Communication Receiver Research Articles

A Bandwidth Efficient Dual-Function Radar Communication System Based on a MIMO Radar Using OFDM Waveforms

A novel dual-function radar communication (DFRC) system is proposed, that achieves high communication rate, and can flexibly trade-off rate for improved sensing performance. The proposed system is a monostatic multiple-input multiple-output (MIMO) radar and transmits wideband, precoded, orthogonal frequency division multiplexing (OFDM) waveforms from its antennas. The system subcarriers are divided into two groups, i.e., shared and private. On a shared subcarrier, all antennas can transmit simultaneously, while on a private one only one antenna can transmit at a time. A novel target estimation approach with low complexity is proposed to overcome the coupling of transmitted symbols and radar target parameters in the target echoes, which arises due to the shared use of subcarriers by the transmit antennas. The proposed method first operates on all (shared and private) subcarriers to obtain coarse angle estimates, and then fine-tunes those estimates based on the signal received on the private subcarriers. The resolution of the coarse angle estimates is limited by the physical receive array, while the fine-tuning is enabled by effectively constructing a virtual array that has larger aperture than the receive array. The precoding matrix is optimally designed to optimize a weighted combination of the beampattern error with respect to a desirable beampattern, and the signal-to-noise ratio at the communication receiver.

A K-Band Hybrid-Packaged Temperature-Compensated Phased-Array Receiver and Integrated Antenna Array

This article presents an eight-channel 1.9-dB noise figure (NF) <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">$K$ </tex-math></inline-formula> -band phased-array receiver (RX) for satellite communication (SATCOM). It employs the hybrid-packaged 65-nm CMOS beamformer and 0.1- <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">$\mu \text{m}$ </tex-math></inline-formula> GaAs low-noise amplifiers (LNAs) based on the fan-out wafer-level chip-scale packaging (WLCSP) technology. For the power-efficient RX implementation, the power consumption of gain and phase tuning blocks is discussed, and the fully passive phase shifter (PS) and attenuator (ATT) are employed in this work. A global biasing scheme is proposed to ensure performance uniformity across temperature variations. Across the SATCOM band of 17.7–20.2 GHz, the proposed hybrid-packaged phased-array RX IC only consumes 30.2-mW dc power per channel and achieves < 1.2-dB gain variation and < 0.9-dB NF variation from −40° to 85 °C. Based on the RX IC, a dual-polarized 1024-element RX antenna array is further introduced. The measured gain-to-noise temperature ratios (G/Ts) are 6.22 and 6.51 dB/K at 19.7 GHz for left- and right-hand circular polarizations, respectively.

A blind receiver for OFDM communications

A blind receiver for OFDM communications

CMOS Platform for Everyday Applications Using Submillimeter Electromagnetic Waves

CMOS (Complementary Metal Oxide Silicon) integrated circuits (ICs) technology is emerging as a means for realization of capable and affordable systems that operate at frequencies near 300GHz and higher. This is lowering a key barrier for utilizing the sub-millimeter electromagnetic waves in everyday applications. Despite the fact that the unity maximum available gain frequency, fmax of NMOS transistors (with connections to the tope metal layer) has peaked at 320 GHz, signal generation up to 1.33 THz, coherent detection up to 1.2 THz and incoherent detection up to 10 THz have been demonstrated using CMOS integrated circuits. Furthermore, highly integrated rotational spectroscopy transceivers operating at frequencies up to near 300 GHz, 300-GHz and 400-GHz concurrent transceiver pixels and arrays for high resolution radar imaging, and 300-GHz and 390-GHz transmitters, and 300-GHz receivers for high data-rate communication have been demonstrated in CMOS. The performances of these CMOS circuits are sufficient or close to being sufficient to support electronic smelling using rotational spectroscopy that can detect and quantify concentrations of a wide variety of gases; imaging that can enable operation in a wide range of visually impaired conditions; and high-bandwidth communication. Lastly, techniques for affordable packaging and testing sub-millimeter wave systems are suggested based on experimental demonstrations.

