Simultaneous Reception Research Articles

Scalability Study of All-Photonics Metro/ Access Network With Simultaneous Reception of Wavelength-Multiplexed Control and Main Signals

Scalability Study of All-Photonics Metro/ Access Network With Simultaneous Reception of Wavelength-Multiplexed Control and Main Signals

Lu Xun’s Heteromodal Realism

Abstract This article posits modern Chinese realism as heteromodal, capable of encompassing many modes of narration from a plurality of literary movements. Heteromodality results from the heterochronic Chinese importation of Western literary history, the simultaneous reception of what were originally successive historical periods. The fountainhead of heteromodal Chinese realism is Lu Xun’s 1918 “Diary of a Madman,” one of the first modern vernacular Chinese short stories. Though Lu Xun has long been considered a foundational writer of realism in China, critics have complicated this designation by pointing out his modernist or symbolist proclivities. This article redefines Lu Xun’s realism by enlarging the scope of inquiry beyond “Diary” itself to scrutinize its main Russian intertexts: Nikolai Gogol’s 1835 story “Diary of a Madman” and Leonid Andreev’s 1904 novella Red Laugh. Examining the elements that Lu Xun’s story cannibalizes from Russian intertexts, which have themselves defied straightforward categorizations such as realism, the article intervenes in long-standing discussions about the nature of realism in modern China and, more broadly, in recent conversations about peripheral realism.

Multichannel signal transmission and reception using compact multichannel underwater communication devices: A unified theory and experimental results from different underwater media

Simultaneous transmission of multiple signals over the same bandwidth allows for optimal utilization of the limited bandwidth in underwater systems and networks. To avoid using multiple spatially separated single-channel projectors, one compact multichannel device can be used instead [E. Zhang, R. Rashid, A. Abdi, “Particle velocity underwater data communication: Physics, channels, system and experiments,” IEEE J. Oceanic Eng. (2023); E. Zhang, R. Rashid, A. Abdi, “Underwater communication experiments for transmitting multiple data streams using a vector acoustic MIMO system: OFDM and FSK modulations,” Proc. Oceans (2023)]. Simultaneous reception of multiple signals using one compact multichannel device is also feasible and improves the communication performance, without using several spatially separated single-channel hydrophones [R. Rashid, E. Zhang, A. Abdi, “On the performance of a new wireless communication compact multichannel underwater receiver using a sphere vector sensor,” IEEE Transactions on Vehicular Technology (2023); R. Rashid, E. Zhang, A. Abdi, “Underwater acoustic signal acquisition and sensing using a ring vector sensor communication receiver: Theory and experiments,” Sensors (2023)]. In this paper, we present various experimental results using a number of compact multichannel underwater devices in different setups, and demonstrate their usefulness for underwater communication. [Work supported in part by NSF, Grant IIP-1500123].

Vibrating Micro-Capsule as an Autonomous Device for in-situ Endoscopic Scan and Body Tissue Characterization

This work concerns the implementation of a diagnostic technique for the digestive system using a device designed based on a spherical vibrating capsule of 1 cm in diameter and autonomous by its onboard electronics. For local scanning, this device is also equipped with a network of high-frequency optimized sensors. Depending on the desired diagnosis, this device can adapt its electromechanical characteristics to the nature of the application in transmission and/or simultaneous reception. It is also designed for network configuration to provide a 3D mapping of the acoustic properties of the environment under investigation (biological tissues).

Advanced Intrusion Detection in Vehicular Networks: Empowering Security through Hybrid Off-loading Techniques and Enhanced Radial Bias Neural Network

