RPC-UHF RADIOMETRIX [Radiometrix Ltd], RPC-UHF Datasheet - Page 19

• Manufacturer Part Number: RPC-UHF
• Description: Radio Packet Controller
• Manufacturer: RADIOMETRIX [Radiometrix Ltd]

Each byte in the RPC's buffer is expanded into a 12 bit symbol prior to sending. The symbol coding has
the following properties :-
• Perfect 50:50 balance, i.e.. always 6 one's & 6 zero's
• There are never more than 4 consecutive one's or zero's. This minimises the low frequency
• Minimum Hamming distance = 2, i.e.. each code is different from any other code by a minimum of 2
• In general only 256 of 4096 (6.25%) possible codes are valid, i.e.. a 93.75 % probability of trapping a
• Preamble and the Frame sync codes are not part of the symbol alphabet, a 'clash' signal will cause
Check Sum
Since the receiver checks each symbol for integrity, a simple 8 bit check sum is used to test for overall
packet integrity. This is also coded into a 12 bit symbol prior to transmission.
Radiometrix Ltd, RPC
components in the code and allows fast settling times to be used for the receivers' data slicer.
bits, thus all odd number of bit errors will always be detected.
byte error.
immediate termination of the current decode followed by an attempt to lock to the new signal.
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