Next-generation wireless communication with low-complexity low-feedback cooperative-relay tranmission

• Main Author: Ho, Edwin.
• Other Authors: Guan Yong Liang
• Format: Final Year Project
• Language: English
• Published: 2010
• Subjects: DRNTU::Engineering::Electrical and electronic engineering::Wireless communication systems
• Online Access: http://hdl.handle.net/10356/39075
• Institution: Nanyang Technological University

Nowadays mobility is an important aspect in human life. Many people need to communicate with each other and have a free access to information despite the time and location of the individual and information. Wireless communication is needed. In wireless communication, information sent by the source can be misinterpreted by the destination due to the attenuation caused by the interference, fading, propagation loss and etc. The negative effect caused by multipath fading in the wireless transmission can be reduced by introducing a concept of cooperative relay transmission, which results in diversity gain. The best relaying scheme in term of BER performance is MRC-MRT Relaying Scheme. However, it required a tradeoff, which is a high processing complexity and feedback. Therefore, the study of cooperative relay transmission scheme with low-complexity low-feedback and yet still gives a good BER performance is a fertile area of research and will be beneficial. In this report, we propose a new relaying scheme, which is Equal Gain Combining (EGC) Relaying Scheme. We will test and compare this new relaying scheme to other relaying scheme in term of BER performance, processing complexity and feedback requirement by using MATLAB simulation. We also study the signal flow of the all of relaying schemes, so we are able to simulate the BER performance in perfect or estimated channel approach. In addition, we also discuss the algorithm how to estimate the channel and how to calculate and compare the processing complexity and feedback requirement. In conclusion, the study of the EGC Relaying Scheme gives a good result. It has a roughly same BER performance with MRC-MRT Relaying Scheme. Additionally, it also has a low complexity and low feedback requirement. Hence, we are able to reduce the tradeoff to get a roughly the same BER performance but using a lower complexity and lower feedback requirement. Another useful finding is that Selective Relaying Scheme give a better BER performance compared to MRC-MRT Relaying Scheme in high input SNR value with a far lower processing complexity is required. However, the reason behind this result still needs to be researched and studied in the future.