A threshold based opportunistic relaying cooperative communication protocol has been analysed in this thesis. The relay is selected opportunistically to maximize the end-to-end signal to noise ratio received at the destination. The relay selection may be proactive and reactive. The underlying communication protocol at relay is decode and forward cooperation. At destination Maximal Ratio Combini...

We propose composite decode-forward (DF) schemes for the two-way relay channel in both the fulland half-duplex modes by combining coherent relaying, independent relaying and partial relaying strategies. For the full-duplex mode, the relay partially decodes each user’s information in each block and forwards this partial information coherently with the source user to the destination user in the n...

In this paper, we investigate the performance of a single-relay cooperative wireless communication system with implementation of Orthogonal Frequency division multiplexing technique under Amplifyand-Forward (AAF) and Decode-and-Forward (DAF) relaying protocols on color image transmission. The system under investigation incorporates four conventional signal combining schemes such as Equal Ratio ...

In this study, the authors propose two schemes to enhance the spectral efficiency of the decode-and-forward adaptive relaying with adaptive modulation. The first scheme, called the minimum error rate scheme, uses cooperative transmission all the time to achieve transmit diversity whereas the second scheme, called the maximum spectral efficiency scheme, tries to avoid cooperative transmission if...

This paper examines the information theoretic metric of outage probability for a decode-and-forward (DF) based asymmetric two-way relay transmission (i.e. the two source terminals have different target rates). We first characterize the achievable rate region of a conventional three-node network. After that the conventional three-node scenario is analyzed in terms of outage probability and the c...

This paper compares the performance of a decode and forward relay assisted wireless uplink with direct wireless uplink in the presence of rayleigh fading where source is equipped with single transmit antenna (Tx), relay is equipped with multiple transmit and receive antennas (Rx), and destination has multiple receive antennas. Data are modulated using QPSK or 16 QAM or 64 QAM modulator at sourc...

The Multiple-access Relay Channel (MARC) has been considered as a promising technique in next generation wireless communication networks. In this work, we study a Network Coding based Multiaccess Relay Channel (NC-MARC) where a decode-and-forward relaying and a static XOR network coding are considered for the one-way relaying system. The system consists of two transmitters communicating with a ...

We investigate fundamental characteristics of cooperative transmission in terms of power efficiency. To do this, we first propose an optimal power allocation method for wireless cooperative networks with Rayleigh fading. By introducing the concept of “cooperative region”, we then evaluate the average power efficiency which is defined as the ratio of total consumed transmit power with cooperatio...

Cooperative Diversity can be used by wireless nodes to take the benefit of broadcast nature and inherent spatial diversity of wireless channel to relay messages for each others. This helps to propagate redundant signals over multiple paths, which can be used to combat the channel noise and fading effects. We investigate the use of packet combining in cooperative diversity scenario. In our appro...