A blind receiver for OFDM communications

A blind receiver for OFDM communications

The Design of a Transimpedance Amplifier [The Analog Mind

High-speed transimpedance amplifiers (TIAs) serve in the front end of optical communication receivers (RXs). Despite or because of their simple topologies, TIAs pose rigid tradeoffs among their gain, noise, and bandwidth (BW).

Optimizing the Photodetector/Analog Front-End Interface in Optical Communication Receivers

Optimizing the Photodetector/Analog Front-End Interface in Optical Communication Receivers

Combined Radar and Communications With Phase-Modulated Frequency Permutations

This paper focuses on the combined radar and communications problem and conducts a thorough analytical investigation on the effect of phase and frequency change on the communication and sensing functionality. First, we consider the classical stepped frequency radar waveform and modulate data using M-ary phase shift keying (MPSK). Two important analytical tools in radar waveform design, namely the ambiguity function (AF) and the Fisher information matrix (FIM) are derived, based on which, we make the important conclusion that MPSK modulation has a negligible effect on radar local accuracy. Next, we extend the analysis to incorporate frequency permutations and propose a new signalling scheme in which the mapping between incoming data and waveforms is performed based on an efficient combinatorial transform called the Lehmer code. We also provide an efficient communications receiver based on a modified Hungarian algorithm. From the communications perspective, we consider the optimal maximum likelihood (ML) detector and derive the union bound and nearest neighbour approximation on the block error probability. From the radar sensing perspective, we discuss the broader structure of the waveform based on the AF derivation and quantify the radar local accuracy based on the FIM. Extensive numerical examples are provided to illustrate the accuracy of our results.

Low Power Analog Processing for Ultra-High-Speed Receivers With RF Correlation

Ultra-high-speed data communication receivers (Rxs) conventionally require analog digital converters (ADC)s with high sampling rates which have design challenges in terms of adequate resolution and power. This leads to ultra-high-speed Rxs utilising expensive and bulky high-speed oscilloscopes which are extremely inefficient for demodulation, in terms of power and size. Designing energy-efficient mixed-signal and baseband units for ultra-high-speed Rxs requires a paradigm approach detailed in this paper that circumvents the use of power-hungry ADCs by employing low-power analog processing. The low-power analog Rx employs direct-demodulation with RF correlation using low-power comparators. The Rx is able to support multiple modulations with highest modulation of 16-QAM reported so far for direct-demodulation with RF correlation. Simulations using Matlab, Simulink R2020a® indicate sufficient symbol-error rate (SER) performance at a symbol rate of 8 GS/s for the 71 GHz Urban Micro Cell and 140 GHz indoor channels. Power analysis undertaken with current analog, hybrid and digital beamforming approaches requiring ADCs indicates considerable power savings. This novel approach can be adopted for ultra-high-speed Rxs envisaged for beyond fifth generation (B5G)/sixth generation (6G)/ terahertz (THz) communication without the power-hungry ADCs, leading to low-power integrated design solutions.

Adaptive Digital Compensation of Analog Impairments in Frequency Interleaved ADC for Next-Generation High-Speed Communication Receivers

Adaptive Digital Compensation of Analog Impairments in Frequency Interleaved ADC for Next-Generation High-Speed Communication Receivers

Classifying wireless signal modulation sorting using convolutional neural network

