Patent ID: 8688759
Filing Date: 2014-04-01
Classification: H04L

Abstract:
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 (m 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 P in said processor, computing all R+2 moments and cumulants, wherein for each value of r where r equals 3 to (R plus 2); if |c if |c wherein if |c if |c P in a classifier, classifying each segment as belonging to Class Signal or Class Noise; assigning said data sample segment to Class Signal if P assigning said data sample segment to Class Noise if P in said processor, identifying said at least one signal.