IPC분류정보
국가/구분 |
United States(US) Patent
등록
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국제특허분류(IPC7판) |
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출원번호 |
US-0644513
(2009-12-22)
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등록번호 |
US-8688759
(2014-04-01)
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발명자
/ 주소 |
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출원인 / 주소 |
- BAE Systems Information and Electronic Systems Integration Inc.
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대리인 / 주소 |
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인용정보 |
피인용 횟수 :
0 인용 특허 :
10 |
초록
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An algorithm system to detect a broad class of signals in Gaussian noise using higher-order statistics. The algorithm system detects a number of different signal types. The signals may be in the base-band or the pass-band, single-carrier or multi-carrier, frequency hopping or non-hopping, broad-puls
An algorithm system to detect a broad class of signals in Gaussian noise using higher-order statistics. The algorithm system detects a number of different signal types. The signals may be in the base-band or the pass-band, single-carrier or multi-carrier, frequency hopping or non-hopping, broad-pulse or narrow-pulse etc. In a typical setting this algorithm system provides an error rate of 3/100 at a signal to noise ratio of 0 dB. This algorithm system gives the time frequency detection ratio that may be used to determine if the detected signal falls in Class Single-Carrier of Class Multi-Carrier. Additionally this algorithm system may be used for a number of different applications such as multiple signal identification, finding the basis functions of the received signal and the like.
대표청구항
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1. A method for implementing a software defined radio for a Spectrum Sensing Function (SSF) for detecting signals in Gaussian noise, wherein Higher Order Statistics (HOS) are applied to segments of received signals in at least one of time and frequency domains comprising the steps of: providing a re
1. A method for implementing a software defined radio for a Spectrum Sensing Function (SSF) for detecting signals in Gaussian noise, wherein Higher Order Statistics (HOS) are applied to segments of received signals in at least one of time and frequency domains comprising the steps of: providing a receiver device of said software defined radio comprising a processor;at an antenna of said receiver device, receiving said received signal comprising a frequency spectrum;selecting a particular portion of said frequency spectrum;in a band pass filter, excluding regions of said frequency spectrum that are outside of said selected portion;in a low noise amplifier, amplifying output of said band pass filter; adjusting amplifier gain for said amplified output of said band pass filter;in a waveform collector, collecting waveforms from said selected portion of said frequency spectrum;in a downconverter, downconverting said collected waveforms to shift a characteristic frequency component of said collected waveforms to a specified frequency;in an analog to digital converter, applying an analog to digital conversion to said downconverted collected waveforms in an analog to digital converter;applying a low pass filter to filter said downconverted collected waveforms;up or down converting on a spectrum of interest of said downconverted collected waveforms to shift a characteristic frequency component of said downconverted collected waveforms to a specified detection frequency, producing second-converted waveforms;sampling said second-converted waveforms to adjust a sampling rate;applying a serial to parallel converter to convert said sampled second-converted waveforms to a stream of time domain segments, each said time domain segment including a plurality of time domain samples;applying a Fast Fourier Transform (FFT) to each said time domain segment to obtain a corresponding frequency domain segment, each of said frequency domain segments including a plurality of frequency domain samples in a Fast Fourier Transform stage;in said processor, detecting at least one signal by processing said segments using Higher Order Statistics; said processing said segments using Higher Order Statistics comprising dividing said data segments into real and imaginary parts, wherein R is a total number of moments (mr—real, mr—imaginary) and cumulants (cr—real, cr—imaginary) of order greater than two available for computation for said real and said imaginary parts of each segment of said data segments respectively;choosing a value for a probability step parameter (δ) between zero and one;setting a Psignal_real and a Psignal_imaginary to 0.5;choosing a value for a fine threshold parameter (γ) greater than zero, wherein said fine threshold parameter γ is used to control a probability of false alarm PFA and a probability of detection PD;in said processor, computing all R+2 moments and cumulants, whereinfor each value of r where r equals 3 to (R plus 2);if |cr—real| is less than γ|m2—real|r/2, then PSignal—real equals PSignal—real minus δ;if |cr—real| is greater than or equal to γ|m2—real|r/2, then PSignal—real equals PSignal—real plus δ; andwherein if |cr—imaginary| is less than γ|m2—imaginary|r/2, then PSignal—imaginary equals PSignal—imaginary minus δ;if |cr—imaginary| is greater than or equal to γ|m2—imaginary|r/2, then PSignal—imaginary equals PSignal—imaginary plus δ; andPSignal equals aPSignal—real plus bPSignal—imaginary, wherein a and b are weight parameter coefficients;in a classifier, classifying each segment as belonging to Class Signal or Class Noise;assigning said data sample segment to Class Signal if Psignal is greater than or equal to 0.5; andassigning said data sample segment to Class Noise if Psignal is less than 0.5 and no signal is detected; andin said processor, identifying said at least one signal. 