Deep learning has recently been used for this issue with superior results in automatic modulation classification. Previous studies state that it is challenging to categorize a variety of modulation formats using traditional approaches; however, modulation classification is a crucial component of non-cooperative communication in wireless communication. The deep learning network was applied to solve the issue and get decent outcomes. This work uses a deep learning convolutional neural network (DLCNN) to classify three analog and eight digital modulation techniques by generating channel-impaired and synthetic waveforms as training data. The obtained DLCNN is tested by over-the-air indicators and a Software Define Radio(SDR) platform. The trained DLCNN estimates the modulation kind of each frame by taking 1024 samples of channel-impaired signals. The method includes generating several frames of 4-arry pulse amplitude modulation (PAM4) that are impaired with sampling time drift, Additive white Gaussian noise (AWGN), center frequency, and Rician multipath fading. The DLCNN predicts real inputs when receiving a signal with complex samples of baseband. Before updating the network coefficients and on all iterations, the data store transforms data from files and records it. This network takes about 50 minutes to train using in-memory data and 110 minutes to train using disk data. The evaluation of the trained DLCNN is carried out by obtaining the classification accuracy for the test frames. The obtained outcome demonstrates that the developed network can achieve an accuracy of about 94.3 % in roughly 12 epochs for such types of waveforms, which elapsed about 26 minutes for training. This will increase the efficiency of spectrum usage and detect the modulation type of the wireless communication receivers

Top-Illuminated Avalanche Photodiodes With Cascaded Multiplication Layers for High-Speed and Wide Dynamic Range Performance

In this work, a novel top-illuminated avalanche photodiode (APD) with a In <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">0.52</sub> Al <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">0.48</sub> As multiplication (M-) layer is demonstrated. The cascaded M-layer design combined with the unique p-side up mesa structure allows relaxation of the fundamental trade-off between the gain-bandwidth product and the dark current. This leads to the simultaneous high-responsivity, high-speed, high-saturation-power, and low-dark current characteristics of our APDs. At around 0.9 V <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">br</sub> operation, the demonstrated device with its simple top-illuminated structure and large active window (mesa) diameter of 14 (24) μm exhibits a high responsivity (2.23 A/W), wide optical-to-electrical bandwidth (30 GHz), large gain-bandwidth product (270 GHz), low dark current (∼200 nA), and a saturation current as high as 11 mA. The excellent performance of this APD structure opens up new possibilities to further enhance the sensitivity performance of receivers for coherent communications or 106 Gbit/sec PAM-4 applications.

Directional modulation based on dual-function radar-communication system

Dual-function radar-communication (DFRC) system has recently been proposed to enable the co-design of radar and wireless communications, which in turn alleviates the increased spectrum congestion crisis. DFRC system exploits the transmit beamforming technique and waveform diversity, the combination of which enables the system to embed information in radar emission. In this paper, directional modulation (DM) based on dual-function radar communication system is proposed. To achieve the security of information transmission, a beam weight vector set is established. The reference beam weight vector is initially designed and the remaining weight vectors are derived from it, by minimizing the differences between them. The transmitting beams shaped by the designed weight vectors are almost the same in radar main lobe, but differ in the amplitudes and phases towards the direction of intended communication receivers. The communication receivers decode the data based on its radiated beam. The proposed communication process is secure against intercept from directions other than the pre-assigned communication directions. Simulation results are provided for performance evaluation and to demonstrate the effectiveness of the proposed scheme.

Wissenschaftskommunikation in Leichter Sprache? Eine Bestandsaufnahme der Verwendung von Leichte-Sprache-Angeboten in den Webauftritten deutscher Forschungs- institutionen und Hochschulen

Recent research on the impact and reception of science communication pointed out, that marginalized groups in society like people with mental or learning disabilities or people with limited language skills often remain unconsidered by conventional measures of communicating scientific content (Humm/Schrögel/Leßmöllmann 2020). Easy reading concepts might be a helpful approach to a more inclusive mode of science communication. The paper evaluates if German science institutions and universities offer easy reading versions on their websites to enable the above-mentioned groups to access fundamental scientific information. In a second step it analyses how these easy reading versions have been formally implemented and to what extent the requirements of the Federal Ordinance on Accessible Information Technology (BITV 2.0) have been followed. The paper aims to give a first overview on the efforts of scientific institutions to address marginalized groups and to point out deficits of these efforts.&#x0D;

