Studies in cooperative communication systems over fading channels

• Main Author: Garg, Sameer.
• Other Authors: Teh Kah Chan
• Format: Theses and Dissertations
• Language: English
• Published: 2013
• Subjects: DRNTU::Engineering
• Online Access: http://hdl.handle.net/10356/54904
• Institution: Nanyang Technological University

Spatial diversity in wireless networks can be attained by the use of cooperative transmission. Leveraging spatial diversity enhances the performance of the system, similar to MIMO (Multiple-Input Multiple-Output) technologies, but without the requirement of multiple antennas installed in a single mobile device. In cooperative transmission, mobile devices share their antennas with each other, ' forming an indirect multiple antenna transmitter that provides spatial and transmit diversity to the transmission. In this dissertation, we focus on analysing the performance of cooperative communication systems with single/multiple users under different fading channels with efficient transmission protocols at the relay. First, we analyse a single relay model for a single user using cooperative transmission. To attain cooperative diversity, Maximal Ratio Combining (MRC) scheme has been employed at the destination. We then analyse how the relaying protocols (Decode-Forward and Amplify-Forward) affect the message detection at the destination. Through simulation results, we compare the BER (Bit Error Rate) performance of the cooperative transmission affected by different fading models. Next, we consider multiple users communicating with the same destination in cooperative transmission. Two models, Single Dedicated Relay (SDR) and Single Shared Relay (SSR), are analysed by implementing orthogonal codes for multiple access and detection at the destination. Based on the analysis of the simulation results we achieve, we conclude that the cooperative cooperation performs better than the single transmission from source to destination.