2. The method of claim 1, comprising the step of: in said processor, processing said at least one signal in said time domain to detect at least one signal. 3. The method of claim 1, comprising the step of: in said processor, processing said at least one signal in said frequency domain to detect at least one signal. 4. The method of claim 1, comprising the step of: in said processor, processing said at least one signal in said time as well as said frequency domains and combining results to detect at least one signal. 5. The method of claim 1 comprising the step of: in said processor, dividing said stream of time domain segments into smaller segments, whereby said Higher Order Statistics (HOS) signal detection is carried out for each of said segments. 6. The method of claim 1, wherein in said processor, results of signal detection in said time and said frequency domains are combined to determine if said data segment belongs to Class Signal or Class Noise; and wherein combining is defined by Psignal equals c Psignal_time plus d Psignal_frequency, where c and d are coefficients such that c plus d equals 1. 7. The method of claim 1 further comprising: in said processor, pre-processing, said preprocessing comprising at least one of filtering, noise whitening, down-conversion, up-conversion, frequency shift, frequency translation, re-sampling, down-sampling, up-sampling, signal conditioning, wherein said preprocessing is applied to said data segments before computing said HOS of said data segments in at least one of said time and said frequency domains, and wherein sequence of said preprocessing is alterable. 8. The system of claim 1, wherein said received signals are in base-band. 9. The system of claim 1, wherein said received signals are in pass-band. 10. The system of claim 1, wherein said received signals are single-carrier. 11. The system of claim 1, wherein said received signals are multi-carrier. 12. The system of claim 1, wherein said received signals are frequency hopping. 13. The system of claim 1, wherein said received signals are non-frequency hopping. 14. The system of claim 1, wherein said received signals are at least one of Direct Sequence Spread Spectrum and Multi-Carrier Spread Spectrum. 15. The system of claim 1, wherein said received signals are non-Gaussian in said time domain. 16. The system of claim 1, wherein said received signals are non-Gaussian in said frequency domain. 17. The method of claim 1, wherein detecting said at least one signal using said higher order statistics further comprises: adjusting said fine threshold parameter (γ); andin said processor, reclassifying said at least one signal. 18. The system of claim 1, wherein one SSF interfaces with at least one of a Spectrum Manager or a Cognitive Engine, said Spectrum Manager or said Cognitive Engine performing at least one of configuring said channel, configuring said sub-band, configuring a waveform, configuring a protocol, and configuring an operating frequency. 19. The system of claim 1, wherein a plurality of SSFs interface with at least one of a Spectrum Manager or a Cognitive Engine, said Spectrum Manager or said Cognitive Engine performing at least one of configuring said channel, configuring said sub-band, configuring a waveform, configuring a protocol, and configuring an operating frequency. 20. The system of claim 1, wherein a plurality of SSFs interface with a plurality of Spectrum Managers or Cognitive Engines, said Spectrum Manager or said Cognitive Engine performing at least one of configuring said channel, configuring said sub-band, configuring a waveform, configuring a protocol, and configuring an operating frequency. 21. The system of claim 1, wherein the decision on whether a signal is detected in said channel or sub-band is used by a Cognitive Engine or a Spectrum Manager to further arrive at a decision on whether said channel or sub-band may be used for communications, said Spectrum Manager or said Cognitive Engine performing at least one of configuring said channel, configuring said sub-band, configuring a waveform, configuring a protocol, and configuring an operating frequency. 22. The system of claim 1, wherein said SSF reports total signal energy in every channel for at least one of a sub-band, a Power Spectral Density (PSD), an Average Channel Power (ACP), a Received Signal Strength Indicator (RSSI), a Carrier to Interference plus Noise Ratio (CINR), or a Field Strength as input to at least one of a Spectrum Manager or a Cognitive Engine to prioritize use of said channel or sub-band, said Spectrum Manager or said Cognitive Engine performing at least one of configuring said channel, configuring said sub-band, configuring a waveform, configuring a protocol, and configuring an operating frequency. 23. The system of claim 22, wherein said channel or said sub-band with lowest PSD, RSSI, or Field Strength is selected for communications. 24. The method of claim 1, comprising: in said processor, choosing a probability step parameter (δ) equal to one-half the inverse of a number of moments and cumulants of order greater than two available for computation of real and imaginary parts of each segment of said received signal. 