Relaying technology is likely to bring real progress to the next generation cellular networks due to its capability of boosting the system capacity and coverage. However, despite recent advances in relay deployment, some challenging problems still remain such as radio resource allocation and relay selection. The authors investigate both relay selection and scheduling strategy in order to improv...

Relay networks enhance the system performance by creating cooperative diversity gain and extend communication range by relaying the received signal to other devices. In this paper, the performance of two-relay networks is analyzed by adopting decode-andforward (DF) relaying protocol. The signaling scheme uses partially differential modulation which applies coherent modulation in source-relays l...

The secure wireless communication has been an important field of research. The proposed max-ratio relay selection techniques introduced to security of transmission in buffer aided cooperative wireless network. The data transmitted from source to relay and relay to destination. An eavesdropper can used to intercept the data from source to relay and relay to destination. Assume, data buffer are a...

We determine necessary conditions on the structure of symbol error rate (SER) optimal quantizers for limited feedback beamforming in wireless networks with one transmitter-receiver pair and R parallel amplify-and-forward relays. We call a quantizer codebook “small” if its cardinality is less than R, and “large” otherwise. A “d-codebook” depends on the power constraints and can be optimized acco...

Cooperative communication is one of the latest techniques in wireless communication to form virtual antenna arrays. Cooperative communication is an alternative method for MIMO (Multiple input multiple output) system. This scheme assumes TDMA (Time division multiple access) channel accessing and divides the communication into two phases which includes direct transmission and retransmission by th...

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...

This paper contains the application criteria and coordination process for a proposed overcurrent relay in a radial power system with feed from one or multiple sources. This relay uses independent functions to detect faults and to calculate the operation time. Also this relay uses a time element function that allows it to reduce the time relay operation, enhancing the backup protection. Some of ...