Scheduling Algorithm Research For LTE System

With the development of the personal communications technology in the past 20 years, the global wireless communication's users have exceeded 1.8 billion, and their needs are rapidly transferring to packet data services. Users need urgently the birth of the network whose transmission speed is faster, delay is even shorter, band is wider, and operating costs is less.First of all, this article describes the basic framework of the LTE system, especially the MAC protocol, including the MAC sub-layer functions, the logical channel and the MAC PDU format. Then it discusses the classic scheduling algorithms.Secondly, due to the fact that the frequency reuse factor in LTE-FDD systems is 1, this paper presents an inter-cell interference coordinate(ICIC) algorithm. The cell is divided into two regions, the edge and central region. At the edge region the frequency reuse factor is 3, and at the central region the frequency reuse factor is 1.Finally, this article researchs the joint sub-type scheduling algorithm based on ICIC. The algorithm uses a sub-time period scheduling strategy according to the network services in a time window. When MAC scheduler schedules some users, if the current cell has switched on ICIC, the users at the cell center will be scheduled preferentially in the center band, and then the users of the cell edge will be scheduled preferentially in the edge band. The system-level simulation results show the performance of the scheduling algorithm satisfies the 3GPP standards.