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In this paper, the system-level performance of nonorthogonal multiple access (NOMA) in coordinated direct and relay transmission (CDRT) is investigated. Considering a successive interference cancellation (SIC) receiver under the 3D channel model for LTE, the system-level performance of the NOMA-CDRT is compared to the NOMA in non-coordinated direct and relay transmission (nCDRT). Simulation results...
In this paper, a vertical physical-layer network coding (VPNC) scheme based pulse amplitude modulation (PAM) for two-way relay channel (TWRC) is proposed. Different from the conventional physical layer network coding (PNC) scheme in which the relay superimposes two users' signals of the same constellation, in the proposed VPNC scheme two users transmit PAM signals with vertical constellation and the...
In this paper, we consider a two-hop cooperative relaying network in a randomly distributed interference environment, where the source communicates with the destination, assisted by N decode-and-forward (DF) relays. We consider the interference-limited environments, where the received signals at the relays and the destination are degraded by random interference nodes distributed according to homogeneous...
The existing half-duplex relay-based device-to-device (D2D) communication equips with single antenna infrastructure and receives and transmits signals in two equivalent slots which lead to poor performance in term of rate achievement. To solve this problem, we propose a new relay-based D2D scheme with two-antenna infrastructure and bring in slot splitting factor to divide one frame into double unequal...
In this paper, an improved cooperative jamming (CJ) strategy is developed for physical layer (PHY) security in a multi-hop wireless communication system which employs beamforming in the last hop. Users are assigned to independent groups based on the merger-and-split rule in a coalition game. The secrecy capacity for a valid coalition is a non-convex optimization problem which cannot easily be solved...
This paper investigates the performance of a cooperative spectrum sharing protocol for cognitive two-way amplify-and-forward (AF) relaying system. In the proposed framework, two primary users (PUs), PU1 and PU2 coexist with a secondary user (SU) in the same frequency band albeit with different priorities. Primary users by virtue of having a license to operate over the frequency band have higher priority...
Efficient content retrieval is crucial for Named Data Delay Tolerant Networking (NDDTN). Previous studies have shown that using social properties reasonably can improve availability of forwarding data packets, reduce overhead and delay. In this paper, a forwarding strategy, called RIF based on Region of Interest (ROI), is proposed and put forward for NDDTN. RIF computes cumulative visiting time and...
Multi-hop wireless broadcast is an important component of vehicular networks. Many services rely on the performance of broadcast communication to disseminate data packets. In an urban vehicular network, an efficient way of broadcasting data packets is choosing some vehicles as relay nodes. The base station only needs to multicast data packets to these relay vehicles and the packets would be spread...
Vehicular communication systems have significant benefits. Their adoption and use in motor vehicles can help prevent road traffic accidents, increase route efficiency and fuel economy, and positively impact the user experience. As autonomous vehicles and inter-vehicular communication systems are becoming increasingly commonplace, the need for robust and secure wireless communication between vehicles...
Operational Amplifiers are widely used for implementing simple and complex electronic circuits in electronic engineering. As a contribution to improve the way this integrated circuit is included in electronic engineering courses' curricula, this paper presents a prototype of an educational kit comprising a simulation tool and a reconfigurable hardware platform with the OpAmp uA741. It enables the...
In this letter we introduce a self-interference (SI) cancelation technique for amplify and forward relays. Relays are used to help forward signals between a transmitter and a receiver. This helps increase the signal coverage and reduce the required transmitted signal power. One issue that faces relays communications is the SI problem where an unwanted leaked signal from the relay's output will contaminate...
In this paper, a cooperative device to device (D2D) communication system is studied while two transmitting devices communicate with one destination device in the presence of a passive eavesdropper. The second transmitting device cooperates with the first transmitting device and hence the transmission takes place is two phases. In the first phase, the first device transmits its signal to the second...
The Prophet routing algorithm is a multi-copy algorithm which is based on historical information and transitive probability, which selects the relay node with a high probability to encounter the destination node. However, the selection of a relay node does not consider the current congestion level of node. Even if the current relay node has a high delivery probability to the destination node, it may...
Since it is challenging to position the noncooperative receiver (Rx), especially when the backward frequency band of the Rx cannot be obtained by the anchors. In this paper, we propose a novel noncooperative Rx positioning method using full-duplex relay technique, where the anchors act as full-duplex relays for the Rx. It can trigger the close-loop-power-control (CLPC) between the transmitter (Tx)...
In the future millimeter-wave small-cell communication systems, relay cooperation is deemed as one of the promising techniques to realize green communication. In relay cooperative system, the selected relaying mode determines the system performance in some extent. For the commonly used modes, amplify-and-forward (AF) and decode-and-forward (DF), which one should be taken in specific scenario? In this...
In this paper, the security of multi-input single- output (MISO) amplify-and-forward relaying network with untrustworthy relay nodes is considered, where the untrustworthy nodes can help to forward the received signal and they may also try to decode such information, which can be regarded as potential eavesdroppers (Eves). To deal with such kind of smarter Eves, relay selection is adopted and both...
The study of secrecy capacity of wireless networks, considering variety of powerful attacks is currently of great interest. In this paper, we have considered a possible attack scenario where an eavesdropper is present as a legitimate relay node in disguise in the network. A novel scheme of simultaneous transmission of jamming signal and message signal is proposed to confuse the eavesdropper. Here...
In this paper, we study the secrecy outage probability (SOP) of an opportunistic relay selection scheme where an optimal relay is selected based on the delayed feedback from the multi-antenna destination. We present a new exact closed-form expression of the SOP, and two kinds of asymptotic form of SOP are further derived to explicitly show secrecy performance. In addition, we show that the SOP can...
Overcurrent relay is an important relay used to protect transmission and distribution feeders, transformer, bus coupler etc. It can be used as main or backup protection relays. The modeling of overcurrent relay and other protection relays is important in the research on the effects of network parameters and configurations on the operation of these relays. This research deal with modeling and simulation...
The communication process of a secure relay system usually has two stages: source to relay, relay to destination. When the source is only equipped with one antenna, the information transmission is not secure during the first stage. In this paper, we propose a novel three-stage scheme to transmit confidential messages in an amplify-and-forward (AF) relay system. In the proposal, during the additional...
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