Over the last several decades, the implementation of ITS has shown to be the most efficient and successful strategy for expanding the variety of current transportation networks. Vehicle-based offloading of data going to be essential for forthcoming networking innovations like D2D and 5G due to the substantial contribution it makes to efficiently using network capability while wasting minimal power. Information transmissions that would normally need a cellular network's infrastructure may instead be made using alternative networking mechanisms including Bluetooth, WiFi, and opportunistic communications. Data offloading has the ability to significantly increase the efficiency with which network resources are used. The offloading of data from vehicles has a considerable impact on the strain on cellular networks. It helps the network achieve higher throughput by facilitating the simultaneous reception of data by a large number of users. First, we must establish that the problem of Vehicular data offloading is an NP-hard target set selection (TSS) issue before we can even begin to characterize it. Using a combination of Hybrid PSO and GWO, TSS selects a small group of nodes to do the redundant data exchange (Particle Swarm Optimization with Gray Wolf Optimization). Collaboration between individuals and ISPs to identify effective aim sets may provide useful insights. If malicious users are present in the target group, they may slow down network activity by spoofing or by reducing the network's offloading capacity. It is possible that the whole network's performance would suffer as a direct result of these malicious users. In this study, we suggest a hybrid approach to communication for specifying the intended audience. We take use of the characteristics of opinion dynamics amongst users to get around the issue of overlapping community detection. Trust-based metrics inferred from users' activities are used to ensure the safety of the target set. In order to call 911, the suggested work additionally incorporates a method of sorting and classifying the offload limitations through Radial Bias Neural Network (RBNN). The following may be determined with the use of the proposed work's performance indicators: precision, entropy, and delay.

Design of a highly mode-selective photonic lantern for IM/DD MDM transmission

Recently mode multiplexers and demultiplexers (MMUX/MDEMUX) based on photonic lantern (PL) techniques for few-mode fiber transmission have attracted great interest. However, the design of PLs with high modal selectivity has become a great challenge for weakly-coupled mode-division-multiplexing (MDM) applications. In this paper, we propose a highly mode-selective PL-MMUX/MDEMUX design for intensity-modulation/direct-detection MDM transmission adopting each non-degenerate mode or each pair of degenerate modes as an independent channel. For the PL-MMUX, differential-phase injection (DPI) scheme is adopted for each pair of degenerate modes and a corresponding low-modal-crosstalk dissimilar core arrangement method is proposed considering the interleaving positive and negative phase characteristics of modal lobes of degenerate linearly-polarized (LP) modes, which achieve very high modal selectivity. For the PL-MDEMUX, simultaneous reception of degenerate modes is achieved by combining the optical power of both degenerated modes utilizing non-mode-selective PLs. Numerical simulations for a 6-LP-mode PL-MMUX/MDEMUX are performed. Results show that the PL-MMUX with DPI scheme and proposed cores distribution achieve much lower modal crosstalk than other cores distributions and the overall modal crosstalk of the PL-MMUX and MDEMUX in back-to-back case is lower than -20.63 dB over the C-band for all modes. The tolerance of our design to imperfect fabrication of differentiator or environmental impact are also discussed. The proposed DPI and dissimilar core arrangement method have high expansibility and provide a new way for the design of highly selective PLs and are beneficial to the practical applications of weakly-coupled MDM transmission systems and networks.

ФОРМИРОВАНИЕ СТРУКТУРНОЙ СХЕМЫ РАДИООБМЕНА С ПРИМЕНЕНИЕМ ПСП

The structure of the radio exchange demonstrates the interconnection pattern of the drones with the control center. To protect against unauthorized access to control and navigation channels it is necessary to hide such data and increase their noise immunity. The aim of the work is to use signals with a pseudorandom sequence and duplicate control and navigation blocks in the information channel of a small-scale aerial vehicle. Thus, at the beginning of the paper, a general structural diagram of radio communication between the unmanned aerial vehicle and the control center is presented. The model of 2-element antenna array consisting of two non-directional antenna elements is considered. On the basis of which it is possible to conclude about the signal arrival with a phase shift, taking into account which it is possible to determine the output signal of the array. An important factor is the synchronization and encryption of the signal. Data synchronization can be used by synchronous signal transmission between the drone and the control center. To reduce the probability of interception of the synchronous signal, the data packets containing it are transmitted in a pseudo-random sequence. Synchronization is achieved by using a micronavigation system through continuous radio transmissions from a ground source and simultaneous reception and recording of the signal on the drone. A one-time encryption or scrambler with a reversible symmetric transformation of the encoded information can be used as an encryption or scrambler. A random number generator is used to generate a sequence of random data, from which an array of key information tied to a specific period of use is created. The phase method can be used to process the signal. By measuring the phase shift with a phase detector, you can determine the location of the radio source with respect to the base normal. Measurements can be made with a digital receiving antenna array. Signal processing with digital receiving antenna array is performed by the diagramming device and the adaptive processor unit. As a result, all data using this approach is entered into the information block with the use of a pseudo-random coding change scheme, pseudo-random permutation of the navigation and control blocks.

