(This article describes the WiMAX protocol reference model, analyzes the main properties of the WiMAX physical layer, gives five implementation methods of the WiMAX physical layer, and finally briefly introduces TiE cross-frequency division multiplexing (OFDM), positive The working principle and advantages and disadvantages of cross frequency division multiple access (OFDMA), hybrid automatic request retransmission (HARQ) and adaptive modulation coding (AMC))