25. The method of claim 24, comprising: in said processor, choosing a subset of said cumulants for computation of signal detection probabilities. 26. The system of claim 1, wherein Class Signal or Class Noise determination is performed in said frequency domain by computing Psignal_frequency, where Psignal_frequency equals Psignal computed in said frequency domain. 27. The method of claim 1, comprising: in said processor, choosing a subset of cumulants greater than two for computation of signal detection probabilities. 28. The method of claim 1, comprising: in said processor, choosing even ordered cumulants for computation of signal detection probabilities. 29. The method of claim 1, comprising: in said processor, choosing a subset of even ordered cumulants for computation of signal detection probabilities. 30. The system of claim 1, wherein classifying said detected signal into Class Single Carrier or Class Multi Carrier is based on a Time Frequency Detection Ratio. 31. A method for implementing a software defined radio for a spectrum sensing function (SSF) for detecting signals in Gaussian noise, wherein Higher Order Statistics (HOS) are applied to segments of received signals in at least one of time and frequency domains comprising the steps of: providing a receiver device of said software defined radio comprising a processor;receiving from an antenna, an input signal in said receiver device;selecting, in said receiver device, a particular portion of a frequency spectrum of said received input signal;dividing received data sample stream of said particular portion of said frequency spectrum into smaller segments, whereby said HOS signal detection is carried out for each of said segments;in said processor, pre-processing, said preprocessing comprising at least one of filtering, noise whitening, down-conversion, up-conversion, frequency shift, frequency translation, re-sampling, down-sampling, up-sampling, signal conditioning, wherein said preprocessing is applied to said data segments before computing said HOS of said data segments in at least one of said time and said frequency domains, and wherein sequence of said preprocessing is alterable;in a band pass filter, excluding regions of said frequency spectrum that are outside of said selected portion;in a low noise amplifier, amplifying output of said band pass filter;adjusting amplifier gain for said amplified output of said band pass filter;in a waveform collector, collecting waveforms from said selected portion of said frequency spectrum;in a downconverter, downconverting said collected waveforms to shift a characteristic frequency component of said collected waveforms to a specified frequency;in an analog to digital converter, applying an analog to digital conversion to said downconverted collected waveforms in an analog to digital converter;in a low pass filter, filtering said downconverted collected waveforms;up or down converting on a spectrum of interest of said downconverted collected waveforms to shift a characteristic frequency component of said downconverted collected waveforms to a specified detection frequency, producing second-converted waveforms;sampling said second-converted waveforms to adjust a sampling rate;in a serial to parallel converter, converting said sampled second-converted waveforms to a stream of time domain segments, each said time domain segment including a plurality of time domain samples;applying a Fast Fourier Transform (FFT) to said data segments to convert time domain of said data segments into said frequency domain in a Fast Fourier Transform stage;in said processor, detecting at least one signal by processing said segments using Higher Order Statistics, wherein said HOS signal detection is in said time and said frequency domains;dividing said data segments into real and imaginary parts, wherein R is a total number of moments (mr—real, mr—imaginary) and cumulants (cr—real, cr—imaginary) of order greater than two available for computation for said real and said imaginary parts of each segment of said data segments respectively;choosing a value for a probability step parameter (δ) equal to one-half the inverse of a number of moments and cumulants of order greater than two available for computation of real and imaginary parts of each segment of said received signal;choosing a value for a fine threshold parameter (γ) greater than zero, wherein said fine threshold parameter γ is used to control a probability of false alarm PFA and a probability of detection PD;setting a Psignal_real and a Psignal_imaginary to 0.5;in said processor, computing all R+2 moments and cumulants, whereinfor each value of r where R equals 3 to (R plus 2);if |cr—real| is less than γ|m2—real|r/2, then PSignal—real equals PSignal—real minus δ;if |cr—real| is greater than or equal to γ|m2—real|r/2, then PSignal—real equals PSignal—real plus δ; andwherein if |cr—imaginary| is less than γ|m2—imaginary|r/2, then PSignal—imaginary equals PSignal—imaginary minus δ;if |cr—imaginary| is greater than or equal to γ|m2—imaginary|r/2, then PSignal—imaginary equals PSignal—imaginary plus δ; andPSignal equals aPSignal—real plus bPSignal—imaginary, wherein a and b are weight parameter coefficients;assigning said data sample segment to Class Signal if PSignal is greater than or equal to 0.5;assigning said data sample segment to Class Noise if PSignal is less than 0.5 and no signal is detected;adjusting said fine threshold parameter (γ);reclassifying said at least one signal;in a classifier, classifying a segment as belonging to Class Signal or Class Noise, wherein results of said HOS signal detection in said time and said frequency domains are combined to determine if said data segment belongs to Class Signal or Class Noise; andin said processor, identifying said at least one signal. 