Broadband Microwave Photonic Channelizer with 18 Channels Based on Acousto-Optic Frequency Shifter

A microwave photonic channelizer can achieve instantaneous reception of ultra-wideband signals and effectively avoid electronic bottleneck; therefore, it can be perfectly applied to a wideband radar system and electronic warfare. In channelization schemes based on an optical frequency comb (OFC), the number of comb lines usually depends on that of the sub-channels. In order to improve the utilization rate of the comb lines of OFC, we propose a scheme to shift the frequency of OFC by using an acousto-optic frequency shifter (AOFS), which can obtain three times the number of sub-channels of the comb lines of an OFC. In order to simplify the experiment, only a three-line OFC is used in the experiment. A three-line local oscillator (LO) OFC is frequency-shifted up and down by two AOFSs, and nine optical LO signals with different frequencies are obtained, thereby realizing the simultaneous reception of eighteen sub-channels. The proposed scheme enjoys a large number of sub-channels and minimal channel crosstalk. Experimental results demonstrate that a 9-GHz bandwidth RF signal covering 10–19 GHz is divided into 18 sub-channels with a sub-bandwidth of 500 MHz. The image rejection ratio of the sub-channels is about 23 dB, and the spurious-free dynamic range (SFDR) of the receiver can reach 98 dB·Hz2/3.

A System Optimization Scheme for Bias Correction of Polarimetric Phased-Array Radar

With the change in the spatial angle, the cross-polarization isolation (CPI) of polarimetric phased-array radar (PPAR) changes as well, destroying the estimation of the target polarization scattering matrix (PSM). To correct the bias in PPAR, this article comprehensively designs the transmitting antenna, receiving antenna, and signal waveform and proposes a bias correction method based on system optimization. First, for the transmitting antenna of PPAR, the second-order cone program (SOCP) model is proposed to optimize the weighting coefficient. With the SOCP-based beamforming method, not only beam pattern in any spatial angle can be achieved, but also arbitrary polarization state can be precisely configured. Then, for the wideband receiving signal with a certain beamwidth, an angle estimation method based on eigenvalue decomposition is proposed in this article, which can effectively cure the challenges introduced by the beamwidth and signal bandwidth. Subsequently, for the signal waveform, the phase code is designed to measure all the elements of PSM in simultaneous transmission and simultaneous reception (STSR) mode, which could eliminate the biases of the moving speed and the second-order cross-polarization error. Finally, this article compares with other methods based on differential reflectivity, and experiments show that the factors such as the spatial angle, array structure, antenna beamwidth, signal bandwidth, motion speed, and signal-to-noise ratio (SNR) have the least influence on the present method in this article.

Simultaneous reception of AMCC signals and QPSK signals by a single coherent receiver with DSP.

This paper investigates an auxiliary management and control channel (AMCC) signal extraction method using digital signal processing (DSP) blocks with 3-step moving averaging that allows a single coherent receiver to receive main signal and AMCC signal simultaneously. Receiver sensitivity characteristics versus the modulation index (MI) and average number of the proposed DSP blocks are elucidated. Based on the results, we discuss a policy for designing the parameters. Experiments apply the design policy to achieve receiver sensitivity of -41.8 dBm with both 25 Gbit/s QPSK main signal and 128 kbit/s AMCC signal; the main signal sensitivity penalty is just 0.2 dB.

