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
Semiconductor device
Warm air generating apparatus, sheet feeding apparatus, and image forming apparatus including warm air generating apparatus and sheet feeding apparatus
Synchronization of sound generated in binaural hearing system
Vehicle motion control device
Liquid dispensing apparatus
Composition comprising a mixture of dextro- and levo-amphetamines complexed with ion-exchange resin particles to form drug resin particles
Lower set insert with a lower ball seat for a downhole plug
  Randomly Featured Patents
Process of producing calcium-supplemented milk drinks
Illuminated floor mat advertiser
Load support device made of cardboard material that can withstand pressure forces exerted thereon
Gateway
Induction heating, temperature self-regulating
Slip-controlled brake system
Loop bandwidth enhancement technique for a digital PLL and a HF divider that enables this technique
Lubricating oil composition
Material formulation for galvanizing equipment submerged in molten aluminum and aluminum/zinc melts
Apparatus for use in laminating a workpiece