Communication Receiver Research Articles

A 0.71-mW Antenna-Coupled On–Off-Key Receiver for Gbps Millimeter-Wave Wireless Communications

This article presents a 39-GHz 800-Mb/s antenna-coupled ON–OFF-key (OOK) receiver with a baseband output capable of driving a 50- <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">$\Omega $ </tex-math></inline-formula> load. The antenna-coupled receiver demonstrates a bit error rate (BER) of <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">$10^{-3}$ </tex-math></inline-formula> over a range of 18 cm while dissipating only 0.71 mW for a record energy efficiency per distance metric of 0.049 pJ/bit/cm. A wireline version of the receiver achieves a record sensitivity level of −36 dBm without preamplification while dissipating only 1.15 mW, resulting in an energy efficiency of 1.44 pJ/bit at a BER of <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">$10^{-3}$ </tex-math></inline-formula> . Including 11.5 dB of RF gain prior to the wireline receiver, 800-Mb/s communication is demonstrated at 3.67 m for a BER of <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">$10^{-5}$ </tex-math></inline-formula> . The low power consumption and long range make this receiver suitable for scaling to hundreds or thousands of elements in massive multi-in–multi-output (MIMO) arrays for next-generation millimeter-wave wireless communications systems.

Deep Learning for Waveform Level Receiver Design With Natural Redundancy

High-speed information transmission system demands more powerful communication receivers. In this paper, we integrate deep learning algorithms into constructing waveform level receiver, which is capable of harnessing natural redundancy (NR) in raw message sources. Owing to end-to-end learning paradigm of neural network (NN), the proposed NN receiver can accomplish joint symbol timing synchronization and demodulation based on oversampled waveform sequences directly. The prevalent bidirectional LSTM (BiLSTM) and Transformer structures, suitable for excavating sequential correlation of complex sources and waveform sequences, are considered as the backbone of NN receivers. Under the cases of clean label and noisy label, we conceive two novel training algorithms and interpret their principles in theory. The clean label bits are accessible from original source encoding schemes, while noisy label bits are available from the decision results of canonical receivers with independently noised waveform sequences. When noisy labels possess sufficiently small error rates, optimized NN receiver is competitive with that adopting the accurate labels. As for Markov sources and natural language text sources, simulation results show that the proposed NN receivers’ performances are superior to the classical receivers without a priori knowledge, especially when high spectral efficiency modulation schemes are encountered and random noise is significant.

Metalens integrated receiver to reduce the effect of angle of arrival jitter in free space optical communication

In this paper, we propose a metalens integrated receiver for free space optical communication, which provides robust performance in the presence of angle of arrival fluctuations jitter. As a proof of concept, we show that our proposed receiver can tolerate up to a 2.5 mrad angle of arrival fluctuations with a detector radius of 20 µm before reaching a 3 dB power penalty. We design a meta unit cell to realize the optimized phase profile and present a quasi-3D full wave simulation of the proposed architecture. The system shows steady signal power and bit error rate in the presence of angle of arrival fluctuation.

A Signal processing method of OFDM communication receiver based on CNN

Orthogonal frequency division multiplexing (OFDM) the signal processing is a key issue in wireless communication research. The multipath effect and Doppler shift of wireless communication channels can lead to distortion of the transmitted signal, which poses a considerable challenge to the information recovery of communication receivers. This paper presents the signal processing method of OFDM communication based on convolutional neural network (CNN). The method replaces all signal processing modules of the OFDM communication receiver with CNN, and the information is recovered by the CNN. In order to adapt to the processing of communication signals, we designed a one-dimensional convolutional neural network (1D-CONV-CNN) model as the neural network structures by this method. Simulation results indicate that the signal processing method effectively reduces the bit error rate (BER) and improves its performance compared with the conventional reception method under different channel conditions.