RESEARCH OF THE SEA PASSENGER PORT INFRASTRUCTURE MODERNIZATION TO SOLVE THE PROBLEM OF FORECASTING DEVELOPMENT, TAKING INTO ACCOUNT THE INFLUENCE OF THE EXTERNAL ENVIRONMENT

The efficiency of operation and interaction of “sea ferry/cruise company-sea passenger port-land transport infrastructure” systems directly depends on the dynamic influence of the external environment, which today determines the transition from deterministic models of decision-making to probabilistic ones. These changes on the basis of current trends in the industry in the form of the introduction of large cruise and ferry ships create the need to form a decision- making system for the reasonable modernization of infrastructure for the heads of ports and terminals. It is necessary to systematically modernize both the berthing infrastructure and change the internal processes of passenger handling in the terminal. The problems of forecasting the development of seaports in connection with the gradual recovery of passenger traffic, caused by a long period of restrictions due to COVID-19, are considered in the paper, as the first priority is the resumption of the route networks of the sea regions, which provide local passenger mobility. Based on the investigated models of ports and terminals evolution (Anyport model, Three Generations model, Workport model) it is revealed that today it is necessary to evaluate possible predictive scenarios of port development. The necessity of having the tools allowing to operatively analyze the situation in the sphere of sea ferry transportation and to model the scenarios of port congestion has been revealed and proved. The approach to estimate the variants of berths loading at simultaneous call of several big cruise vessels on the basis of models of mass service systems for subsequent estimation of infrastructure is considered in the paper. The object of the research is the Baltic Sea region and existing routes of cruise and ferry lines. A new theoretical partitioning of the region and sea passenger ports into four sections is proposed. The systematic analysis of all existing cruise and ferry line routes in each area has been carried out; data on cruise and ferry ship size, passenger capacity, average ticket price, and distance between terminals on the route have been presented. On the basis of the formed approach a new digital dynamic route map that allows both to investigate the current state of the route network and to estimate the possible changes is built. On the basis of the received data it is proved that the best development of passenger sea ports and terminals infrastructure is observed in the segment between the countries of Russia-Estonia-Finland-Sweden. Presented sea terminals have successfully realized the possibility of simultaneous reception of two big cruise vessels and modernized infrastructure during the period of restrictions on the reason of COVID-19, which corresponds to the formation of new points of growth in the Baltic Sea region, taking into account recovery of route networks. The generated big data on route networks accurately define the current state in the sphere of sea ferry/cruise transportation and they should be used in new digital simulation transport models when modeling different variants of sea passenger port operation, both at the stage of short-term planning and when solving the group of questions of development forecasting, which is especially relevant in the situation of competition between terminals for passenger traffic.

Volume and surface coil simultaneous reception (VSSR) method for intensity inhomogeneity correction in MRI.

Addressing intensity inhomogeneity is critical in magnetic resonance imaging (MRI) because associated errors can adversely affect post-processing and quantitative analysis of images (i.e., segmentation, registration, etc.), as well as the accuracy of clinical diagnosis. Although several prior methods have been proposed to eliminate or correct intensity inhomogeneity, some significant disadvantages have remained, including alteration of tissue contrast, poor reliability and robustness of algorithms, and prolonged acquisition time. In this study, we propose an intensity inhomogeneity correction method based on volume and surface coils simultaneous reception (VSSR). The VSSR method comprises of two major steps: 1) simultaneous image acquisition from both volume and surface coils and 2) denoising of volume coil images and polynomial surface fitting of bias field. Extensive in vivo experiments were performed considering various anatomical structures, acquisition sequences, imaging resolutions, and orientations. In terms of correction performance, the proposed VSSR method was comparatively evaluated against several popular methods, including multiplicative intrinsic component optimization and improved nonparametric nonuniform intensity normalization bias correction methods. Experimental results show that VSSR is more robust and reliable and does not require prolonged acquisition time with the volume coil. The VSSR may be considered suitable for general implementation.

On the effect of S-parameter stability of antenna and coupler on electrical balance duplexing

Electrical Balance Duplexers (EBDs) provide transmit-receive isolation to implement a form of self-interference cancellation to facilitate simultaneous transmission and reception from a single antenna in systems like In-Band Full-duplex (IBFD) transceivers. EBD works by coupling transmitter, receiver, antenna, and balancing impedance using a hybrid coupler. In recent pieces of literature, antenna impedance variations are considered the main factor limiting the EBD isolation bandwidth, while the EBD balancing impedance needs to be equal as much as possible to the antenna impedance to achieve high isolation. But hybrid couplers are also not ideal elements, and their S-parameters are not stable in the frequency domain. In this work, five broadband RF devices (two antennas, two couplers, and a 50-Ohm RF-load) are used to form four EBD set-ups. One of the antennas, designed by the authors, has more impedance stability in the frequency domain than the other one, which is a commercial antenna. Also, one of the couplers, designed by the authors, has more S-parameter stability in Ultra-Wideband (UWB) frequency domain than the other one, which is a commercial UWB coupler. The implemented EBDs show that when both antenna and coupler have strong S-parameter stabilities in the frequency domain, wider isolation bandwidth (UWB 1.5–3.5 GHz range) and higher EBD isolation are obtained.