Long‐Range Optical Wireless Communication System Based on a Large‐Area, Q‐Dots Fluorescent Antenna

AbstractFluorescent concentrators (FCs) have been recently proposed as optical condensers for visible light communications (VLC) and optical wireless communication (OWC) receivers, with advantages over conventional optical stages in terms of optical gain and field of view (FoV). However, the use of FC‐based receivers in real‐world scenarios is hampered by the need for large resilience of the involved chromophores to sunlight exposure, and availability of large‐area FC substrates with suitable optochemical properties. This paper presents an innovative OWC system, based on a high‐power blue LED and a large‐area FC‐based on CuInS2 quantum dots (Q‐Dots) as receiving optical stage. A thorough characterization of the FC material in terms of conversion efficiency, temporal response, and FoV is provided, along with a full set of outdoor measurements. The combination of the Q‐Dots fluorophores chemico‐physical properties with the strong DC rejection granted by the design receiver stage allows error‐free VLC link distances up to 60 m and baud rates up to 1 Mb/s. This work represents the first demonstration of long‐range VLC links under strong solar irradiance using large‐area FC antennas and paves the way to deployment of long‐range free‐space optical links with minimal susceptibility to misalignments and pointing instabilities between receiver and transmitter.

Analysis of Audience Reception Against Intercultural Communication Represented in the Film Bumi Manusia

Bumi Manusia is a film by Pramoedya Ananta Toer which has a theme about the love story of a young man of Javanese descent with a girl of Dutch descent and his struggles in the midst of the early 20th century Indonesian movement. audience, how to interpret the message received from a media, namely from a film which is one of the mass communication media. The purpose of this study is to find out how the audience's reception of intercultural communication in the film Bumi Manusia. This research is a descriptive analytical research method using Stuart Hall reception analysis with the concept of encoding-decoding and data collection techniques using the interview method. This study succeeded in showing different audience receptions in interpreting intercultural communication in the film Bumi Manusia. The results of this study indicate, the audience perceives into three types of dominant hegemonic, negotiated reading and optional reading. Viewers who are included in this dominant hegemonic classification understand the message content as it is. Audiences who are in a negotiating position receive texts or scenes of intercultural communication in the film but are not fully accepted because there are still things to negotiate. While the audience is in an oppotional position, the audience does not accept the text or scenes of intercultural communication presented in the film.

5G ДВУХДИАПАЗОННАЯ ПРЯМОУГОЛЬНАЯ МИКРОПОЛОСКОВАЯ АНТЕННА С ДВУМЯ ТРАВЛЕНИЯМИ И ВЕРХНИМ ШЕСТИГРАННЫМ ВЫРЕЗОМ НА КОНЦЕ CPW FED

Around the world, wireless or distant communication has become fundamental and indispensable.Every day, billions of users access calls, the internet, and social media. Many electricalequipment, including the antenna, are used in the sophisticated networks and systems that supportthat massive information interchange. An electrical device known as an antenna sends or receivesinformation across space. The antenna is a key component in many systems, including radio andtelevision transmission, communications receivers, radar, cellular phones, Bluetooth-enabledgadgets, and satellite communications. The rapid expansion of wireless technology and personalcommunication has increased the demand for multiband antennas, which can operate at severalfrequencies and are suited for a variety of applications. Dual-band coplanar waveguide (CPW)fed rectangular microstrip patch antenna for 5G, WiMAX band, ISM Band, and WLAN applicationsis presented in this paper. The proposed antenna is robust, cheap, light weight, and easy tofabricate, resonating at 2.4 GHz in -12.182379 s11 with 205.7 MHz BW and 3.42 GHzin -37.344879 s11 with 464.9 MHz BW whereas gain is 3.85 and 3.41 respectively. Patch elementsare placed on isolation FR408 (loss-free) substrate of relative permittivity 3.75 kept at a substrateheight of 1.6 mm. Results of simulation are presented using CST STUDIO SUITE 2019.

