By taking a variety of realistic hardware imperfections into consideration, we propose an optimal power allocation (OPA) strategy to maximize the instantaneous secrecy rate of a cooperative wireless network comprised of a source, a destination and an untrusted amplify-and-forward (AF) relay. We assume that either the source or the destination is equipped with a large-scale multiple antennas (LS...

An amplify-and-forward (AF) wireless relay network consisting of a one-source-one-destination node pair and cooperative multiple N relay nodes is proposed in three adverse wireless communication environments, i.e., jamming, node geometry, and channel uncertainty. Based on the minimum mean square error (MMSE) criterion, the optimal amplifying relay matrix in three adverse wireless environments w...

Secured communications in the presence of eavesdropper node is grave for the successful operations in the wireless relay networks. In the proposed work, choose two hop wireless relay networks to enhance security against the eavesdropper node. This paper considers four node networks, they are one source, and three decode and forward relay, one destination and one eavesdropper node. To transmit t...

The reliability and transmission distance are generally limited for the wireless communications due to the severe channel fading. As an effective way to resist the channel fading, cooperative relaying is usually adopted in wireless networks where neighbouring nodes act as relays to help the transmission between the source and the destination. Most research works simply regard these cooperative ...

Cooperative communications is obviously an evolution in wireless networks due to its noticeable advantages such as increasing the coverage as well as combating fading and shadowing effects. However, the broadcast characteristic of a wireless medium which is exploited in cooperative communications leads to a variety of security vulnerabilities. As cooperative communication networks are globally ...

Physical layer security has attracted substantial research interests in recent years. The introduction of cooperative jamming (CJ) into physical layer security can improve transmission security through generating jamming signals with the assistance of external helpers. In this paper, we study robust beamforming design for multiple-input single-output (MISO) wiretap channels under CJ by exploiti...

A new defense mechanism for different jamming attack on Wireless Sensor Network (WSN) based on ant system it is introduced. The artificial sensitive ants react on network attacks in particular based on their sensitivity level. The information is re-directed from the attacked node to its appropriate destination node. It is analyzed how are detected and isolated the jamming attacks with mobile ag...

Currently deployed WLAN network use cooperative spectrum sharing and is prone to jamming based denial of service attack. In this article we propose a model to avoid jamming that use decentralized channel hopping algorithm. Upon detection of jamming, the network switches its channel of operation in accordance with pseudo-random sequence based rendezvous. We develop a testbed to evaluate the feas...

In this article, we investigated the secrecy performance of a three-hop relay network system with Power Splitting (PS) and Energy Harvesting (EH). presence one eavesdropper, signal is transferred from source to destination help relay. The transmits in full-duplex (FD) mood, jamming transfer signals destination. employ Time Switching (TS) (EH) techniques obtain power beacon. study, compared Secr...