In 4G technology especially LTE relaying and orthogonal frequency division multiple access (OFDMA) are widely accepted techniques in downlink. To obtain ubiquitous coverage with high data rate to user terminals even in difficult channel conditions (e.g. cell edge) a centralized RRM algorithm has been proposed for cellular fixed relay networks in OFDMA networks. The proposed method provides the ...

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...

Time Division Multiple Access (TDMA) amplify and forward based protocols have been investigated previously by various researchers. However, the gap is still there to investigate the performance of these protocols using inter-relay communication in order to improve the diversity order at destination over Rician fading channel. Therefore, the aim of this paper is to propose TDMA based amplify and...

In this paper, we propose a robust relay precoder in the multiple operator relay sharing system, where multiple base stations transmit to their target user terminals simultaneously with the assistance of an amplify-and-forward relay. The base stations and the user terminals are equipped with single antennas while the relay employs multiple antennas. The channel state information at the relay is...

We discuss secure transmission via an untrusted relay when we have a multiple access phase from two nodes to the and broadcast nodes. To realize security, construct code that securely transmits modulo sum of messages channel. In this code, cannot obtain any information with respect message each node, can decode only modulo-sum Our is constructed by simple combination existing linear universal2 ...

Fixed Broadband Wireless Access (FBWA) technology is designed to serve as a wireless DSL replacement to provide broadband Internet access in underserved areas where no other access technology exists. Due to the enormousness of the target service area, relay equipment play an important role in such networks, and the installation and maintenance cost of the network is directly proportional to the...

Efficient utilisation of bandwidth and high data rates have a great impact on the performance of ad hoc wireless networks. The use of cooperative diversity, where neighbouring stations may act as relay nodes to transfer the source data to the desired destination node through an independent relay channel, has shown to provide diversity gain and consequently improve the achievable bit rate. Howev...

A multiple access relay channel (MARC) is considered in which an analogue-like network coding is implemented in the relay node. This analogue coding is a simple addition of the received signals at the relay node. Using “nulling detection” structure employed in V-BLAST receiver, we propose a detection scheme in the destination which is able to provide a diversity order of two for all users. We a...

Channel access delay in a wireless multi-hop ad hoc network is the major source of delay while considering end-to-end delay. In this work, end-to-end delay is analysed considering silent relay nodes and effect of network parameters like node density and throughput. Given network parameter requirements and bound on end-to-end delay, optimal ranges of transmission radius and channel access probab...