Doing More with Ambient Light: Harvesting Indoor Energy and Data Using Emerging Solar Cells

On one side, the capacity of the world’s photovoltaic (PV) systems is experiencing unprecedented growth; on the other side, the number of connected devices is rapidly increasing due to the development of advanced communication technologies. These fields are not completely independent, and recent studies show that indoor energy harvesting is a great candidate for answering the energy challenges of future generations of telecommunications, namely 5G and 6G, ideal for internet-of-things (IoT) scenarios, i.e., smart homes, smart cities, and smart factories. The emerging PV technologies have shown amazing capabilities for indoor energy harvesting, displaying high power conversion efficiency, good flexibility, and champion-specific powers. Recently, the excellent dynamic performance of PV devices enabled them to be used as data receivers in optical wireless communication (OWC) scenarios, calling forth an innovative system able to simultaneously harvest energy and receive communication data with a single PV device. This article reviews the recent literature devoted to the exploitation of photovoltaic technologies for simultaneous indoor energy harvesting and OWC data reception. This contribution highlights the strong potential of the approach toward the next generation of Green IoT systems and the current challenges that need to be addressed with regard to the physics of solar cells, from laboratory to large-scale applications.

Target parameter estimation for OTFS radar using sparse signal processing

In this paper, we consider a monostatic radar receiver for a joint communication and radar (JCR) system that transmits orthogonal time frequency space (OTFS) frames for target detection and parameter estimation. The circular prolate pulse shape (CPPS) is employed over the OTFS signal as it has lower out-of-band (OoB) power radiation in comparison with the rectangular pulse shaped (RPS) OTFS. The PAPR of CPPS OTFS signal shows lowest value for larger frame duration and hence the signal can be considered to be a good candidate for JCR system. In the Delay-Doppler (DD) domain, the radar channel is sparse and therefore, we model the target detection problem as a sparse recovery problem to generate target profiles with higher peak-to-sidelobe ratio (PSLR). The target detection is carried out in the DD domain, the time–frequency (TF) domain, and in the time domain (TD). Sparse signal recovery algorithms like the orthogonal matching pursuit (OMP) algorithm, the subspace pursuit (SP) algorithm, and the sparse Bayesian learning (SBL) based algorithm are used in target parameter estimation. The performance of these algorithms are compared in terms of their computational complexity, the root mean squared error (RMSE) in the estimates of range and velocity and PSLR value in the target profiles. Simulation results validate that the proposed CPPS OTFS based radar system could detect the targets accurately in all the three domains and produce target profiles with almost zero side lobes.

A “careful study” on public opinion. An exemplary investigation of media monitoring through press clippings collections in the League of Nations’ Information and Mandates Sections

This article seeks to shed some light on institutional monitoring practices employed by the League of Nations during the 1930s. It explores internal reception of external communication on the organisation and its work and asks (and partially answers) what processes and practices were established by the organisation concerning media monitoring and which views and interpretations these practices (re-)produced. For that purpose, it discusses findings from four exemplary hermeneutic case studies conducted on collections of a total of 701 press clippings collected and curated by League organs. To provide a topical focus (and, simultaneously, increase the transdisciplinary value of the presented research) all four collections concern the League of Nations’ project of international control over colonial policy and are accordingly sourced from the archival section files of the organisation’s Mandates Section. The article contextualises the findings concerning the clippings with information derived from the minutes and reports of the League’s experts’ commission on Mandates, the Permanent Mandates Commission.

Wake-Up Receiver for Underwater Acoustic Communication Using in Shallow Water.

A data frame transmitted over the underwater acoustic channel usually begins with a preamble. Therefore, underwater communication systems have a dedicated receiver that constantly listens to the preamble signals. A receiver that is to work effectively in shallow waters must have solutions that effectively reduce the impact of the permanently occurring multipath propagation. The article presents a solution based on complementary broadband signals. Initial tests were carried out using the Watermark simulator to determine its reliability in such a difficult propagation environment. The results of experimental tests carried out in a model pool are also included. Details of the implementation of the wake-up receiver are presented.

A simplified mode diversity coherent receiver based on non-mode-selective photonic lantern and Kramers-Kronig detection

This paper proposes a mode-diversity space optical communication receiver for long-range space optical communication, which can compensate for the effect of atmospheric turbulence and be applied between 2 km and 16 km space optical communication with a low-cost, low-power and low-complexity feature. The receiver uses a non-mode selective photonic lantern as a mode demultiplexer, merging using an equal gain combining (EGC) algorithm and a Kramers-Kronig (KK) detection technique to accomplish the optical detection of high-dimensional modulated format signals. The performance of the receiver under different turbulent conditions is experimentally investigated, showing significant compensation for atmospheric turbulence. The experimental results show that the proposed scheme achieves a gain of 4–5 dB at BER = 3 × 10−3 compared to a single-mode fiber (SMF) receiver under moderately strong turbulent conditions.

