Resources Contact Us Home
Browse by: INVENTOR PATENT HOLDER PATENT NUMBER DATE
 
 
Methods and apparatus for encoding information in a signal by spectral notch modulation










Image Number 5 for United States Patent #7746939.

A spectral notch modulation technique for encoding information in a signal involves transforming the signal into the frequency domain via a fast Fourier transform (FFT) of length N, such that the signal is represented by N frequency bins, selectively nulling M of the N frequency bins, where nulled combinations of M frequency bins respectively correspond to encoded information bits, transforming the selectively nulled signal to the time domain via an inverse FFT, and transmitting the selectively nulled signal. At the receiving end, the signal is demodulated to recover the encoded information by transforming the signal into the frequency domain via a fast Fourier transform (FFT) of length N, identifying the set of M nulled frequency bins among the N frequency bins, and converting the set of M nulled frequency bins to corresponding information bits.








 
 
  Recently Added Patents
System and method for content delivery
Liquid formulations of carboxamide arthropodicides
Lighting apparatus
Prevention and treatment of oxidative stress disorders by gluthathione and phase II detoxification enzymes
System and method for providing radio communication in a land mobile radio system
Image processing apparatus and image processing method
Valved, microwell cell-culture device and method
  Randomly Featured Patents
Weatherstrip with releasable protective covering
Lawn mower control device
Heterostructure thermionic coolers
Planar oxygen sensor
Re-enterable split splice housing with flexible locking strip
Semiconductor devices and methods for fabricating the same
Heating fan
Method for reducing material containing metal oxide in solid phase
Child seat monitoring system and method for determining a type of child seat
Storage arrangement for machine tools