Relay Selection Scheme for Improved Performance in the Wireless Communication Systems Based on OFDM

Author(s):  
Sang-Young KIM ◽  
Won-Chang KIM ◽  
Hyoung-Kyu SONG
Author(s):  
Essam Saleh Altubaishi

<span>Relay selection strategy under maximum-signal-to-noise ratio (MAX-SNR) criterion was proven to maximize performance but at the expense of losing fairness among the cooperative relays. In this work, the effect of controlling the MAX-SNR criterion on the spectral efficiency of cooperative wireless communication system with adaptive modulation is investigated. Specifically, the probability density function (PDF) of the end-to-end SNR for the considered system is derived when the controlled selection criterion is considered. Base on that PDF, the average spectral efficiency is then derived and investigated. The results show how the spectral efficiency of the system deteriorates as controlling the selection of a relay. Furthermore, the results of Monte Carlo simulation validate the derived expression.</span>


2018 ◽  
Vol 8 (10) ◽  
pp. 1747 ◽  
Author(s):  
Won-Chang Kim ◽  
Min-Jae Paek ◽  
Hyoung-Kyu Song

Recently, wireless communication systems use a multi-hop transmission scheme using a relay to expand the cell coverage of the system. The multi-hop transmission scheme can expand the cell coverage of wireless communication systems. However, if an appropriate relay is not selected, errors generated during signal processing in the relay are transmitted to the receiver. Therefore, a relay selection scheme is essential for reliable multi-hop transmission. This paper proposes a relay selection scheme for reliable multi-hop transmission in a multi user-multiple input multiple output (MU-MIMO) system. The proposed relay selection scheme uses a MIMO channel matrix between the transmitter and relays to select an appropriate relay. The proposed relay selection scheme obtains the singular values of the MIMO channel matrix using the singular value decomposition (SVD). Then, the sum of the singular values is calculated, and the relay having the largest value is selected. Therefore, in the proposed relay selection scheme, although the transmitter only knows the channel information between the transmitter and relays, the transmitter can select an appropriate relay for reliable multi-hop transmission.


2017 ◽  
Vol 735 ◽  
pp. 194-198 ◽  
Author(s):  
Nishu Gupta ◽  
Zain Hashim ◽  
K.M. Gupta

In the last decade, there have been immense technological developments throughout the world leading to much advancement in the technologies used in wireless communication systems. Massive ongoing research at nanometer length is set to meet the rising demand of the communication industry. So nanoscale materials and devices will play a major role in intelligent communication system. In this paper, we envisage the current and future applications of nanoscale materials and devices for wireless communication systems. It discusses about novel materials and devices that are being designed to provide enhanced and improved quality of service in terms of long range communication, improved performance, less power consumption, smaller size, energy efficient and robustness. We harness the properties and applications of materials at nanoscale dimensions by integrating them with the current technological requirements in terms of extremely high speed, intelligence, large capacity and swift interconnections. Such materials and devices would certainly leverage the future direction of research in wireless communication systems.


Sign in / Sign up

Export Citation Format

Share Document