Ashraf AwadElkarim Widaa Ahmed; Ahmed Hamza Ibrahim Makki 33, pp. 71. ING/School of Engineering, 2010.
The User Equipments (UE) nowadays are able to provide various internet applications
and services that raise the demand for high speed data transfer and Quality of Service (QoS).
Accordingly, next generation mobile communication systems driven by these demands are
expected to provide higher data rates and better link quality compared to the existing systems.
Orthogonal Frequency Division Multiple Access (OFDMA) and Single Carrier Frequency
Division Multiple Access (SC-FDMA) are strong multiple access candidates for the uplink of
the International Mobile Telecommunications-Advanced (IMT-Advanced). These multiple
access techniques in combination with other promising technologies such as multi-hops
transmission and Multiple-Input-Multiple-Output (MIMO) will be utilized to reach the
targeted IMT-Advanced system performance.
In this thesis, OFDMA and SC-FDMA are adopted and studied in the uplink of Long
Term Evolution (LTE). Two transmission scenarios are considered, namely the single hop
transmission and the relay assisted transmission (two hops). In addition, a hybrid multiple
access technique that combines the advantages of OFDMA and SC-FDMA in term of low
Peak-to-Average Power Ratio (PAPR) and better link performance (in terms of Symbol Error
Rate (SER)) has been proposed in relay assisted transmission scenario.
Simulation results show that the proposed hybrid technique achieves better end-to-end
link performance in comparison to the pure SC-FDMA technique and maintains the same
PAPR value in access link. In addition, a lower PAPR is achieved compared to OFDMA
case, which is an important merit in the uplink transmission due to the UE’s power resources
constraint (limited battery power).