A Successive Interference Cancellation-based Receiver for Secondary Surveillance Radar

Secondary Surveillance Radar communications, which purpose is to acquire aircrafts critical information, are on the brink of spectrum saturation. This is the result of dense traffic and different waveforms modulation schemes, used in Modes A/C and Mode S communication layers which share the same unscheduled propagation bandwidth. This leads to a significant rise of packet collision probability. In this context, we propose an original single-channel receiver able to process the simultaneous reception of several Mode A/C and S packets. The decoding strategy relies on the successive interference cancellation principle, comprising original detection, decoding and reconstruction processes. The relevance of our proposition is validated by numerical simulation and confirmed through field experiments on Automatic Dependent Surveillance-Broadcast signals reception.

A Circuit for Simultaneous Reception of Data and Power Using a Solar Cell

This paper presents a circuit for simultaneous reception of optical power and data using a solar cell. The circuit employs a switched-inductor boost DC-DC converter for energy harvesting and a low-power thresholding receiver for data reception. The thresholding data receiver comprises a current-sense resistor that monitors the current output of the solar cell, an instrumentation amplifier, a band-pass filter and a comparator. A system-level analysis of an optical communication system employing the proposed circuit is presented along with a circuit-level analysis and implementation. As a proof-of-concept, the proposed circuit for simultaneous power and data reception is implemented using off-the-shelf components and tested using a custom-built test setup. Measurement results, including harvested power, electronic noise and bit error rate (BER), are reported for a GaAs solar cell and a red LED light source. Results show that 223 <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">$\mu \text{W}$ </tex-math></inline-formula> of power are harvested by the DC-DC converter at a distance of 32.5 cm and a radiated power of 9.3 mW. At a modulation depth of 50% and a transmission speed of 2.5 kbps, 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">$1.008\times 10^{-3}$ </tex-math></inline-formula> is achieved. Measurement results reveal that the proposed solution exhibits a trade-off between harvested power, transmission speed and BER.

Microwave Photonic Channelizer With Large Instantaneous Bandwidth Based on AOFS

The microwave photonic channelizer can convert the RF signal into the optical domain for transmission and procession, effectively avoiding the limitation of electronic bottleneck, and realizing the instantaneous reception of ultra-wideband signal or multi-frequency signals, which can be perfectly applied to radar system and electronic warfare. In this paper, a microwave photonic channelizer based on dual-output image-reject mixer is proposed, both the signal path and the local oscillator path are divided into three paths by using an optical coupler. An acousto-optic frequency shifter (AOFS) is used by the optical local oscillator to shift the frequency to the left and right and then enters the image rejection mixer with the signal path. Finally, a 6 GHz bandwidth RF signal is divided into six subchannels with a bandwidth of 1 GHz to achieve simultaneous reception. This scheme needs no optical frequency comb and doubles the channelization efficiency, the image rejection ratio of the sub-channels is about 22 dB, and the spurious-free dynamic range of the system can reach 103.2 dB·Hz <sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2/3</sup> .

