Research On Adaptive Sensing Technology Based On Spectral Correlation

In the past decade,as limited spectrum resources become scarcer,cognitive radio teclhnology emerges as the times require.Spectrum sensing technology is the basis of cognitive radio.This paper mainly studies the application of spectrum sensing in multi-bandwidth signal scenarios.The existing spectrum sensing algorithms have low detection performance in low SNR and multi-bandwidth signal scenarios,and cannot effectively detect signals with different SNRs.Therefore,in order to effectively solve these problems,this paper studies daptive correlation window energy detection technology and adaptive frequency resolution energy detection technology.The main contents and innovations of this paper are:1.An adaptive correlation window energy detection algorithm is proposed.The traditional energy detection algorithm has poor detection ability for low SNR signals.The derivation and simulation show that the optimal spectral correlation ratio and correlation window size can be selected for different SNR signals,which can improve the detection rate of the low SNR signal with the spectrum sensing algorithm.Therefore,the optimal correlation window size and the optimal spectral correlation ratio under different SNR signals are studied,and an adaptive correlation window energy detection algorithm is proposed.The algorithm uses rough resolution sensing for spectrum sensing,and then uses adaptive spectral correlation ratio and correlation window size parameters for fine resolution sensing,which can solve the problem of poor detection performance when detecting low SNR signals.The simulation results verify the detection performance of the adaptive correlation window energy detection algorithm.Under the condition of ensuring the detection performance,the false alarm rate is lower than 5%,and the detection rate is higher than 95%,and the detection of the adaptive correlation window energy detection algorithm is the lowest.The SNR is reduced by about 3 dB compared to the existing algorithm.2.An adaptive frequency resolution energy detection algorithm is proposed.In a multi-bandwidth signal scenario,there are multiple wideband signals with different SNR.The existing algorithm can only detect a single wideband signal,and the detection performance begins to decrease when the SNR is low.Therefore,an improved algorithm is proposed,which combines the optimal spectral correlation ratio,optimal correlation window size and optimal Nt under different SNRs.An adaptive frequency resolution energy detection algorithm is proposed.The algorithm firstly uses the rough resolution to quickly and accurately sense the spectrum,and accurately estimates the SNR of each wideband signal,and then performs fine resolution sensing.In the fine resolution sensing,the corresponding signal is used for different SNR signals.The adaptive spectral correlation ratio and the correlation window size parameter perform energy detection,which solves the problem of poor detection performance in a multi-bandwidth signal scenario.The simulation results show that the lowest detection SNR ratio of the adaptive frequency resolution energy detection algorithm can be reduced by about 2dB compared with the existing algorithm under the condition of ensuring the detection performance.