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Fixed Relaying

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lightbulbAbout this topic
Fixed relaying refers to a communication technique in networking where a stationary device receives, amplifies, and retransmits signals to extend the range of communication. It is commonly used in wireless networks to enhance signal strength and coverage without altering the original signal's content.
lightbulbAbout this topic
Fixed relaying refers to a communication technique in networking where a stationary device receives, amplifies, and retransmits signals to extend the range of communication. It is commonly used in wireless networks to enhance signal strength and coverage without altering the original signal's content.

Key research themes

1. How can fusion strategies in balanced binary relay trees optimize distributed detection error probabilities?

This research area focuses on the design and optimization of fusion rules in hierarchical fixed relaying networks, particularly balanced binary relay trees, to minimize detection error probabilities in distributed detection settings. It is essential because relay nodes aggregate sensor data to enable accurate global decisions with communication and computational efficiency constraints. Understanding optimal fusion strategies and their properties in relay trees advances the theory and practice of sensor networks and related applications.

Key finding: Formulated the globally optimal fusion strategy in balanced binary relay trees as a dynamic program characterized by Bellman equations, and introduced the notion of string-submodularity for fusion rules. Demonstrated that the... Read more

2. What algorithms improve relay node placement to minimize communication cost and connectivity in fixed wireless sensor networks?

This theme investigates algorithmic solutions to optimally place relay nodes in fixed wireless sensor networks to ensure connectivity between sensors and basestations while minimizing deployment cost and communication overhead. It addresses geometric, graph-theoretic, and computational challenges within normed spaces (especially Euclidean space) and introduces approximation and heuristic algorithms with provable performance bounds. Improving relay placement reduces network energy consumption and enhances communication reliability in sensor deployments.

Key finding: Developed a (1 + ln 6 + ǫ)-approximation algorithm for single-tiered relay placement connecting sensors and basestations in 2D Euclidean space, improving previous approximation ratios. Proposed strategies adapt to... Read more
Key finding: Modeled relay placement as joint optimization of relay locations and routing to minimize packet retransmissions (communication cost). Proved APX-hardness of discrete relay selection and developed an exponential-time optimal... Read more

3. How do measurement and testing methodologies using relay data formats enhance fixed relay protection system performance evaluation?

This theme covers methodologies that utilize digital fault recorders (DFR), relay COMTRADE files, and microprocessor-based test systems to record, analyze, and test protective relay operations in fixed relay systems. It tackles challenges in diagnosing relay maloperation, validating settings, and improving relay functionality under transient events and fault scenarios. Efficient data-based evaluation ensures relay reliability and security, critical in power system protection and grid stability.

Key finding: Presented a novel method for extracting six-phase relay input currents from standardized COMTRADE files to generate the differential relay's differential trajectory mapped onto its setting curve. This extraction accounts for... Read more
Key finding: Implemented an automated system for analyzing protection system operation using data from Digital Fault Recorders and relay COMTRADE files across a diverse relay technology spectrum from electromechanical to digital numerical... Read more
Key finding: Designed and implemented a microcontroller-based protective relay tester capable of performing steady state, dynamic state, and transient tests using data from digital fault recorders and simulation tools. The system supports... Read more