32. A system for implementing a software defined radio for Spectrum Sensing and signal identification wherein Higher Order Statistics (HOS) are applied to segments of received signals in time and frequency domains comprising: an antenna receiving said received signals;a receiver device comprising a processor receiving said received signals from said antenna;said processor configured to perform the steps of:selecting a particular portion of a frequency spectrum;in a band pass filter, excluding regions of said frequency spectrum that are outside of said selected portion;in a low noise amplifier amplifying output of said band pass filter;adjusting amplifier gain for said amplified output of said band pass filter;in a waveform collector, collecting waveforms from said selected portion of said frequency spectrum;in a downconverter, downconverting said collected waveforms to shift a characteristic frequency component of said collected waveforms to a specified frequency;in an analog to digital converter, applying an analog to digital conversion to said downconverted collected waveforms;in an image rejection first Low Pass (LP) filter, first filtering down-converted signal through said image rejection first Low Pass (LP) filter, wherein an image of said downconverted signal is suppressed producing a first-filtered signal;in an up converter, upconverting said first-filtered signal, wherein a video carrier would be shifted closer to 0 Hertz frequency;in a second filter, filtering said upconverted signal producing a second-filtered signal;in a downsampler, downsampling said second-filtered signal producing a downsampled signal;in a serial-to-parallel converter, converting samples of said downsampled signal from serial to parallel in a serial to parallel converter producing parallel samples;collecting said parallel samples;in a buffer, storing said parallel samples in a buffer producing stored samples;in a Fast Fourier Transform stage, applying a Fast FourierTransform (FFT) to said stored samples to obtain a corresponding frequency domain segment, each of said frequency domain segments including a plurality of frequency domain samples;in said processor, determining higher order moments and cumulants of real and imaginary portions of said stored samples;in said processor, calculating signal probability for each of said frequency domain segment; said calculating signal probability comprising dividing said data segments into real and imaginary parts, wherein R is a total number of moments (mr—real, mr—imaginary) and cumulants (cr—real, cr—imaginary) of order greater than two available for computation for said real and said imaginary parts of each segment of said data segments respectively;choosing a value for a probability step parameter (δ) between zero and one;setting a Psignal_real and a Psignal_imaginary to 0.5;choosing a value for a fine threshold parameter (γ) greater than zero, wherein said fine threshold parameter γ is used to control a probability of false alarm PFA and a probability of detection PD;computing all R+2 moments and cumulants, whereinfor each value of r where r equals 3 to (R plus 2);if |cr—real| is less than γ|m2—real|r/2, then PSignal—real equals PSignal—real minus δ;if |cr—real| is greater than or equal to γ|m2—real|r/2, then PSignal—real equals PSignal—real plus δ; andwherein if |cr—imaginary| is less than γ|m2—imaginary|r/2, then PSignal—imaginary equals PSignal—imaginary minus δ;if |cr—imaginary| is greater than or equal to γ|m2—imaginary|r/2, then PSignal—imaginary equals PSignal—imaginaryplus δ; andPSignal equals aPSignal—real plus bPSignal—imaginary, wherein a and b are weight parameter coefficients;in a classifier, classifying each segment as belonging to Class Signal or Class Noise;in said processor, assigning said data sample segment to Class Signal if PSignal is greater than or equal to 0.5; andin said processor, assigning said data sample segment to Class Noise if PSignal is less than 0.5 and no signal is detected. 33. A method for implementing a software defined radio for classifying a Denial of Service (DoS) signal comprising the steps of: at an antenna of a signal receiver device comprising a processor, receiving an input signal;in said processor, determining a bit error rate degradation of said received signal;in said processor, determining a Carrier to Interference plus Noise Ratio (CINR) of said received signal;in a signal strength measurement stage, determining a Received Signal Strength Indication (RSSI) of said received signal;in said processor, performing signal or noise detection on said received signal using higher order statistics (HOS); said performing signal or noise detection on said received signal using Higher Order Statistics comprising dividing said data segments into real and imaginary parts, wherein R is a total number of moments (mr—real, mr—imaginary) and cumulants (cr—real, cr—imaginary) of order greater than two available for computation for said real and said imaginary parts of each segment of said data segments respectively;in a signal probability calculator, choosing a value for a probability step parameter (δ) between zero and one;setting a Psignal_real and a Psignal_imaginary to 0.5;choosing a value for a fine threshold