Resources Contact Us Home
Browse by: INVENTOR PATENT HOLDER PATENT NUMBER DATE
 
 
Method and apparatus for decoding two frequency (f/sf) data signals










Image Number 10 for United States Patent #5298897.

A two-frequency data signal, also known as a biphase or F/2F signal, is accurately decoded by sampling the signal and digitizing the samples to provide a series of digital values representing the signal. An intelligent digital filter manipulates the digital values to decode the signal, by detecting the peaks in the sampled signal and decoding the signal by analyzing the location and amplitudes of the peaks. Only peaks which are outside a guard band may be detected. If the signal cannot be properly decoded with a wide guard band, the guard band may be repeatedly narrowed, until a minimum guard band is reached. Bits are identified by comparing the displacements between peaks to a bit cell width. An even number of displacements indicates a `0` bit, and an odd number of displacements indicates a `1` bit. After decoding, the bits are converted into bytes. Parity and longitudinal redundancy code checks are used to correct bad bits. During decoding, many indications of a degraded signal may be obtained. If a degraded signal is indicated, the host computer is notified, even though the signal was properly read. Card replacement can then be initiated at the first signs of signal degradation, before the data signal becomes unreadable.








 
 
  Recently Added Patents
Apparatus and method for foreground detection
Luminescent nanosheets, and fluorescent illuminators, solar cells and color displays utilizing the same as well as nanosheet paints
Image processing system, image processing method and program for image processing
Method and apparatus for using service capability information for user plane location
Method and apparatus for receiving signals in a MIMO system with multiple channel encoders
Mobile terminal apparatus, radio base station apparatus and radio communication method
RFID device using single antenna for multiple resonant frequency ranges
  Randomly Featured Patents
Optoelectric sensor and converter
Liquid crystal display having particular spacer
Quick release chuck device for saw blades
Developing frame for connection with a toner frame wherein a toner application roller crosses a connecting surface of the frames
Locking arrangement for a fluid insertion connection
Combination method for treating diseases caused by cytokine-mediated toxicity
Apparatus for culturing organism and method of culturing organism
Bicycle brake pad toe-out adjusting tool
Ceiling light with an oblong light housing
Heat sink bracket for powered loudspeaker