Performance Evaluation of Frequency Planning in a Novel Cellular Architecture Based on Sector Relay
ABSTRACT To avoid inter-cell interference effectively and to improve the performance of cell-edge users, a novel cellular architecture, termed Cellular Architecture Based on Sector Relay (CASR), is proposed in this paper, and two frequency planning schemes based on CASR are investigated. In CASR, fixed relays equipped with directional antennas are located at the vertex of the hexagonal cell for sectorization, thus each relay can be shared by three cells. The two frequency planning schemes are designed for different situations, one of which focuses more on the performance of cell one-hop users and the other one focuses on the performance balance between one-hop users and two-hop users. Interference analysis and performance evaluation are implemented for both one-hop users and two-hop users. System-level simulation in multi-cell and multi-user environment shows that compared with the existing cellular relay cell architecture, the proposed CASR combined with the two frequency planning schemes yield higher cell spectral efficiency. Moreover, the performance of cell-edge users is significantly improved.
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ABSTRACT: This paper investigates the issue of frequency planning for cellular system enhanced with two-hop fixed relay nodes (FRNs). Unlike most papers focused on FRN enhanced cellular system, we assume that there is no performance enhancing techniques deployed on the BS-FRNs links. In particular, we propose two frequency planning schemes following the principle of reuse partitioning, and compare, under the assumption that BS communicates with FRNs via non-line-of-sight (NLOS) links, the system performance between our schemes, the case when the channel-borrowing based frequency planning scheme in  is employed, and the conventional system without relaying. It is demonstrated that our proposed schemes can improve the quality of service for mobile terminals located near cell boundaries and can provide remarkably better performance over the frequency planning in . Our studies also show that to fully exploit the potentials of FRN enhanced cellular system some performance enhancing techniques on the BS-FRNs links seem to be indispensable.Proceedings of the 64th IEEE Vehicular Technology Conference, VTC Fall 2006, 25-28 September 2006, Montréal, Québec, Canada; 01/2006
Conference Proceeding: Spectral Efficient Frequency Allocation Scheme in Multihop Cellular Network[show abstract] [hide abstract]
ABSTRACT: Radio frequency allocation is of great importance in the multihop cellular network, because some extra resources (frequency or time slot) seem to be allocated to the relay station. Generally, the tradeoff must be made between the frequency reuse factor and the inter-cell interferences during establishing frequency allocation scheme. A "pre-configured and fixed (PreF)" frequency allocation scheme has been proposed in . In this paper, the concept of "soft frequency reuse (SFR)" in  is first borrowed, and applied to the multihop cellular network. After that, the improvement is made to the SFR scheme, and a more efficient "modified SFR (MSFR)" frequency allocation scheme is proposed. Through the simulations, it is demonstrated that, almost the same cell throughput can be achieved in the PreF and SFR schemes for the uniform traffic distribution, and the MSFR scheme can provide nearly twice cell throughput as large as that in the aforementioned two schemes. Moreover, the SFR and MSFR schemes both outperform the PreF scheme for the non-uniform traffic distribution because of the support to dynamic frequency resource allocation in the proposed schemes.Vehicular Technology Conference, 2007. VTC-2007 Fall. 2007 IEEE 66th; 11/2007
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ABSTRACT: For the next generation wireless communication systems, inter-cell interference (ICI) is the main source of performance degradation in mobile stations, especially, cell-edge mobile stations. This paper presents a novel orthogonal resource allocation algorithm (ORAA) for our proposed system architecture, termed the OFDMA-based cellular wireless system architecture using relays (OCWSAR). By using relays to cover the cell-edge areas and a robust algorithm with priority resource allocation, the ICI of the system is significantly reduced, while the sector frequency reuse factor is maintained at 1. A system-level simulator is developed in a multi-cell/multi-user environment, where the effect of the proposed ORAA can be evaluated precisely in the presence of inter-cell interference (ICI). Furthermore, the simulation results assure that the new system architecture with the associated algorithm yield higher SINR and data throughput for cell-edge users.Consumer Communications and Networking Conference, 2008. CCNC 2008. 5th IEEE; 02/2008