Performance Improvement Using Single Carrier-FDMA in Relay Based LTE Uplink System

Abstract

In this paper, we proposed to install a relay between base station and terminal (or user equipment) in order to improve receiving performance of the downlink transfer mode of the Long Term Evolution (LTE) system, which is the next-generation mobile communication technology standard that has been proceeding in the 3rd General Partnership Project (3GPP). In 3GPP LTE-advanced, hybrid OFDMA/SC-FDMA is recommended for its technological capability to make up for the performance gap between OFDMA and SC-FDMA and to make PAPR more efficient. OFDMA is used in LTE downlink in order to make frequency more efficient and raise cell capacity but OFDM struggles with a high PAPR owing to its use of multi carrier wave. LTE uplink, on the other hand, employs SC-FDMA, which is similar to OFDMA, but makes up for OFDM’s big PAPR in mobile stations where electricity efficiency is critical. We conduct a paper to improve receiving performance having selected OFDMA and SC-FDMA, as the transfer mode of base station and relay based on the distance of the relay that has been installed and location of base station. The paper found SC-FDMA to be better choice in RS when it is closer to BS and OFDMA to be a better choice in RS when the distance between BS and RS is farther. The system’s reception performance improved when the most appropriate transmission method fitting the circumstances was used in the middle between BS and MS.