Research And Design Of High Order QAM Digital Baseband Based On IEEE 802.11ah

IEEE 802.11 is a widely used communication standard.In 2016,the IEEE 802.11 project team released IEEE 802.11 ah,which has multiple access nodes,low power consumption and high coverage,and has great application potential in the Internet of Things.This paper designs IEEE 802.11 ah high-order Quadrature Amplitude Modulation?QAM?digital baseband,and implements IEEE 802.11 ah 1M format?S1G₁M?Single Into Single Out?SISO?Physical Layer Protocol Data Uni?PPDU?transmission and reception based on Orthogonal Frequency Division Multiplexing?OFDM?.The main work of the paper is as follows:For the IEEE 802.11 ah transmitter digital baseband,the scrambling module,coding module,interleaving module,Binary Phase Shift Keying?BPSK?modulation module,64 QAM modulation module,Inverse Fast Fourier Transformation?IFFT?and cyclic prefix module,windowing module are designed and implemented.Among them,a low-complexity hardware implementation method is used for the interleaving expression in the interleaving module.For the IEEE 802.11 ah receiver digital baseband,the frame detection module,carrier frequency offset estimation/compensation module,symbol synchronization module,channel estimation and equalization module,Fast Fourier Transformation?FFT?module,demodulation and deinterleaving module,Viterbi decoding module,descrambling module are designed and implemented.For the demodulation and deinterleaving of the Signal domain,the equal gain combining deinterleaving demodulation design for quadratic repetition is designed.For decoding,a Viterbi decoder that can switch the new code distance calculation method according to different puncturing methods is designed.The test of the digital baseband is completed based on NI virtual instrument technology.Using the Lab VIEW software,the IEEE 802.11 ah digital baseband FPGA VI was designed and compiled,and the host VI for controlling the FPGA VI was designed.With NI PXIe-5646 R RF vector signal transceiver,the FPGA implementation and test of digital baseband is completed.The test results show that the digital baseband designed in this paper realizes the correct transmission of IEEE 802.11 ah PPDU data and meets the design requirements.