Research On Some Key Technologies Of Miniaturized Spectrum Monitoring Receiver

With the rapid development of wireless communication technology and the popularity of wireless terminals,the electromagnetic environment of wireless communication becomes more and more complex,and the management of radio spectrum is becoming more and more difficult.Miniaturized spectrum monitoring receiver plays an important role in the monitoring of radio spectrum.Firstly,it is clear that the receiver should have the functions of sweep frequency monitoring and constant frequency monitoring.According to functional requirements,the module of digital signal processing in FPGA is divided into some small modules,and the key technologies used in the main modules are analyzed.Next,the classical time-domain energy detection algorithm is studied in this paper.Considering the uncertainty of noise in the actual environment,the influence of noise uncertainty on detection performance is analyzed,and a double threshold detection algorithm based on noise uncertainty is studied.In order to improve the performance of the detection,a cooperative spectrum sensing algorithm based on multiple threshold is proposed,and the performance of various detection algorithms introduced in this chapter is compared through simulation.In addition,an adaptive time domain energy detection algorithm which can adapt to the changing environment of noise is realized on FPGA.Then,the energy detection algorithm in frequency domain is analyzed and introduced in detail.Considering the constant change of noise in the actual environment,a constant false alarm frequency domain energy detection algorithm under the condition of noise uncertainty is proposed,and some related modules of the frequency domain energy detection algorithm in the FPGA are introduced in detail.Finally,this paper introduces a high-precision time scale generation algorithm,which is used to get accurate time scale for IQ data collected at given frequency.The algorithm combines the long term stability of GPS's PPS and the short term stability of the constant temperature crystal oscillator,and is easy to implement on FPGA.