07/16/18

Modulation:

• Change amplitude or frequency
• Transmit square wave

Error Correction

• Parity checking
  • Even parity means the bit value needed to make an even number of 1s
  • 00000000 has a even parity of 0
• Checksum
  • Across entire message
• CRC: Cyclic redundancy codes
  • “Magic computation
  • Remainder when message is divided by fixed divisor
  • Can think of it as a series of table-lookups with the original message used as the indexes for the lookups
  • Very, very fast and simple to implement in hardware