Optionally support AAS and STC. Modulation methods must support BPSK, QPSK, 16QAM and 64QAM, and optionally support 256QAM. When the roll-off factor is 0.25 and the modulation mode is 256QAM, the 20MHz channel bandwidth can provide a transmission rate of up to 100Mb/s. Using broadband wireless access technology, data, Internet, voice, video and multimedia applications can be delivered to commercial and home users. Among them, the broadband wireless metropolitan area network technology (WMAN, Wireless Metropolitan Area Networks) based on the IEEE802.16 series of standards has attracted wide attention because of its advantages in providing high-speed data wireless transmission and even realizing mobile multimedia broadband services.