Resource allocation in next generation cellular networks
Date of Issue2014
School of Electrical and Electronic Engineering
Network Technology Research Centre
As cellular services become deeply rooted in people’s daily life and more multimedia services are offered to larger audience, the access demand for high data rate is growing more rapidly than ever. Such demands are to be met with new wireless network technologies. This thesis explored resource allocation schemes under the scope of two different network structures, Time-Division Duplex Code-Division Multiple Access (TDD- CDMA) and Orthogonal Frequency Division Multiple Access (OFDMA). First phase of this thesis studied Multi-hop Cellular Networks (MCNs) under the structure of TDD-CDMA in measurements of both system performance and energy consumption. Two new resource allocation schemes, Multi-Medium MAC with Retransmission (mmMAC/RT) and Opportunistic MAC (OMAC), were proposed and showed significant improvement over traditional Packet Reservation Multiple Access (PRMA) and baseline protocol Multi-hop Multiple Access Control (mMAC). Then the energy consumption of different single and multi-hop time slot allocation schemes was examined. Furthermore, an Opportunistic Relay Station (ORS) selection scheme was proposed and studied. The analysis led to a new half-fixed RS selection protocol and simulation proved the new protocol’s ability to minimize energy consumption under various traffic conditions. Second phase of this project focused on OFDMA networks as it has been selected for future release of 3GPP Long Term Evolution (LTE). The channel characteristics of frequency selective Rayleigh fading channels in OFDMA networks were first studied and a simulation channel model was proposed. An Ordered Interference-Aware Resource (OIAR) allocation scheme was then proposed to take advantage of frequency and user diversity in such networks. Simulation results proved its ability to outperform the random resource allocation scheme. Device-to-Device (D2D) communication was also introduced to cellular networks for higher utilization of radio spectrum. An improved OIAR protocol was adapted for D2D users and different settings have been discussed. The D2D communication underlaying cellular network was proved by simulation to provide higher capacity with such interference- aware resource allocation scheme.
DRNTU::Engineering::Electrical and electronic engineering::Wireless communication systems