Relay Networks Research Articles

ER Oxidoreductin 1-Like Activity of Cyclic Diselenides Drives Protein Disulfide Isomerase in an Electron Relay System.

Disulfide formation generally involves a two-electron oxidation reaction between cysteine residues. Additionally, disulfide formation is an essential post-translational modification for the structural maturation of proteins. This oxidative folding is precisely controlled by an electron relay network constructed by protein disulfide isomerase (PDI), with a CGHC sequence as the redox-active site, and its family enzymes. Creating reagents that mimic the functions of these enzymes facilitates folding during chemical protein synthesis. In this study, we aimed to imitate a biological electron relay system using cyclic diselenide compounds as surrogates for endoplasmic reticulum oxidoreductin 1 (Ero1), which is responsible for the re-oxidation of PDI. Oxidized PDI (PDIox) introduces disulfide bonds into substrate proteins, resulting in its conversion to reduced PDI (PDIred). The PDIred is then re-oxidized to PDIox by a coexisting cyclic diselenide compound, thereby restoring the function of PDI as a disulfide-forming agent. The produced diselenol state is readily oxidized to the original diselenide state with molecular oxygen, continuously sustaining the PDI catalytic cycle. This artificial electron relay system regulating enzymatic PDI function effectively promotes the oxidative folding of disulfide-containing proteins, such as insulin-a hypoglycemic formulation-by enhancing both yield and reaction velocity.

Performance Analysis of Spatial Modulation Aided UAV Communication Systems in Cooperative Relay Networks

Performance Analysis of Spatial Modulation Aided UAV Communication Systems in Cooperative Relay Networks

Trajectory design of UAV-aided energy-harvesting relay networks in the terahertz band

Trajectory design of UAV-aided energy-harvesting relay networks in the terahertz band

Energy-Efficient Adaptive Bidirectional Transmission Strategy in Simultaneous Wireless Information and Power Transfer (SWIPT)-Enabled Cognitive Relay Network.

Introducing collaborative relay and simultaneous wireless information and power transfer (SWIPT) techniques into a cognitive wireless network, named the SWIPT-enabled cognitive relay network (CRN), is considered a promising approach to deal with insufficiency and the low utilization of spectrum resources, as well as the node's energy-constrained issues in wireless networks. In this paper, to improve the network spectrum efficiency (SE) and energy efficiency (EE) of the SWIPT-enabled CRN, we design an energy-efficient adaptive bidirectional transmission strategy. To be specific, we first select an energy-constrained best relay node with the consideration of signal-to-noise ratio and global channel gain to achieve a better bidirectional relay transmission (BRT). At the same time, we let the energy-constrained best relay node transmit a signal with the SWIPT technique, which can solve the node's energy-constrained issue and improve the network EE. Then, with the selected energy-constrained best relay node, we design a total transmit power threshold (TTPT) determining algorithm to find the TTPT, which lets the total transmission rate of the BRT be equal to the bidirectional direct transmission (BDT). Based on this TTPT, we further design an adaptive bidirectional transmission strategy and let the network achieve adaptive transmission between the BRT and BDT to obtain a higher network SE. Furthermore, to further achieve the energy-efficient transmission of the adaptive bidirectional transmission strategy, we optimize the nodes' power under the requirement of primary users' interference threshold and obtain the analytical expressions of the optimal power. Simulation results show that the transmission rate, the outage probability, and the EE of the designed energy-efficient adaptive bidirectional transmission strategy in the SWIPT-enabled CRN are, respectively, 3.01, 0.07, and 3.10 times that of the non-collaborative transmission, which show the effectiveness of our designed transmission strategy.

An Intelligent Coexistence Strategy for eMBB/URLLC Traffic in Multi-UAV Relay Networks via Deep Reinforcement Learning

An Intelligent Coexistence Strategy for eMBB/URLLC Traffic in Multi-UAV Relay Networks via Deep Reinforcement Learning

Symbol Error Analysis for Integrated Satellite- Terrestrial Relay Networks With Non-Orthogonal Multiple Access Under Hardware Impairments

Symbol Error Analysis for Integrated Satellite- Terrestrial Relay Networks With Non-Orthogonal Multiple Access Under Hardware Impairments

Correction to: Radio Resource Allocation Fairness in Cooperative Cognitive Radio Relay Networks

Correction to: Radio Resource Allocation Fairness in Cooperative Cognitive Radio Relay Networks

An Optimization Strategy for Security and Reliability in a Diamond Untrusted Relay Network with Cooperative Jamming

An Optimization Strategy for Security and Reliability in a Diamond Untrusted Relay Network with Cooperative Jamming

A Wireless Ad Hoc Network Communication Platform and Data Transmission Strategies for Multi-Bus Instruments

As automatic test technology advances, the number of programmable instruments in a single test system increases. Traditional wired communication methods have a limited range and involve complex cable layouts. Single-function wireless converters provide a viable alternative, but they have limitations. These include complicated configuration, issues with multi-system collaboration, and data blocking. This paper proposes a wireless ad hoc network platform for multi-bus instruments based on a low-cost ESP-12H WiFi module. The platform supports GPIB, RS232, RS485, and CAN bus interface instrument access. It features easy configuration, ad hoc networking, and self-repairing capabilities. A relay multi-hop network with a tree topology expands capacity and coverage. Additionally, a dynamic window-receiving mode and an improved multi-priority queue ensure data transmission integrity. The experimental results show that the platform’s networking time is less than 10 s, and the coverage range reaches 50 m in complex indoor environments. It also shows good stability when running for a long time. However, due to hardware and software design limitations, the actual upload speeds fall short of the theoretical values. For example, RS232 and RS485 are about 10% slower than the theoretical values, and GPIB is about 80% slower. Further optimization is required in the future.

