Portable RF Transceiver System For Power Wireless Private Network

Within the authorized frequency band of power wireless private network,frequency points are often occupied by unauthorized users and 230 data transmission radio station.In addition,the authorized frequency points of power wireless private network are very discrete,resulting in low spectrum utilization and difficult interference source judgment.In order to comprehensively test the current environment before the construction of the network and provide reliable information for the base station construction,and also improve the spectrum utilization,this thesis designs a portable RF transceiver system for the power wireless private network.In order to realize the portable system of transceiver integration,this thesis selects the integrated bandwidth IC as the RF transceiver,and realizes the information and data interaction between the host computer and FPGA through the PCI bus.The realization method of RF transceiver system is as follows:1.IF signal source is generated by OFDM principle and carrier aggregation technology.IF signal source is modulated and transmitted by AD9361.According to the principle and implementation method of OFDM,an OFDM baseband signal source with 128 ksps sampling rate and 22 k Hz bandwidth is designed.According to the principle of IF transceiver,the implementation structure of IF signal source is designed by using carrier aggregation technology,and the CIC filter is used for up sampling.Finally,the IF signal source with sampling rate of 65.536 Msps and bandwidth of12.8MHz is obtained.AD9361 is selected to modulate IF signal source to RF carrier to transmit,so as to realize the function of RF emission.2.The RF signal is received by AD9361 and analyzed by Digital Channelization and energy detection algorithm.Use the receiving channel of AD9361 to receive the RF signal and convert it into baseband I/Q signal.In order to improve the spectral resolution of baseband signal,the digital channelized structure is used for data processing.The swept frequency bandwidth of Digital Channelization is 229 MHz ±8.192 MHz,which is divided into 10 subchannels.Through the down sampling and filtering of CIC filter and half band filter,the sampling rate of each subchannel is3.2768 MHz.Then the FFT calculation of 32768 points is carried out,and the spectral data with resolution of 100 Hz is obtained.The spectral data is uploaded to the host computer through the PCIe interface for further analysis.The spectrum sensing algorithm is used to determine whether there are authorized signals and interference signals in the bandwidth,and also the occupied frequency point and bandwidth range are given.Through the above analysis of the system requirements,the work completed in this thesis includes the Simulink simulation analysis of related algorithms,FPGA program design,hardware platform construction and system testing.Simulink simulation analysis includes OFDM baseband signal source,IF signal source,digital channelization and spectrum sensing algorithm.FPGA program design includes AD9361 transceiver channel control,digital channelization program design,data transmission of PCIe uplink and downlink and DDR3 read-write control program.The final system test shows that the RF transceiver system designed in this thesis can transmit and receive RF signals according to the requirements,and also can give accurate frequency point information and bandwidth range estimation for interference signals in the LTE230 band.