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CC2543 preamble-sync at 2 Mbit

Bjorn Nilsson
Prodigy 10 points

Can't find in the spec. for 2 Mbit mode:

What preamble length and sync length to chose? What speed is preamble and sync sent in, 2Mbit in 2 Mbit mode?

  • 0
    TI__Guru 56590 points

    Hello Bjørn,

    The minimum without AGC enabled is 1 byte of preamble, the minimum with AGC enabled is 4 bytes of preamble. The AGC needs a minimum of 10.7 us with energy in front of the mandatory single preamble byte (i.e. 4 bytes of preamble gives 3 extra preamble bytes) . We do recommend to enable the AGC for 2 Mbps. Everything is transmitted over the air at 2 Mbps.

    A correct packet with the AGC enabled must consist of:

    • Between 11 and 85 us with preamble or tone, followed by
    • 1 preamble-byte (10101010 eller 01010101) - 4 us, followed by
    • sync word (16-32 bytes), followed by
    • Header, payload and CRC

    The longer the sync word the more robust the performance will be. The recommended 32 bit gives better performance than 16. If you choose 16 bit it is very important to choose sync words with good correlation properties. If you really need less than 32 bit i would recommend 24 bit over 16. If you use 32 bit you will have a more robust sync word detection and this gives you the option to use all the 256 different values for an additional optional address byte without having to take into considerations how it will impact the sync word detection as this will be minimal.