Signal Reception Research Articles

Audience Perceptions on Online Radio Platforms: A Case of University Students in Nyanza Region, Kenya

The purpose of this study was to examine audience perceptions of online radio platforms among university students in the Nyanza region. The study’s objectives included assessing audience perception of the programming of online radio platforms among university students in the Nyanza region, evaluating audience perception of signal reception of online radio platforms among university students in the Nyanza region, investigating audience perception of programs aired on online radio platforms among university students in the Nyanza region, and analyzing audience perception of program presentation of online radio platforms among university students in the Nyanza region. This study was underpinned by the framing theory and the agenda-setting theory. The research employed a descriptive research design. The target population was 872 media studies undergraduate students in six universities in the Nyanza region. Stratified random sampling was utilized to select 274 students in each of the universities. Data were collected through semi-structured questionnaires, and a pilot study was conducted at Rongo University. The study used questionnaires for accuracy and consistency, and data were cleaned and analyzed using the Statistical Package for Social Sciences software. Descriptive statistics were employed to examine audience perception of online radio platforms. A thematic analysis approach was used to identify recurring themes and to explore participants' perspectives. Data were presented using graphs, pie charts, and tables. Findings revealed that online radio provided higher quality programming compared to traditional radio. Results indicated that signal reception on online radio platforms was consistently reliable. According to the findings, programs aired on online radio platforms were engaging and interesting. Results indicated that the presentation style of programs on online radio platforms was professional. The study concludes that diverse and high-quality content on online radio platforms caters to varied interests, offering clear audio and stable listening experiences. Engaging and well-structured programs meet entertainment needs, recommending the development of new genres, topics, and formats to stay relevant. Quality programming, optimized scheduling, and innovative content delivery methods are essential for maintaining listener satisfaction and competitiveness in the media industry.

Optimizing Communication for a Humanoid Subs-Talker Robot Using RSSI Analysis on ROS System

This study aims to optimize communication for the humanoid "Subs-Talker" robot using Receive Signal Strength Indicator (RSSI) analysis within the Robot Operating System (ROS). The background of this research highlights the importance of stable and strong inter-robot communication in the Indonesian Humanoid Robot Soccer Contest (KRSBI-H), where robots need to function in synergy. The method involves measuring signal strength at specific distances, both with and without the use of an extender device, utilizing the InSSIDer application for RSSI data recording and analysis. The results show that using an extender improves communication stability, especially at longer distances (7.2 and 9.0 meters), although the impact is minimal at closer distances. The discussion suggests that an extender can be an effective solution for enhancing inter-robot communication quality in competitions. In conclusion, the extender significantly improves the communication range and signal quality among robots, supporting optimal performance in collaborative robot interactions within the competition arena.

MIMO and PDM-based intersatellite optical link for high-speed data transfer and remote sensing application.

Inter-Satellite Optical Wireless Communication (Is-OWC) is a pivotal technology for advancing global connectivity and the effectiveness of space-based operations. It serves as the linchpin for various applications such as global internet coverage, Earth observation, and remote sensing, bolstering our capacity to monitor the planet and deliver essential services. This paper presents the design and performance evaluation of a Polarization Division Multiplexing (PDM) and Multiple Input Multiple Output (MIMO)-based Is-OWC system operating at a data rate of 60 Gbps. The system was tested under varying transmission distances, atmospheric turbulence, and pointing error conditions. At a transmission distance of 10,000 km, the system achieved a Bit Error Rate (BER) of 6.76 × 10⁻3 for Channel 1 (X polarization) and 7.1 × 10⁻3 for Channel 4 (Y polarization), both within Forward Error Correction (FEC) limits. The introduction of a 4 × 4 MIMO configuration extended the transmission range to 14,000 km, with a corresponding BER of 9.1 × 10⁻3 for Channel 1 and 8.7 × 10⁻⁵ for Channel 4. Eye diagrams confirm successful signal reception, demonstrating that the system can maintain high data rates and low error rates over long distances. The proposed PDM-MIMO system showcases high-capacity, robust performance under challenging conditions, such as turbulence and pointing errors, validating its suitability for space-based communication applications. These findings highlight the potential of the system for future deployments in satellite networks, offering reliable, high-throughput, and low-latency data transmission over extended distances.

