Sunday, 29 December 2013

DIGITAL COMMUNICATION


DIGITAL COMMUNICATION

  • 1.      The codes developed during the four decades after hamming were definitely achieving practically Error-Free communication
  • 2.      The information sources most of in the nature are analog in nature
  • 3.      The communication channel has a finite Band Width
  • 4.      Geometric representation of signals, which greatly simplifies Signal Detection process
  • 5.      Channels such as under water acoustic channels are molded as Linear Time Variant Filter channels
  • 6.      Gaussian Distribution is used in the various fields of science and engineering
  • 7.      The conversion of analog form of signal to discrete form takes place in Quantiser
  • 8.      Crest Factor describes how strong the signal peak value is with respect to its RMS value
  • 9.      In Adaptive PCM the efficiency can be further improved by allowing the system to adapt to the slowly time varying stastics
  • 10.  Coding can’t generate additional information nor it destroy exisisting information
  • 11.  Huffman code was generated by American scientist D.A.Huffman in 1952
  • 12.  Huffman or Shannon-Fano codes which belongs to the class of  Fixed to Variable Length Codes
  • 13.  Information capacity theorem is also referred as Hartley-Shannon Law
  • 14.  If the weights remain fixed during the transmission of the data the equalization is Preset

  • 15.  Power eefficency of a coherent detection is Optimum

0 comments:

Post a comment