog-to-digital converter (ADC), an audio digital-to-analog converter (DAC), and an off-the-shelf field-programmable gate array (FPGA) for digital signal processing. The primary objective was to enhance the teaching of fundamental engineering concepts related to communications. To demonstrate its capabilities, the system included hardware blocks for demodulating amplitude modulation (AM) and frequency modulation (FM) signals. This approach provided a cost-effective solution for advancing SDR research and education. The SDR paradigm, which replaces traditional hardware configurations with flexible software-based solutions, has revolutionized communication receivers. Incorporating SDR into undergraduate curricula has become increasingly valuable, offering students hands-on experience with cutting-edge technologies and skills relevant in both academic and industrial settings. While commercial SDR solutions such as the RTL-SDR dongle offer an accessible introduction to SDR concepts, they often fall short in providing a deep understanding of the underlying principles and design intricacies. To address this educational gap, the developed SDR platform aimed to offer practical experience and delve into the fundamental principles of SDR design, leveraging advancements in digital technologies like FPGAs and ADCs to create a cost-effective, educational SDR system.

Multiplier-less Broadband and Linear Phase Digital Hilbert Transformers

The Hilbert transformation for generating the analytic signal or signal envelope is widely used in modern communication receivers, in radar and sonar systems. It introduces a 90∘\\documentclass[12pt]{minimal} \\usepackage{amsmath} \\usepackage{wasysym} \\usepackage{amsfonts} \\usepackage{amssymb} \\usepackage{amsbsy} \\usepackage{mathrsfs} \\usepackage{upgreek} \\setlength{\\oddsidemargin}{-69pt} \\begin{document}$$90^{\\circ }$$\\end{document} phase shift of the input signal. Since the impulse response of the ideal Hilbert transformer is non-causal, it must be approximated by an FIR or IIR filter. This paper shows results of novel algorithms for designing broadband digital IIR Hilbert transformers and its implementation. The designs employ Galerkin or collocation techniques. The transfer function of the Hilbert transformer is a rational polynomial of low order and exhibits approximately linear phase. The filters match the 90∘\\documentclass[12pt]{minimal} \\usepackage{amsmath} \\usepackage{wasysym} \\usepackage{amsfonts} \\usepackage{amssymb} \\usepackage{amsbsy} \\usepackage{mathrsfs} \\usepackage{upgreek} \\setlength{\\oddsidemargin}{-69pt} \\begin{document}$$90^{\\circ }$$\\end{document} phase shift requirement of Hilbert transformers almost perfectly and exhibit approximately constant group delay in the passband. The achieved image rejection ratio is typically larger than 50 dB. The quantization of the filter coefficients is realized by a Canonical Signed Digit (CSD) representation, reducing the hardware resources compared with two’s complement. The resulting filters are multiplier-less, which is crucial for high-speed signal processing and low power consumption. The design techniques and the CSD representation are realized in a MATLAB toolbox. The filters were moreover implemented in VHDL and SystemC. Additionally, a MATLAB tool for automatically generating a VHDL package containing the filter parameters has been implemented.

Performance analysis and testing of LYSO-SiPM X-ray communication receiver

This paper introduces the characteristics of the LYSO-SiPM-based receiver used in X-ray communication (XCOM). The X-ray signal receiving scheme based on a scintillator and photodetector is an important part of the XCOM system. However, the inherent characteristics of the scintillator and photodetector hinder the improvement of the performance of the X-ray signal receiver. Thus, this paper proposes a comprehensive analysis model for modeling the counting statistical characteristics of the LYSO-SiPM-based receiver, and analyzes the effects of the receiver's characteristics on the communication performance of the OOK-modulated XCOM system. Furthermore, the LYSO-SiPM pulse X-ray signal receiver is optimized, and its performance in the XCOM experiment is tested. The experimental results are consistent with the theoretical analysis trend, indicating that the proposed analytical model can be used for XCOM performance analysis and optimization.