Statistical analysis of the matrix method for measuring the radar characteristics of objects

The matrix method for measuring the radar characteristics of objects is examined. The method involves irradiating the object with a system of independent test fields, receiving the set of scattered fields, and performing posterior processing of the obtained results based on the superposition principle to determine the required radar characteristics of the object. An analysis of the information capabilities of the matrix method for measuring linear and nonlinear radar characteristics of objects is conducted, considering random errors in the registration of the amplitude and phase of the test signals. The variances of the desired linear and nonlinear radar characteristics of objects are determined, assuming a high signal-to-noise ratio in each test signal reception channel and maximum likelihood estimation of the amplitude and phase of the test signals. It is established that the matrix method for measuring radar characteristics of objects is functional under real conditions involving noise and interference.

The Application of Multiple Input Multiple Output (MIMO) Technology in Wireless Communications

Abstract: With the rapid advancement of wireless communication technology, enhancing data transmission rates, system capacity, and reliability has emerged as a key challenge. The paper investigates the application of Multiple Input Multiple Output (MIMO) antenna technology in wireless communication. By using multiple antennas for simultaneous signal transmission and reception, MIMO technology can effectively mitigate multipath effects and enhances channel capacity. And channel models of MIMO systems, capacity optimization strategies, and power allocation methods are also discussed. The results indicate that MIMO technology significantly improves transmission rates and signal quality in complex propagation environments. However, practical applications continue to face challenges such as channel estimation errors and antenna correlation. Therefore, the paper highlights the significance of MIMO technology in wireless communication systems and outlines potential directions for future research.

A wideband circularly polarized four port microstrip MIMO antenna with high gain and enhanced isolation for 5G millimeter frequency applications

Abstract In this article, a MIMO antenna system featuring wide bandwidth, high gain, and circular polarization for 5G communication networks is presented. The proposed antenna enables high data rates, enhanced signal reliability, and improved performance in dynamic and challenging 5G environments. Wide bandwidth ensures compatibility with various 5G frequency bands, while circular polarization allows for better signal propagation and reception, particularly in non-line-of-sight scenarios. In that regard, the present endeavor exhibits an enhanced bandwidth 4-port circularly polarized MIMO antenna to encounter polarization mismatch along with high data rates. The presented MIMO antenna comprises four identical patches strategically positioned in orthogonal orientations in such a way as to provide the circular polarization direction. Meanwhile, the bandwidth is extended by inserting straightforward defected ground structure (DGS) and L slots. The MIMO antenna anticipated in this work offers an impedance bandwidth covering from 24 GHz to 28.5 GHz and an axial ratio bandwidth of 62% within the overall band. It demonstrates excellent performance with a high peak gain of approximately 14.84 dB. Additionally, it exhibits strong isolation of more than 20dB among the closely packed antennas, ensuring reliable communication and minimizing interference. The combination of these features in a MIMO antenna system is crucial for meeting the demanding requirements of 5G communication, including increased data capacity, low latency, and reliable connectivity. The simulated and measured outcomes exhibit robust concurrence, signifying a high level of accuracy. Consequently, the suggested MIMO antenna appears well-suited for encompassing the 5G bands designated for deployment in the USA (27.50–28.35 GHz) and Europe (24.25 - 27.5 GHz).

Review on HF Band Vehicular Antenna with NVIS Communication

Antennas play a fundamental role in modern communication systems by facilitating signal transmission and reception across various frequency bands. Each antenna is designed for specific applications based on its operating frequency range. Whether deployed for Car-to-Car Communication or military operations, antennas serve critical functions, with information security being paramount in military contexts. Vehicular antennas typically operate within the L Band, approximately 1 to 2 GHz, relying on satellites for signal communication. However, traditional transmission through the ionosphere faces limitations, notably the skip zone, where signal reception is hindered, leading to communication failures. To address this limitation, Near Vertical Incident Skywave (NVIS) communication has been developed. NVIS utilizes antennas with very high (> 75°) radiation angles and low HF frequencies to overcome skip zone challenges. Despite existing research efforts, achieving high radiation efficiency remains a challenge, often due to improper antenna angle settings. Additionally, previous studies have overlooked the importance of narrow beam focusing, crucial for long-range communication and direction finding. This paper aims to enhance antenna performance parameters such as efficiency and gain through the adoption of specific techniques. By optimizing antenna design and configuration, we aim to improve performance for ionospheric communication, particularly in military applications involving data and voice transmission.