A Secure Cooperative Image Super-Resolution Transmission with Decode-and-Forward Relaying over Rayleigh Fading Channels

In addition to susceptibility to performance degradation due to hardware malfunctions and environmental influences, wireless image transmission poses risks of information exposure to eavesdroppers. This paper delves into the image communications within wireless relay networks (WRNs) and proposes a secure cooperative relaying (SCR) protocol over Rayleigh fading channels. In this protocol, a source node (referred to as Alice) transmits superior-resolution (SR) images to a destination node (referred to as Bob) with the assistance of a mediating node (referred to as Relay) operating in decode-and-forward mode, all while contending with the presence of an eavesdropper (referred to as Eve). In order to conserve transmission bandwidth, Alice firstly reduces the size of the original SR images before transmitting them to Relay and Bob. Subsequently, random linear network coding (RLNC) is employed by both Alice and Relay on the downscaled poor-resolution (PR) images to obscure the original images from Eve, thereby bolstering the security of the image communications. Simulation results demonstrate that the proposed SCR protocol surpasses both secure relaying transmission without a direct link and secure direct transmission without relaying links. Additionally, a slight reduction in image quality can be achieved by increasing the scaling factor for saving transmission bandwidth. Furthermore, the results highlight the SCR protocol’s superior effectiveness at Bob’s end when compared to Eve’s, which is due to Eve’s lack of access to the RLNC coefficient matrices and reference images utilised by Alice and Relay in the RLNC process. Finally, the evaluation of reference images, relay allocations and diversity reception over Rayleigh fading channels confirms the effectiveness of the SCR protocol for secure image communications in the WRNs.

Consensus Optimal Filter for Linear Systems Over Amplify-and-Forward Relay Networks: Handling Delayed and Degraded Channels

Consensus Optimal Filter for Linear Systems Over Amplify-and-Forward Relay Networks: Handling Delayed and Degraded Channels

Physical layer security performance analysis in multi-antenna NOMA-based UAV relay networks

Physical layer security performance analysis in multi-antenna NOMA-based UAV relay networks

Controlled Power Cooperative Non Orthogonal Multiple Access Relay Networks

Controlled Power Cooperative Non Orthogonal Multiple Access Relay Networks

Beamforming design for IRS-and-UAV-aided two-way amplify-and-forward relay networks in maritime IoT

Beamforming design for IRS-and-UAV-aided two-way amplify-and-forward relay networks in maritime IoT

Effective capacity analysis of configurable intelligent surface-assisted NOMA communications systems

This paper investigates the integration of configurable intelligent surfaces (CIS) into relay radio networks, focusing on communication system enhancement. Towards this end, we propose CIS-assisted non-orthogonal multiple access (NOMA) communication systems to improve direct connections between a base station and two destination nodes. Our primary objective is to assess the net-work’s overall capacity, considering critical factors like signal-to-noise ratio, the number and placement of CIS components, quality of service exponent, and power distribution coefficients. Analytical equations developed in this research closely align with simulation results, validating our theoretical analysis. This study underscores the growing significance of CISs in modern communication systems, introducing adaptability and optimization to wireless networks. By exploring CIS-assisted NOMA communication systems, we contribute to dis-cussions about the evolving landscape of wireless communication technologies, poised to revolutionize information transmission and reception in the digital age.

Deep Reinforcement Learning-Based Energy Efficiency Optimization for RIS-Aided Integrated Satellite-Aerial-Terrestrial Relay Networks

Deep Reinforcement Learning-Based Energy Efficiency Optimization for RIS-Aided Integrated Satellite-Aerial-Terrestrial Relay Networks

Investigating cooperative strategies for security-reliability trade-off in full-duplex relay wireless networks

Investigating cooperative strategies for security-reliability trade-off in full-duplex relay wireless networks

A Mobile AD Hoc Network Relay Method based on OLSR Protocol

Aiming at the reliability and performance problems of data transmission in the complex mobile AD hoc network environment, a relay method is designed and implemented in the unstable network environment with complex dynamics such as mobile, multi-hop and no center according to practical needs. By introducing a prior link-state routing protocol, OLSR is introduced. Using range value judgment, sliding window statistics and improved multi-point relay selection technology, it can effectively reduce the redundancy of relay node set, reduce the forwarding frequency of service data in the network, save the network overhead, and ensure the data transmission delay and quality in the large scale and dense mobile AD hoc network.

Achievable secrecy rate analysis of OFDM‐based multi‐user untrusted relay networks with imperfect CSI

AbstractThis study investigates the impact of imperfect channel state information (CSI), caused by channel estimation errors and feedback delays, on the physical‐layer security performance of multi‐user relay networks. More specifically, a multi‐user untrusted half/full‐duplex (HD/FD) uni/bi‐directional wireless amplify‐and‐forward (AF) relay network is studied, adopting orthogonal frequency division multiplexing (OFDM). In order to minimize the information leakage, it is considered that a limited number of friendly jammers affect the untrusted relay. In this context, the achievable secrecy rate of the relay network is theoretically analyzed and optimization problems are formulated and solved for the untrusted relay's location and power allocation. Monte Carlo simulations are conducted to validate the theoretical findings, revealing that channel estimation errors cause coding gain losses for low signal‐to noise ratio (SNR) while their impact becomes negligible for high SNR. Also, a large number of user‐pairs achieves higher secrecy rate while FD relaying further improves the secrecy performance. Finally, bi‐directional relaying provides higher achievable secrecy rate over uni‐directional relaying.

On-Demand Multiplexing of eMBB/URLLC Traffic in a Multi-UAV Relay Network

On-Demand Multiplexing of eMBB/URLLC Traffic in a Multi-UAV Relay Network