Spectrum Sensing Energy Detection Technology Based On The Characteristic Of Noise Estimation

With the rapid development of wireless communication technology, a variety of new standards, new technologies emerge in large numbers, resulting in a demand for radio spectrum resources. So, wireless spectrum resource constraints phenomenon becomes more prominent. Cognitive radio technology uses a more flexible way of dynamic spectrum access, so it greatly improves the spectrum utilization and resolves the spectrum scarcity problem which is caused by a fixed spectrum allocation policy. It not only provides a new wireless communications technology, but also more suitable to the current spectrum resource management strategies and wireless communication systems, which is considered to meet the broadband wireless communications, and will become an important part of the future communication network.Spectrum sensing technology, as a key technology of cognitive radio, aims to find out the spectrum hole. It makes the the unauthorized user to access to the spectrum assigned to the authorized users without affecting the authorized user’s communication. At present, people have done a lot of research on narrow-band spectrum sensing, however, the perception of narrow-band spectrum sensing is limited. Broadband spectrum sensing can detect multiple channels simultaneously, which greatly improves the cognitive radio spectrum sensing ability and makes a more flexible use of cognitive radio spectrum resources, compared to the narrowband spectrum sensing.This paper mainly studies the broadband spectrum sensing of cognitive radio technology, and its research points and innovations are mainly as follows. Without the priori information of interference system, it studys the wideband iterative spectrum sensing algorithm and presents the detection model of wideband signals; In practice, accurate noise estimation is difficult to be achieved because of low SNR, which results in a large deviation between the iterative convergence threshold and the optimal decision threshold, and then causes a deterioration in detection performance. To address these issues, an improved iterative detection algorithm is proposed in this paper; It studys the problem of threshold selection of broadband energy detection algorithm with the detection performance constraints, and gives the threshold selection criteria of broadband energy detection algorithm with the detection performance constraints; Finally, this paper presents a wideband sampling model with different SNRs in various frequency bands, and then it proposes an improved wideband energy detection algorithm based on the frequency correlation of the authorized signals.