Design And Implementation Of PPN-FBMC System's Modulation And Demodulation Based In USRP RIO

In the past few years,orthogonal frequency division multiplexing technique(OFDM)has been widely used in modern wireless communication systems because of its low implementation complexity,strong ability of anti-multipath interference and other advantages.However,traditional OFDM systems exist many problems such as traditional OFDM systems use rectangular filter,resulting in serious leakage of out-of-band spectrum;the introduction of cyclic prefix(CP)sacrifices the spectrum utilization of the systems.In order to solve the defects of OFDM technique,filter bank multicarrier(FBMC)non-orthogonal modulation technology came into being.Filter bank multicarrier with offset quadrature amplitude modulation(OQAM/FBMC)technique is a kind of FBMC modulation technology.OQAM/FBMC systems have many advantages,such as low out-of-band spectrum leakage,high spectrum utilization and so on.So they have been studied by numerous scholars.The research on OQAM/FBMC is mature.However,this kind of system?s complexity is higher as well,making it not easy to implement.OQAM/FBMC technology must design a robust and simple transceiver to remain its key status in 5G.USRP RIO is a computer device used in the development of software-defined radios.Based on the USRP RIO platform,a robust OQAM/FBMC transceiver can be designed to effectively promote the application of OQAM/FBMC technology.The USRP RIO has a DAC chip,an ADC chip,and a radio frequency module.The analog signal processing of the OQAM/FBMC system can be directly configured on the host computer.In addition,the FPGA inside USRP RIO has high-speed parallel processing capabilities,and can make real-time digital signal processing.The primary task of implementing OQAM/FBMC communication system based on USRP RIO platform is to use LabVIEW software to program related communication algorithms.As the core of the USRP RIO platform,LabVIEW software uses the USRP driver to configure the hardware to perform data processing functions.In addition,the modulation and demodulation complexity in the OQAM/FBMC communication system is relatively high,and the hardware algorithm needs to be optimized accordingly.For this reason,this paper implements the OQAM/FBMC modem based on the USRP RIO platform,and further studies the key technologies and algorithm optimization problems.There are two methods of OQAM/FBMC?s implementation,frequency spreading and poly phase network.By theoretically comparing the computational complexity of the two methods,this paper decided to focus on the research of the less complex PPN-FBMC.This thesis first designs the PPN-FBMC system parameters according to 802.11 a protocol,then uses USRP and PC to simulate users and base stations to build the system hardware architecture;then uses LabVIEW software to program the modulation and demodulation algorithm.Eventually,I have finished video coding,modulation,and demodulation and decode in real time on the NI USRP RIO 2943 R,.The paper focuses on the design and implementation of modulation and demodulation,and gives a large number of simulation and verification results.The implementation part divides the entire modulation and demodulation process into several modules,each of which completes separate functions and algorithms.Since the steps of modulation and demodulation are one-to-one,the corresponding modules are introduced together.The implementation process can be divided into the following modules: scrambling and descrambling,channel coding and channel decoding,interleaving and de-interleaving,OQAM modulation and demodulation,IFFT and FFT,PPN,overlap summation and sliding windows,and channel estimation and equalization.The paper introduced each module in detail,including its algorithm principle,design ideas,LabVIEW code screenshots and screenshots of simulation results.After simulating a single module,connect all modules together for debugging and compile the entire project.The number of resources used by the algorithm is analyzed from the compilation results to verify the excellent performance of the PPN modem.