Energy detection method for restraining direct current bias

Abstract

The invention discloses an energy detection method for restraining direct current bias. A sensor node is used for performing sampling on signals of a monitoring channel, sampled signals are obtained, then, difference operation is performed on signals of two adjacent sampling points in the sampled signals, a differential signal of the signals of the two adjacent sampling points in the sampled signals is obtained, then the total energy of all the differential signals is calculated, finally, the total energy of all the differential signals is compared with a judgment threshold, whether a user is authorized with the signals in the monitoring channel to achieve spectrum sensing or not is judged, and the spectrum sensing performance is high. In addition, due to the fact that when the judgment threshold is calculated, only noise power and false alarm probability need to be known, power of the direct current bias does not need to be known, in this way, when the power of the direct current bias is increased, the spectrum sensing performance can not be reduced, but when the power of the direct current bias is larger than one fourth of the noise power, the method has the better spectrum sensing performance compared with an existing energy detection method.

Description

technical field [0001] The invention relates to a spectrum sensing technology in a cognitive radio system, in particular to an energy detection method for suppressing DC bias. Background technique [0002] With the emergence of a large number of mobile devices such as smart phones, people's demand for wireless data traffic is increasing. The increase of wireless data traffic must be supported by a large amount of spectrum bandwidth. However, the spectrum resources available for wireless communication are limited in practice. After the rapid development of wireless communication in recent decades, most of these available spectrum resources have been allocated to specific authorized users. That is to say, even if these spectrum resources are idle, unlicensed users cannot use them, resulting in a large number of unlicensed users competing for a small number of unlicensed frequency band resources. Various phenomena indicate that the current spectrum resources are becoming more...

AI Technical Summary

Problems solved by technology

In actual situations, there is a DC offset in the receiver (DC offset is generated by the self-mixing of the local oscillator signal during the down-conversion process of the RF signal), and the DC offset will reduce the spectrum sensing performance of the energy detection method, and Urkowitz et al. The proposed energy detection method does not consider and solve the DC bias problem, resulting in its poor spectrum sensing performance

Images