Research on dynamic solution analysis and applications based on the Rydberg atom superheterodyne structure

This paper investigates the dynamic solution of the density matrix equation based on the Rydberg atom superheterodyne structure. Compared to the current analytical method relying on the steady-state solution, the dynamic solution is related to the Rabi frequency and the frequency of the signal to be measured. Therefore, it can comprehensively describe the instantaneous bandwidth and gain characteristics of the receiver and is in good agreement with experimental results. Additionally, we propose an atomic all-heterodyne receiver architecture that combines electric-field heterodyne and optical heterodyne techniques and demonstrates the reception and recovery of modulated signals under this architecture with linear frequency modulation (LFM) signals as an example. Our research offers interesting theoretical insights that can be applied to the performance analysis and system optimization of atomic receivers.

Improved EMAT Sensor Design for Enhanced Ultrasonic Signal Detection in Steel Wire Ropes

This study is focused on optimizing electromagnetic acoustic transducer (EMAT) sensors for enhanced ultrasonic guided wave signal generation in steel cables using CAD and modern manufacturing to enable contactless ultrasonic signal transmission and reception. A lab test rig with advanced measurement and data processing was set up to test the sensors’ ability to detect cable damage, like wire breaks and abrasion, while also examining the effect of potential disruptors such as rope soiling. Machine learning algorithms were applied to improve the damage detection accuracy, leading to significant advancements in magnetostrictive measurement methods and providing a new standard for future development in this area. The use of the Vision Transformer Masked Autoencoder Architecture (ViTMAE) and generative pre-training has shown that reliable damage detection is possible despite the considerable signal fluctuations caused by rope movement.

Direct characterisation of AM-to-PM phenomena in fast Si and InGaAs photodiodes

The direct measurement method of AM-to-PM phenomena in fast silicon and InGaAs photodiodes is described. The setup is simple, relatively inexpensive and allows fast and precise measurements not only in a laboratory environment. During sample tests, the authors have found that the influence of bias voltage on the phase shift of an optical signal conversion is significant. The reported effect together with the influence of modulation depth on phase shift (AM-to-PM conversion) has a negative impact on an optical signal reception especially in coherent applications. The authors show that, with our proposed setups, it is possible to find optimal bias voltage and optimal optical power in order to reduce electrical phase noise of the photodetector.

Feed system tracking receive/transmit shaped Cassegrain antenna C/K bands

Background. The need to create, space communication stations based on mobile carriers, for example, on ships, requires the use of multi-band reflector antennas irradiating systems that ensure the combination of not only channels for receiving and transmitting high-frequency signals, but also direction-finding channels for constructing a monopulse tracking system. Aim. Study of the possibility of creating an irradiation system that ensures the combination of reception and transmission of signals in the multi-band reflector antenna in spaced ranges with frequency bands C(Rx) – 21 %, C(Tx) – 16 % and K(Rx) – 21 %, with the implementation of a monopulse angular automatic tracking system in both receiving ranges. Methods. Development of a three-band irradiation system that ensures the implementation of automatic tracking in both receiving ranges. Analysis of the characteristics of a three-band irradiation system that ensures the implementation of reception and automatic tracking in both receiving ranges. Results. Development of a three-band irradiation system that ensures the implementation of automatic tracking in both receiving ranges. Analysis of the characteristics of a three-band irradiation system that ensures the implementation of reception and automatic tracking in both receiving ranges. Conclusion. The irradiation system of the multi-band reflector antenna for mirrors with profiled surfaces is proposed, with the implementation of combined signal reception in the C(Rx) and K(Rx) frequency ranges with a 21 % band and signal transmission in the C(Tx) frequency range with a 16% band, and the formation of partial RPs in both receiving ranges for the implementation of a monopulse angular tracking system. The following characteristics of the irradiation system are implemented: cross-polarization isolation of more than 30 dB, the formation of identical partial RPs and a stable tracking mode based on signals from onboard repeaters in communication systems with frequency reuse.