parameter (γ) greater than zero, wherein said fine threshold parameter γ is used to control a probability of false alarm PFA and a probability of detection PD;in said processor, computing all R+2 moments and cumulants, whereinfor each value of r where r equals 3 to (R plus 2);if |cr—real| is less than γ|m2—real|r/2, then PSignal—real equals PSignal—real minus δ;if |cr—real| is greater than or equal to γ|m2—real|r/2, then PSignal—real equals PSignal—real plus δ; andwherein if |cr—imaginary| is less than γ|m2—imaginary|r/2, then PSignal—imaginary equals PSignal—imaginary minus δ;if |cr—imaginary| is greater than or equal to γ|m2—imaginary|r/2, then PSignal—imaginary equals PSignal—imaginary plus δ; andPSignal equals aPSignal—real plus bPSignal—imaginary, wherein a and b are weight parameter coefficients;in a classifier, classifying each segment as belonging to Class Signal or Class Noise;assigning said data sample segment to Class Signal if Psignal is greater than or equal to 0.5; andassigning said data sample segment to Class Noise if Psignal is less than 0.5 and no signal is detected;thereby detecting time and frequency domain components of said received signal in said processor; andin said processor, identifying Gaussianity of said time and frequency domain components whereby said DoS signal is classified from results of said detecting step. 34. A method for implementing a software defined radio for signal identification comprising the steps of: at an antenna of a receiver device comprising a processor, receiving said received signal comprising a frequency spectrum;selecting a particular portion of said frequency spectrum;in a band pass filter, excluding regions of said frequency spectrum that are outside of said selected portion;in a waveform collector, collecting waveforms from said selected portion of said frequency spectrum;in a downconverter, downconverting said collected waveforms to shift a characteristic frequency component of said collected waveforms to a specified frequency;in an analog to digital converter, applying an analog to digital conversion to said downconverted collected waveforms in an analog to digital converter;in an image rejection first Low Pass (LP) filter, first filtering down-converted signal wherein an image of said downconverted signal is suppressed producing a first-filtered signal;in an up converter, upconverting said first filtered signal, wherein a characteristic frequency component of said signal would be shifted closer to 0 Hertz frequency;in a second filter, second filtering said upconverted signal producing a second-filtered signal;in a downsampler, downsampling said second filtered signal producing a downsampled signal;in a serial-to-parallel converter, converting samples of said downsampled signal from serial to parallel producing parallel samples;collecting said parallel samples;in a buffer, storing said parallel samples, producing stored samples;in a Fast Fourier Transform stage, applying a Fast Fourier Transform (FFT) to said stored samples to obtain a corresponding frequency domain segment, each of said frequency domain segments including a plurality of frequency domain samples;in said processor, determining higher order moments and cumulants of real and imaginary portions of said stored samples;in said processor, calculating signal probability for each of said frequency domain segment; said determining and calculating steps comprising dividing said segments into real and imaginary parts, wherein R is a total number of moments (mr—real, mr—imaginary) and cumulants (cr—real, cr—imaginary) of order greater than two available for computation for said real and said imaginary parts of each segment of said segments respectively;choosing a value for a probability step parameter (δ) equal to one-half the inverse of a number of moments and cumulants of order greater than two available for computation of real and imaginary parts of each segment of said received signal;setting a Psignal_real and a Psignal_imaginary to 0.5;choosing a value for a fine threshold parameter (γ) greater than zero, wherein said fine threshold parameter γ is used to control a probability of false alarm PFA and a probability of detection PD;in said processor, computing all R+2 moments and cumulants, whereinfor each value of r where r equals 3 to (R plus 2);if |cr—real| is less than γ|m2—real|r/2, then PSignal—real equals PSignal—real minus δ;if |cr—real| is greater than or equal to γ|m2—real|r/2, then PSignal—real equals PSignal—real plus δ; andwherein if |cr—imaginary| is less than γ|m2—imaginary|r/2, then PSignal—imaginary equals PSignal—imaginary minus δ;if |cr—imaginary| is greater than or equal to γ|m2—imaginary|r/2, then PSignal—imaginary equals PSignal—imaginary plus δ; andPSignal equals aPSignal—real plus bPSignal—imaginary, wherein a and b are weight parameter coefficients;in a classifier, classifying each segment as belonging to Class Signal or Class Noise;assigning said data sample segment to Class Signal if PSignal is greater than or equal to 0.5; andassigning said data sample segment to Class Noise if PSignal is less than 0.5 and no signal is detected; andin said processor, identifying said at least one signal. 35. The method of claim 34 comprising: in said processor, choosing all cumulants greater than two for computation of signal detection probabilities. 36. The method of claim 34 comprising: in said processor, choosing a subset of cumulants for computation of signal detection probabilities.
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