Chip-Level GHz Capable Balanced Quantum Homodyne Receivers

We present a design of balanced homodyne receivers suitable for ultra-low noise quantum applications such as continuous-variable quantum key distribution and quantum random number generation. For best noise and bandwidth performance a die-level low-parasitic photodiode together with a low-noise high-speed transimpedance amplifier are explored together with a planar lightwave circuit splitter chip serving as a photomixer. Bandwidths of 750 MHz and 2.6 GHz were accomplished while maintaining optimum noise performance, as evidenced by very high quantum-to-classical noise ratios of 26.8 and 18.6 dB, respectively. A common-mode rejection ratio of at least 40 dB was achieved for a frequency range of up to 1 GHz. Its application for continuous-variable quantum key distribution was evaluated by means of estimations under a strict untrusted receiver assumption, showing its potential for generating up to 43 Mbit/s secure-key rate over a reach of 10 km, whereas up to 100 Mbit/s could be supported at shorter reaches. Moreover, the high quantum-to-classical clearance values can enable high quality quantum random number generation at Gb/s rates. The multi-purpose operation of the designed balanced receivers for classical communications was examined showing reception sensitivities of −55.8 and −52.6 dBm at 500 Mbit/s and 1 Gbit/s quadrature phase shift keying transmission, respectively, using the 750 MHz receiver. The faster 2.6 GHz receiver enabled 10 Gbit/s duobinary transmission at −14.8 dBm sensitivity.

Problems and prospects of digitalization of agriculture in the Republic of Tyva

The problems and prospects of development of digital technologies in the agricultural sector of the Tyva Republic were studied. The use of digital technology remains extremely low in Tyva. The region significantly lags behind Russia as a whole and the Siberian Federal District in the development of digitalization processes. Challenges hindering the development of the information society in the Republic of Tyva are the presence of hard-to-reach settlements with complex geographical features; infrastructure restrictions in terms of registration (approval) of necessary documents and interaction with network organizations in the conclusion of contracts for technological connection to the power grid; lack of coverage and uncertain reception of mobile radio telephone communications in remote rural settlements of the Tyva Republic; lack of qualified specialists in information and telecommunication technologies, poor development of scientific and innovation potential; low skills in using information technologies; import dependence on imported software, technologies and equipment; digital inequality between municipalities. To improve the efficiency of agriculture in the region, it is necessary to introduce digital technologies into agricultural production: collecting data on sown areas and pastures, making digital maps of agricultural land, using remote-controlled sensors to monitor the quality of crops, the movement of agricultural vehicles and animals, etc. The use of digital technologies will promote the products of agricultural producers to the consumer, which will expand access to financial resources and markets due to the coordinated action of all parts of agricultural production. The main directions of digitalization of the industry were outlined and promising digital technologies for application in the agricultural sector of the Tyva Republic were specified.

Energy Modeling Based on Power Profiling of Wireless Sensor Device

This article elaborates on an accurate energy model (EM) for wireless sensor devices (WSDs) based on power consumption measurement. A deep understanding of WSD’s energy cost depends on the WSD’s functional components contributing to the wireless communication process. The model includes different stages of transmission (Tx) and reception (Rx) communication modes. The practical EM is developed with data packet lengths, data rate, operation status, predesigned stages versus appropriate communication bus, and power mode, including mutual data transfers between the microcontroller and the radio module. The validity of the EM is verified through an experimental setup having a TelosB device. As expected, the modeled and measured energy consumed by the WSD operating from 1-to-4-MHz CPU frequencies and the 2-to-100-byte payload is in very good agreement. It was found that, compared to the energy consumption in processing, Tx, listening, and Rx phases, the data transfer consumes up to 40% of total WSD energy, whereas this aspect is often neglected in usual models. Overall, the proposed model provides significant accuracy and might be helpful in improving the energy efficiency of future wireless sensor networks.