Research and Design of BPM Shortwave Time Signal Modulation Technology Based on Chirp

The shortwave time service system is a vital land-based wireless time service solution, serving as a supplement and backup to the global navigation satellite system. It ensures that time users can access reliable timings, especially in extreme situations. However, the current BPM shortwave time service signal in China faces issues such as insufficient anti-interference reception capabilities and poor timing accuracy. This paper capitalizes on the advantages of Chirp signals and explores a new modulation technology for BPM shortwave time signals that is compatible with the existing modulation system. A Dual Chirp Time-Division Combined Modulation (DCTDCM) scheme is proposed for broadcasting two time signals: Coordinated Universal Time (UTC) and Universal Time 1 (UT1). Furthermore, an in-depth study of the receiving method for this scheme is conducted, with detailed design of its parameters. The designed DCTDCM signals offer a spread spectrum gain of 24 dB and a multipath resolution capability of at least 125 μs, significantly enhancing the anti-interference reception and anti-multipath attenuation capabilities of shortwave time signals. As a result, the availability and timing accuracy of shortwave time signals are substantially improved. Finally, extensive comparative experiments on reception performance validate the effectiveness of this approach.

Ancestral neural circuits potentiate the origin of a female sexual behavior in Drosophila

Courtship interactions are remarkably diverse in form and complexity among species. How neural circuits evolve to encode new behaviors that are functionally integrated into these dynamic social interactions is unknown. Here we report a recently originated female sexual behavior in the island endemic Drosophila species D. santomea, where females signal receptivity to male courtship songs by spreading their wings, which in turn promotes prolonged songs in courting males. Copulation success depends on this female signal and correlates with males’ ability to adjust his singing in such a social feedback loop. Functional comparison of sexual circuitry across species suggests that a pair of descending neurons, which integrates male song stimuli and female internal state to control a conserved female abdominal behavior, drives wing spreading in D. santomea. This co-option occurred through the refinement of a pre-existing, plastic circuit that can be optogenetically activated in an outgroup species. Combined, our results show that the ancestral potential of a socially-tuned key circuit node to engage the wing motor circuit facilitates the expression of a new female behavior in appropriate sensory and motivational contexts. More broadly, our work provides insights into the evolution of social behaviors, particularly female behaviors, and the underlying neural mechanisms.

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.

Research on AUV Multi-Node Networking Communication Based on Underwater Electric Field CSMA/CA Channel

To address the issues of high attenuation, weak reception signal, and channel blockage in the current electric field communication of underwater robots, research on autonomous underwater vehicle (AUV) multi-node networking communication based on underwater electric field Carrier Sense Multiple Access with Collision Avoidance (CSMA/CA) channel was conducted. This article, first through simulation, finds that the Optimized Link State Routing (OLSR) protocol has a smaller routing packet delay time and higher reliability compared to the Ad Hoc On-Demand Distance Vector (AODV) protocol on underwater electric field CSMA/CA channels. Then, a 2FSK underwater electric field communication system was established, and dynamic communication experiments were carried out between two AUV nodes. The experimental results showed that within a range of 0 to 3.5 m, this system can achieve underwater dynamic electric field communication with a bit error rate of 0 to 0.628%. Finally, to avoid channel blockage during underwater AUV multi-node communication, this article proposes a dynamic backoff method for AUV multi-node communication based on CSMA/CA. This system can achieve dynamic multi-node communication of underwater electric fields with an error rate ranging from 0 to 0.96%. The research results have engineering application prospects for underwater cluster operations.

Devising a method for detecting an aerial object by radar with an additional channel of passive reception

The object of this paper is the process of detecting an aerial object by a radar with active and passive reception channels. The main hypothesis of the study assumed that the introduction of an additional channel of passive reception would increase the conditional probability of correct detection at a fixed value of the conditional probability of false alarms. When detecting an aerial object, it was considered that the signals from aerial object represent a reflected signal after being emitted by the active radar channel elemitted own radio signals. A radar with active and passive reception channels assumes the presence of two channels. The active location channel provides reception of signals reflected from an aerial object, their processing and detection according to the Neumann-Pearson criterion. The passive location channel functions according to the principle of panoramic spectral analysis based on windowed Fourier transforms. The information combining device is intended for the compatible combining of information from active and passive channels of radar reception. At the output of the passive location channel, an output signal is formed, and the coordinates of the aerial object are measured. To ensure the functioning of the radar with active and passive reception channels, it is necessary to ensure the time synchronization of the reception channels. The quality of detection of aerial objects by radar with active and passive signal reception channels was evaluated. The quality indicator defines the conditional probability of correct detection. The dependences of the conditional probability of correct detection are given for a radar with only an active reception channel and a radar with active and passive reception channels. It was established that the introduction of an additional channel of passive reception to the radar increases the conditional probability of correct detection by an average of (20–40) %, depending on the signal-to-noise ratio.