All papers in Fixed Relaying

Wireless cellular networks have to be designed and deployed with unavoidable constrains on the limited radio resources such as bandwidth and transmit power. The primary objective of this paper is to improve the capacity and utilization of... more
The core aim of this work is the maximization of the achievable data rate of the secondary user pairs (SU pairs), while ensuring the QoS of primary users (PUs). All users are assumed to be equipped with multiple antennas. It is assumed... more
The ever-increasing demand for mobile Internet and high-data-rate applications poses unique challenging requirements for 5G mobile networks, including spectrum limitations and massive connectivity. Cognitive radio and carrier aggregation... more
In this paper, we investigate joint relay selection and optimal power allocation, as a means to maximize the achievable rate of an underlay cooperative cognitive radio with carrier aggregation, taking into account the availability of... more
We examine the impact of multiple primary transmitters and receivers (PU-TxRx) on the outage performance of cognitive decode-and-forward relay networks. In such a joint relaying/spectrum-sharing arrangement, we address fundamental... more
Outage performance of a cognitive multi-relay system using imperfect channel state information (CSI) of interfering links is formulated in this paper. In the considered cognitive system, it is assumed that wireless channels in the... more
We examine the impact of multiple primary transmitters and receivers (PU-TxRx) on the outage performance of cognitive decode-and-forward relay networks. In such a joint relaying/spectrum-sharing arrangement, we address fundamental... more
Two novel spectrum access schemes, a hybrid spectrum access scheme (HSAS) and a modified HSAS combining underlay mode and overlay mode, are proposed for a relay based cognitive radio (CR) network. The CR employs the underlay mode with... more
We examine the impact of multiple primary transmitters and receivers (PU-TxRx) on the outage performance of cognitive decode-and-forward relay networks. In such a joint relaying/spectrum-sharing arrangement, we address fundamental... more
Outage performance of a cognitive multi-relay system using imperfect channel state information (CSI) of interfering links is formulated in this paper. In the considered cognitive system, it is assumed that wireless channels in the... more
In this study, the authors investigate the performance of opportunistic scheduling for the dual-hop amplify-andforward multiuser cognitive relaying network. Expressions are derived for the cumulative distribution function (CDF) and... more
We examine the impact of multiple primary transmitters and receivers (PU-TxRx) on the outage performance of cognitive decode-and-forward relay networks. In such a joint relaying/spectrum-sharing arrangement, we address fundamental... more
Outage performance of a cognitive multi-relay system using imperfect channel state information (CSI) of interfering links is formulated in this paper. In the considered cognitive system, it is assumed that wireless channels in the... more
Outage performance of a cognitive multi-relay system using imperfect channel state information (CSI) of interfering links is formulated in this paper. In the considered cognitive system, it is assumed that wireless channels in the... more
We propose and analyze the performance of fullduplex relay selection in primary/secondary spectrum-sharing networks. Contrary to half-duplex relaying, full-duplex relaying (FDR) enables simultaneous listening/forwarding at the secondary... more
In this letter, we propose two power allocation strategies, named Optimal Power Allocation (OPA) and Equal Intercept Probability (EIP), for dual-hop cooperative decode-and-forward (DF) relaying networks under constraint of intercept... more
NENAD MILOSEVIC, 12 ZORICA NIKOLIC, 1 BOJAN DIMITRIJEVIC 1 In this paper we consider performance of a cooperative system consisting of dual hop amplify-and-forward relay system. We consider channel state information assisted system in... more
Outage performance of a cognitive multi-relay system using imperfect channel state information (CSI) of interfering links is formulated in this paper. In the considered cognitive system, it is assumed that wireless channels in the... more
In this paper, the outage behavior of dual-hop multiuser multirelay cognitive radio networks under spectrum-sharing constraints is investigated. In the proposed cognitive radio network, the secondary network is composed of one... more
In a spectrum sharing underlay context, we investigate the exact derivation of the outage probability for relay-aided cognitive radio communications. To give more degrees of freedom to the secondary system in acquiring a targeted... more
In a spectrum sharing underlay context, we investigate the exact derivation of the outage probability for relay-aided cognitive radio communications. To give more degrees of freedom to the secondary system in acquiring a targeted... more
Distributed switch-and-stay combining (DSSC) has been envisioned as an effective transmission technique to achieve spatial diversity in a distributed fashion, with low implementation complexity. In this paper, we take a step further to... more
In this work, the half-duplex (HF) power beacon-assisted (PB) energy harvesting (EH) relaying network, which consists of a source (S), Relay (R), destination (D) and a power beacon (PB) are introduced and investigated. Firstly, the... more
In this paper, the outage behavior of dual-hop multiuser multirelay cognitive radio networks under spectrum-sharing constraints is investigated. In the proposed cognitive radio network, the secondary network is composed of one... more
Cognitive radio has been proposed in order to promote spectrum utilization by exploiting the spectrum holes. Observing the spectrum resources can be matched to traffic demand of secondary users with the help of relay node. In this article... more
Cognitive radio has been proposed in order to promote spectrum utilization by exploiting the spectrum holes. Observing the spectrum resources can be matched to traffic demand of secondary users with the help of relay node. In this article...