SNR-Based GNSS-R for Coastal Sea-Level Altimetry

Geodetic Global Navigation Satellite System reflectometry (GNSS-R) uses ground-based signals of opportunity to retrieve sea levels at an intermediate spatial scale. Geodetic GNSS-R is based on the simultaneous reception of Line-of-Sight (LoS) and its coherent GNSS sea surface reflection (non-LOS) signals. The scope of this paper is to present geodetic GNSS-R applied to sea level altimetry. Signal-to-Noise Ratio (SNR) measurements from a Commercial Off-The-Shelf (COTS) geodetic-quality GNSS station at the Haiti Coast Guard Base in Port-au-Prince is used to retrieve sea levels in the International Terrestrial Reference Frame 2014 (ITRF2014). The GNSS-R sea levels are compared with those of the OTT Radar Level Sensor (RLS) installed vertically below the GNSS antenna. The Root-Mean-Square Error (RMSE) between the geodetic GNSS-R sea levels and OTT RLS records is 3.43 cm, with a correlation of 0.96. In addition, the complex differences between the OTT RLS records and 15-min GNSS-R sea levels using Global Positioning System (GPS) and Globalnaya Navigazionnaya Sputnikovaya Sistema (or Global Navigation Satellite System; GLONASS) signals for all the eight major tidal constituents are in mm-level agreement. Therefore, geodetic GNSS-R can be used as a complementary approach to the conventional method for sea level studies in a stable terrestrial reference frame.

Correction to: Development of a GNSS‑IR instrument based on low‑cost positioning chips and its performance evaluation for estimating the reflector height

Global Navigation Satellite System interferometric reflectometry (GNSS-IR) can be used to monitor a series of geophysical parameters in a cost-effective manner with high temporal resolution. The technique makes use of the simultaneous reception of direct and reflected GNSS signals with a single antenna. Based on the low-cost u-blox M8N chips, a GNSS-IR instrument is developed, which could be used to collect and process GNSS signals automatically and save and transmit generated GNSS data. Details about the instrument are described here for the first time. Then, the recorded SNR observation characteristics are analyzed by comparing three in-situ SNR sequences, which are simultaneously collected by the instrument with a low-cost patch antenna and a geodetic antenna and by a geodetic GNSS receiver with a geodetic antenna. Based on the developed function relating the peak power spectral density to peak frequency estimation error of the low-cost instrument, a weighting method is proposed to fuse multiple estimations of the reflector height to improve the estimation accuracy of the GNSS-IR-based reflector height. The performances of the developed low-cost instrument and the proposed reflector height estimation method are evaluated using a data set collected in Xinxiang City, Henan, China, over 6 days. The results show that there exists good agreement between the instrument-based reflector height estimates and the ground-truth estimates, with root-mean-square errors of 1.1 cm and 0.4 cm for the normal average and the proposed weighted average results, respectively, when the antenna height is in the range of 0.65 m to 2.15 m and the reflecting surface is flat, silty loam soil ground.

A tuneable rat-race coupler for full duplex communications

AbstractFull duplex (FD) could potentially double wireless communications capacity by allowing simultaneous transmission and reception on the same frequency channel. A single antenna architecture is proposed here based on a modified rat-race coupler to couple the transmit and receive paths to the antenna while providing a degree of isolation. To allow the self-interference cancellation (SiC) to be maximized, the rat-race coupler was made tuneable. This compensated for both the limited isolation of the rat race and self-interference caused by antenna mismatch. Tuneable operation was achieved by removing the fourth port of the rat race and inserting a variable attenuator and variable phase shifter into the loop. In simulation with a 50 Ω load on the antenna port, better than −65 dB narrowband SiC was achieved over the whole 2.45 GHz industrial, scientific and medical (ISM) band. Inserting the S-parameters of a commercially available sleeve dipole antenna into the simulation, better than −57 dB narrowband SiC could be tuned over the whole band. Practically, better than −58 dB narrowband tuneable SiC was achieved with a practical antenna. When excited with a 20 MHz Wi-Fi signal, −42 dB average SiC could be achieved with the antenna.

Centralized Dynamic-Time Division Duplex Utilizing Interference Alignment

In this paper, we combine centralized dynamic-time division duplex (D-TDD) with interference alignment (IA) for a wireless network comprised of <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">$N$ </tex-math></inline-formula> full duplex nodes. We maximize the performance of the proposed centralized D-TDD scheme utilizing IA in terms of rate region by optimizing the reception, transmission, simultaneous reception and transmission, and silence at each node in each time slot in addition to the choice of whether a node should treat the interference as noise or it should use IA. The problem of the rate region maximization of the wireless network is formulated as a non-convex optimization problem, whose optimal solution is found. The simulation results demonstrate that the proposed centralized D-TDD scheme utilizing IA achieves significant gains over the existing D-TDD schemes.