Dynamic Fractional Frequency Reuse (DFFR) with AMC and Random Access in WiMAX System

• Published in: Wireless personal communications 2013-02, Vol.68 (4), p.1871-1881
• Main Authors: Mohades, Zohreh, Tabataba Vakili, Vahid, Razavizadeh, S. Mohammad, Abbasi-Moghadam, Dariush
• Format: Article
• Language: English
• Subjects: Access methods and protocols, osi model; Applied sciences; Coding, codes; Communications Engineering; Computer Communication Networks; Computer science; control theory; systems; Computer systems and distributed systems. User interface; Dynamical systems; Dynamics; Engineering; Equipments and installations; Exact sciences and technology; Frequency reuse; Information, signal and communications theory; Interoperability; Mobile radiocommunication systems; Modulation; Networks; Radiocommunications; Random access; Signal and communications theory; Signal,Image and Speech Processing; Software; Subcarriers; Telecommunications; Telecommunications and information theory; Teleprocessing networks. Isdn; Wireless communication
• ISSN: 0929-6212; 1572-834X
• DOI: 10.1007/s11277-012-0553-2

In this paper; dynamical resource allocation scheme is proposed to improve throughput and fairness in the modern broadband wireless systems such as IEEE 802.16 Worldwide Interoperability for Microwave Access. To assign the subcarriers to users, dynamic fractional frequency reuse is used. In dynamic fractional frequency reuse, each cell is partitioned into two regions, one called super region and another called regular region. Regular region is divided into 3 parts which correspond to the three sectors. In this method, a utility function is firstly used for the subcarrier allocation to the geographical regions and then opportunistic scheduling is applied for the assignment subcarriers to users in each cell. In order to increase the throughput of the system, adaptive modulation and coding techniques are used. Using dynamic fractional frequency reuse reduces fairness among users of a cell. Therefore a random access sub-band is applied to improve the fairness of the system.