Research On Key Technologies Of Uplink Power Control For Wimax System

WiMAX which means Worldwide Interoperability for Microwave Access, is a new Broadband Wireless Access technology. WiMAX can provide higher speed of Internet access and wider region of wireless access. After the WiMAX taking part into 3rd-generation standand, the WiMAX become more popular in communcation field, and WiMAX technology is researched and applied extensively.The uplink power control is the key technique in wireless communication system, which can keep wireless communication system working steadily. Due to the limitation of frequency spectrum, the frequency reuse to enhance the utilization ratio of frequency spectrum. The Co-channel interference which comes form frequency reuse will affect the whole system's communcation quality and capacity. So it is necessary to use power control technique to restrain Co-channel interference and ensure the communication quality. The research target of my study project is to find suitable uplink power control algorithm working in WiMAX embedded user device and design the circuit for uplink power control.According to IEEE802.16 protocol and power control theory of traditional wireless communication, in terms of open-loop and close-loop, the WiMAX uplink open-loop power control algorithm and close-loop power control algorithm were put. And a game theory based WiMAX uplink power control algorithm was put, inorder to expedite the close-loop algorithm's convergence speed. By the deduction and simulation, these three algorithm can both control SS's uplink power and keep uplink SINR to aim. Comparing the open-loop power control algorithm, the close-loop power control algorithm can be used in more occasion and is more precision, which can reflect the uplink status variety. Utilizing the frame format ordered by IEEE802.16 protocol, a WiMAX uplink close-loop power control algorithm with variable step was put, inorder to avoid the traditional fixed step close-loop power control algorithm's flaw. The game theory based WiMAX uplink power control algorithm was put, according to the game relation between co-channel SS in WiMAX system. It can enhance the convergence speed of power control algorithm, and the suitable constringency factor can reach the balance between convergence speed and SS's final uplink power.At last of paper, the realize of WiMAX embedded user device was researched, and the the hardware frame and key circuit were depicted. The paper also analyzed the circuit which supports the uplink power control in WiMAX embedded user device.