MIMO-OFDM modulation system

Based on the USRP-LW X310 and the RF daughter board UBX-LW 160M, a 4x4 MIMO-OFDM system was successfully built. The system connection block diagram is shown in the following figure:

The system implementation principle is shown in the following figure:

• The host computer performs data spatio-temporal coding and OFDM modulation to generate baseband modulation data;
• The host computer passes the data through a gigabit switch to two USRP-LW X310s for further processing: first digital upconversion, and then through the DAC Transformation, which converts a digital signal into an analog signal;
• The daughter board converts the baseband signal to a specified frequency by upconversion, and then the antenna sends the signal out;
• The antenna at the receiving end receives a signal in the electromagnetic environment,
• The daughter board at the receiving end downconverts the electrical signal, converts the processed signal to analog-to-digital from the ADC in the USRP-LW X310, and then sends it to the FPGA for digital downconversion, and then passes the processed data through the switch Passed to the host computer for further processing;
• The host computer decompresses the signal BYDM, decodes the spatio-temporal encoding, and recovers the baseband data