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Detecting method for cognitive radio wideband frequency spectrum

A cognitive radio and broadband spectrum technology, applied in the field of cognitive radio broadband spectrum detection, can solve the problems such as the inability to effectively divide the authorized signal frequency band and the complexity of the actual environment, so as to overcome the detection problems and improve the robustness.

Inactive Publication Date: 2014-06-25
SHANGHAI NORMAL UNIVERSITY
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  • Abstract
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  • Claims
  • Application Information

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Problems solved by technology

However, the actual environment is complex
For example: the edge of the frequency band can also have no steep changes; moreover, when the signal is heavily affected by noise, the low signal-to-noise ratio (SNR) can lead to many false steep edges in the signal spectrum
Therefore, the traditional wavelet-based broadband spectrum detection technology cannot effectively divide the frequency band occupied by the licensed signal

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  • Detecting method for cognitive radio wideband frequency spectrum
  • Detecting method for cognitive radio wideband frequency spectrum
  • Detecting method for cognitive radio wideband frequency spectrum

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Embodiment Construction

[0036] The present invention will be further described below in conjunction with accompanying drawing and example.

[0037] The specific design steps of a cognitive radio broadband spectrum detection method are as follows:

[0038] 1. Sampling the received signal: Let x(t) be the received continuous time signal, sample the received continuous signal and convert it into a discrete signal, denoted as y(n), n=0, 1,..., N s -1, where N s is the number of sampling points.

[0039] 2. Calculating the power spectral density PSD of the discrete signal as a function of the true frequency.

[0040] 3. Perform L-layer wavelet multi-resolution analysis on the power spectral density PSD to obtain the approximate low-frequency component on the L-th layer, denoted as a(f), where f is proportional to the real frequency dimension.

[0041] 4. Calculate the probability density function PDF of the approximate low frequency component, and design the calculated probability density function PDF...

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Abstract

The invention discloses a detecting method for a cognitive radio wideband frequency spectrum, which comprises the following steps: sampling the received signal, converting the continuous signal to the discrete signal; computing the power spectral density PSD (Power Spectral Density) of the discrete signal; carrying out a small wave multi-resolution analysis of an L layer to the power spectral density PSD to obtain an approximate low frequency component on the L-th layer, wherein the L is not smaller than 1 and is an integer; computing a probability density function PDF (Probability Density Function) of the approximate low frequency component; determining the detection threshold via searching a local minimum point of the probability density function PDF; comparing the approximate low frequency component on the L-th layer with the detection threshold to judge the frequency band range occupied by the authorized signal on a small wave frequency domain; mapping the frequency band occupied by the authorized signal on the small wave frequency domain to a real frequency band; and the mapping relationship is that the real frequency band range is 2L times than the frequency band range on the small wave frequency domain.

Description

technical field [0001] The invention relates to the technical field of cognitive radio broadband spectrum detection methods. Background technique [0002] Since the traditional static spectrum allocation mode has been increasingly unable to meet the development needs of the current society in the field of wireless communication, cognitive radio technology is becoming a frontier topic in the field of wireless communication today. Cognitive radio technology can actively look for holes in the frequency spectrum and opportunistically use the frequency band without affecting licensed users. The proposal of cognitive radio greatly promotes the reasonable application of spectrum maximization. At present, the U.S. government has opened up part of the TV frequency band, and has authorized communication devices with cognitive functions to use this frequency band under reasonable circumstances. [0003] In cognitive radio, spectrum detection technology is the most important. Only by...

Claims

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Application Information

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Patent Type & Authority Patents(China)
IPC IPC(8): H04B17/00H04W24/00H04B17/327
Inventor 黄立辉李莉
Owner SHANGHAI NORMAL UNIVERSITY