Remote Phase-Shift LiDAR With Communication

The integrated sensing and communication is emerging as a crucial technology due to reduced hardware costs and broad application scenarios. However, there is a contradiction between ranging and communication in phase-shift light detection and ranging (LiDAR) for the utilization of the subcarrier’s phase. A scheme called phase-shift laser ranging with communication (PLRC) is proposed to enable both ranging and communication using the same transmitted signal in this paper. The message encoded with pseudo-random noise code is modulated into the phase of the subcarrier for laser emission, and thus the received signal carries the data and the phase difference due to the distance. The received signal is subject to correlation, waveform recovery, and phase-shift measurement with the local signal at the LiDAR transceiver, and the distance is derived from the complete phase to avoid range ambiguity. The data is extracted from the spread spectrum signal at the communication receiver. The performance in terms of the measured distance and precision of LiDAR, the bit error rate of communication is obtained for the proposed solution. Meanwhile, the optimized light ratio for ranging and communication is derived. The experimental demonstration is carried out, the range precision is <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">$3.54\,\,{\times }\,\,10^{-3}$ </tex-math></inline-formula> m, and the communication capability meets 1.43 Mbit/s.

People lie less when they put on a medical face mask

The current study examined how a face mask people wore during the COVID-19 pandemic affects frequent lying and successful telling and detecting lies and truths in a face-to-face deception task. Participants were psychology students who acted as senders and receivers of true and false communications under three conditions: visible face, wearing a face mask, and blindfolding in addition to the face mask. Participants arrived in groups of eight. They first completed a lying questionnaire and then participated in the deception task. Their goal was to outperform the rest of the group to retain a bonus of additional course credit. Results indicated that participants reduced the number of lies told when wearing the face mask compared to chance expectancy (d = −.27) and visible face (d = −0.21).In addition, participants were more successful in detecting truths in the face mask condition than in the visible face condition (d = 0.21). Finally, self-assessed lie-telling ability predicted frequent lying in the face mask but not in the other conditions. It was suggested that participants wearing the face mask were affected by the attitudes and norms that prevailed during the COVID-19 pandemic, where consideration was required, and people were relatively thoughtful and kind. The face mask reminded participants of these norms and motivated participants to act accordingly.

Photonic super-resolution millimeter-wave joint radar-communication system using self-coherent detection.

A millimeter-wave (MMW) joint radar-communication (JRC) system with super-resolution is proposed and experimentally demonstrated, using optical heterodyne upconversion and self-coherent detection downconversion techniques. The point lies in the designed coherent dual-band constant envelope linear frequency modulation-orthogonal frequency division multiplexing (LFM-OFDM) signal with opposite phase modulation indexes for the JRC system. Then the self-coherent detection, as a simple and low-cost means, is accordingly facilitated for both de-chirping of MMW radar and frequency downconversion reception of MMW communication, which circumvents costly high-speed mixers along with MMW local oscillators and, more significantly, achieves the real-time decomposition of radar and communication information. Furthermore, a super-resolution radar range profile is realized through the coherent fusion processing of dual-band JRC signals. In experiments, a dual-band LFM-OFDM JRC signal centered at 54 GHz and 61 GHz is generated. The two bands feature an identical instantaneous bandwidth of 2 GHz and carry an OFDM signal of 1 Gbaud, which helps to achieve a 6-Gbit/s data rate for communication and a 1.76-cm range resolution for radar.

A Roadmap for Gigabit to Terabit Optical Wireless Communications Receivers.

Silicon photomultipliers' relatively large areas and ability to detect single photons make them attractive as receivers for optical wireless communications. In this paper, the relative importance of the non-linearity and width of SiPMs' fast output in their performance in receivers is investigated using Monte Carlo simulations. Using these results, the performances of receivers containing different SiPMs are estimated. This is followed by a discussion of the potential performances of arrays of existing SiPMs. Finally, the possible dramatic improvements in performance that could be achieved by using two stacked integrated circuits are highlighted.

