Studies On SAD Algorithms And Corresponding Theoretical Values Of Detection Performance Of Amplitude/Phase Modulation Signals

With the rapid development of wireless communication technology,more and more wireless network services are springing up.Because the distribution of spectrum is fixed and the use of spectrum is dynamic,the utilization of spectrum is low and the distribution of spectrum resources is seriously uneven.Signal activity detection(SAD)technology is one of the key technologies of spectrum sensing in cognitive radio.Combining with dynamic spectrum access technology,it can effectively improve the use of spectrum resources,and then improve the spectrum utilization.Amplitude/phase modulation is the main modulation mode of communication signals in large capacity digital communication and satellite communication and other systems.Amplitude/phase modulation SAD is the key technology of cognitive radio spectrum sensing in large capacity digital communication and satellite communication and other systems.In this paper,the SAD algorithms and its theoretical values of detection performance of amplitude/phase modulated signals are studied.The main work of this paper is as follows:(1)This paper summarizes the SAD technology of amplitude/phase modulation signals.This paper reviews the development of SAD technology;Summarizes the research index and research classification of SAD technology;Deeply studies the research status of amplitude/phase modulation signals SAD,points out the shortcomings in the research,and clarifies the purpose of this paper.(2)The classical detection methods,such as energy detection,matched filter detection and likelihood ratio detection,are applied to the problem of amplitude/phase modulated signals SAD;The energy detector(ED),the modified energy detector(MED),the matched filter detector(MFD),the Bayesian detector(BD)and the generalized likelihood ratio detector(GLRD)are obtained for the amplitude/phase modulated signals SAD;A modified matched filter detector(MMFD)algorithm with low computational complexity is designed.By replacing all the reference signals with the key reference signals,the algorithm greatly reduces the computational complexity and achieves the same detection performance as MFD algorithm;The performance of the proposed SAD algorithms is simulated and analyzed.(3)A new method for calculating the probability of missing detection of polygonal decision region in additive white Gaussian noise(AWGN)is designed,and the calculation process is optimized.The theoretical value of detection performance of MMFD to Multiple Phase Shift Keying(MPSK)signals in AWGN is calculated and verified by simulation,the theoretical values of detection performance of MMFD,ED and MED to multiple pulse amplitude modulation(MPAM)signals and multiple quadrature amplitude modulation(MQAM)signals in AWGN are calculated and verified by simulation;The approximate optimal theoretical values of detection performance of SAD algorithm for amplitude/phase modulation signals are summarized.