Detecting narrow band interference in wireless networks using spectral analysis

摘要

A method detects narrow band interference in wireless networks by first thresholding each block of samples to produce thresholded samples. The samples are normalized frequency magnitudes obtained from a spectrum of a wireless signal in a channel. Each block of the thresholded samples is summed to produce a thresholded value for each block. Then, thresholded values are autocorrelated to determine whether a bandwidth of the wireless signal is consistent with narrow band interference.

主权项

1. A method for detecting narrow band interference in wireless networks, comprising:
thresholding each block of samples to produce thresholded samples, wherein the samples are normalized frequency magnitudes obtained from a spectrum of a wireless signal in a channel; summing each block of the thresholded samples to produce a thresholded value for each block; and autocorrelating the thresholded values to determine whether a bandwidth of the wireless signal is consistent with narrow band interference, wherein the steps are performed in a processor, wherein the summing produces the thresholded value according toy⁡(n)=∑j=1Nfft⁢⁢(Xj,n-Xthreshold)+,where j indexes the a number of samples in the block n and Nfft is a positive integer, Xj,n are the samples, Xthreshold is the threshold, and an operator (x)+ is defined by(x)+={xx>00x≤0.wherein the autocorrelation is obtained according to
r(m)=E[y(n)y(n+m)], where E[.] is an expectation and m represents a delay at which the auto correlation is evaluated.