Deep-Learning-Based Recovery of Frequency-Hopping Sequences for Anti-Jamming Applications

The frequency-hopping communication system has been widely used in anti-jamming communication due to its anti-interception and anti-jamming performance. With the increasingly complex electromagnetic environment, the frequency-hopping communication system needs more flexible frequency-hopping patterns to deal with interferences, which brings great challenges to the communication receiver. In this paper, an intelligent receiving scheme of frequency-hopping sequences is proposed, which combines time–frequency analysis with deep learning to realize an intelligent estimation of frequency-hopping sequences. A hybrid network module is designed by combining a convolutional neural network (CNN) with a gated recurrent unit (GRU). In the proposed network module, the combination of a residual network (ResNet) and squeeze and extraction (SE) improves the feature extraction and expression capabilities of the CNN network. The GRU network is proposed to solve the problem of dealing with signals with variant input lengths. A transfer learning scheme is further proposed to deal with communications systems with different frequency-hopping sets. Simulation results show that the proposed method has strong generalization ability and robustness, and the bit error rate (BER) performance of intelligent receiving is close to the receiving performance under ideal conditions.

Hardware Architecture of a QAM Receiver for Short-Range Optical Communications

Short-reach optical fiber communications systems aim to achieve high throughput, in the order of tens of Gbps. The implementation of these high-speed systems requires parallel processing, which makes low-complexity designs of their subsystems a key to the successful large-scale deployment of this technology. Half-Cycle Nyquist Subcarrier Modulation (HC-SCM) was originally suggested for these systems with the goal of using as much bandwidth as possible and, therefore, achieving high communication rates. Recently, Oversampled Subcarrier Modulation (OVS-SCM) was proposed as an alternative more computational efficient than HC-SCM and also with a better spectral efficiency. This paper proposes a hardware-efficient architecture for an OVS-SCM receiver, which takes into account the inherent parallel processing of these systems. This receiver takes 16 samples in parallel from a 5 GSa/s analog-to-digital converter with a 3.2 GHz 3 dB bandwidth. Design solutions for the frame detection block, the mixer, the resampler, the fractional interpolator, the matched filter and the timing estimator are presented. Our results show that, compared to the HC-SCM receiver, this proposal reduces the computational load of the downconverter stages by 90%. FPGA implementation results are given to demonstrate that our proposal can be implemented in state-of-the-art devices.

Базовые конструкции СВЧ балансных фильтров на оттекающих поверхностных акустических волнах

Ladder filters on leaky surface acoustic waves (LSAW) with electrical connection of resonators provide the lowest insertion loss IL=0.6-1.2 dB as compared with other types of LSAW filters, such as longitudinally coupled resonator filters. A drawback of ordinary nonsymmetrical ladder filters on LSAW is their limited selectivity (or minimal attenuation in the stop band) about UR=40-45 dB. In addition some problems arise when matching nonsymmetrical ladder filters to balanced or differential microcircuits. The present paper describes basic symmetric П-type and Т-type sections as well as various structures of ladder filters that allow to achieve a high selectivity thanks of parasitic electromagnetic signal (EMS) suppression. An extra advantage of balanced LSAW filters is their possibility to work with high impedance symmetric loads. The results of our study have been illustrated by few examples of balanced filters constructions on frequency 1217 MHz with selectivity UR=55-7- dB and low insertion loss IL=1,5-2,0 dB. Filters exhibiting high selectivity UR=55-70 dB and small insertion loss IL=1,2-4,0 dB. The described constructions may be used as basic for application on TV tuners, receivers of communication and navigation systems in frequency range 600-2000 MHz.

Fiber communication receiver models based on the multi-head attention mechanism

In this paper, an artificial-intelligence-based fiber communication receiver model is put forward. With the multi-head attention mechanism it contains, this model can extract crucial patterns and map the transmitted signals into the bit stream. Once appropriately trained, it can obtain the ability to restore the information from the signals whose transmission distances range from 0 to 100 km, signal-to-noise ratios range from 0 to 20 dB, modulation formats range from OOK to PAM4, and symbol rates range from 10 to 40 GBaud. The validity of the model is numerically demonstrated via MATLAB and Pytorch scenarios and compared with traditional communication receivers.

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