Simulation And Research Of The OFDMA System Based On IEEE802.16e

Broadband Wireless Access(WiMax) is a significant component of nextcommunication technology, especially in wireless mobile broadband area.802.16e, asthe air standard of wireless access, it has received extensive research recently.Meanwhile its main physical layer technology OFDMA is one of the streamtechnology of4th mobile communication, and hence the research has crucial practicalsignificance.This paper is mainly aimed for the study and simulation of OFDMA ofIEEE802.16e.1. The formulation process and state-of-art of IEEE802.16standards areintroduced, and the principle of OFDM and OFDMA is elaborated, in addition the keytechnology of the physical layer of IEEE802.16e is explained briefly.2. The system model of the uplink and downlink transceiver of OFDMA system isproposed, and the standards of OFDMA physical layer based on IEEE802.16e ispresented, which consists of symbolic structure, TDD frame structure of physical layerand allocation of uplink and downlink channel.3. The transceiver of uplink and downlink of OFDMA system is simulated throughC++. The principle of each basic module in both the forming process of base band intransmitting terminal and the recovery of data in receiving terminal, furthermore thesimulation and analysis are demonstrated; Finally the entire performance of the systemis simulated and analyzed.4. The timing synchronization and Carrier frequency offset estimation of thedownlink of OFDMA is studied. Based on the influence on system performance bytiming synchronization, Carrier frequency offset and sampling clock frequency offset,two algorithm of timing synchronization is proposed that are pseudo-periodicity ofthree-section of Preamble Sequences-Based and Conjugate symmetry-Based, andtherefore CP-Based fractional frequency offset estimation and the polit-Based integerfrequency offset estimation are presented. At last on the basis of the system feature, thesynchronization flow and simulation of downlink of OFDMA are provided.5. Initial ranging of uplink in OFDMA is researched. On the basis of the model ofuplink, Initial ranging is explained, which mainly includes the generation of precisioncode and the search algorithm of precision code in time and frequency domain, and finally simulation and analysis are carried out.