An Automatic Mapping Method of Navigation Map for Outdoor Road Scenes

Abstract. In the process of autonomous navigation of outdoor mobile robots, four modules are involved: perception, localization, planning, and controlling. The perception module utilizes sensors such as cameras and radars based on various principles to analyze the robot's surroundings in real-time. The localization module uses GPS (Global Positioning System), IMU (Inertial Measurement Unit), and prior maps for real-time positioning analysis. The planning module plans optimal path based on the outputs of the first two modules, and the controlling module directs the robot's chassis to move along the planned optimal path. For the localization module, the accuracy of GPS positioning results heavily depends on weather conditions and GPS signal receptions. Even if the positioning results of imu are integrated, the positioning accuracy still cannot meet the needs of robot navigation. Therefore, using prior maps for repositioning can compensate for this accuracy deficiency. The planning module also requires path planning based on prior maps. If the a priori map storage is large, it will lead to difficulties in usage, maintenance, and updates. Therefore, it is crucial to research lightweight navigation map mapping methods. In this paper, an automatically mapping method of lightweight navigation maps is proposed, combining cameras and LiDAR (Light Detection and Ranging), including semantic informations necessary for outdoor navigation positioning, such as pole-like objects and traffic signs for robot longitudinal positioning, and lane line elements for robot lateral positioning. This method automatic generates robot navigation maps in Lanelet2 format, providing support for subsequent positioning and path planning modules.

Network Coding Schemes and Cooperative Communication Systems Amplify and Forward in Outdoor Environments

Fading is a phenomenon of decreasing signal strength during transmission, caused by changes in environmental conditions or physical obstacles in the propagation path. Fading can cause interference in signal reception, such as distortion or loss of information, especially in Non-Line of Sight (NLoS) paths, where signals must pass through many paths or obstacles such as buildings, trees, or other objects. To eliminate fading interference, a cooperative communication system is created to reduce the effects of fading in wireless networks. The cooperative communication system works by utilizing other nodes in sending signals to the destination. The relay protocol used in this study is amplify and forward, where the signal to be sent will be amplified and forwarded to the destination by the relay node. A network coding scheme is added to the cooperative communication system to improve network performance. This scheme encodes each piece of information with the XOR technique. The parameters used in measuring the network coding scheme in the cooperative communication system are BER and throughput. Viewed from the BER value, the conventional cooperative communication system has better performance compared to the cooperative communication system with network coding. Cooperative communication system scheme without NC BER value is 0 when the transmit power value is -19 dBm or Gain 32. While for the cooperative communication system scheme with network coding BER value is 0 when transmit power of -9.25 dBm. Throughput system with network coding has increased by 17% compared to the conventional system.

Implementation of Software for Learning Message Transmission Using Morse Code

The article presents the implementation of software for training message transmission using Morse code. This is a method of sign coding when letters of the alphabet, numbers, punctuation marks and other symbols are represented as sequences of short and long signals called dots and dashes. It is intended for transmission over serial communication channels. A unique feature of Morse code is the ability to be encoded and decoded by humans without the use of special terminal devices. The paper shows a software implementation of processing input characters using a telegraphic key, it includes: various mathematical requirements and conditions that allow you adjusting to each user, provided that his input speed will either fall or remain unchanged. However, it is possible to adjust the minimum duration threshold in such a way that the system will slowly adapt to a slow increase in input speed. At the same time, the higher the value of the minimum threshold, the faster the adaptation is; however, it will fall within the limit of the maximum input speed that the device can recognize. During the implementation of the program, a flow chart of message transliteration, signal reception and transmission was developed. The whole program implements the following functions: a simple and intuitive translator, with audio output, a simulator for consolidating the skill of entering Morse code using a key; consolidating the skills of recognition and decoding by ear. To create the final application for training, the Processing toolkit was chosen, since its key parameter when choosing a development tool has a simple writing syntax to increase the speed of writing code, as well as the ability of the environment to work with the communication channel of the microcontroller.

Noise immunity of QAM-OFDM signal reception using soft-decision demodulation in the presence of narrowband interference

Noise immunity of QAM-OFDM signal reception using soft-decision demodulation in the presence of narrowband interference