[Tinyos-help] Bit Error Rate for CC2420

[Rafael Marin Perez]

Hi all,

I have saw a method for calculating bit error rates (BER) from packet error 
rates (PER) for the CC1000 radio  in Mica RFM with SecDed encoding. 

/* The loss table comes from this analysis: The probability of a packet
* failing can be decomposed into the probability the start symbol will not be
* detected and the probability there will be a double bit error in a data byte
* (such that SecDed can't recover and there will be a CRC error).
* This can be alternatively thought of as the probability of a packet
* succeeding (Pr) is the product of the probability the start symbol is
* detected correctly (Ps) and the probability there is not an unrecoverable
* bit error (Pe). So,
*       				Pr = Ps * Pe
* Let Pb be the bit error rate.
*
* Ps is simply the probability that there will not be a single bit error in
* the start symbol. The start symbol is nine bits long; the probability that
* it will be received correctly is equal to:
*      (1 - Pb)^9.
*
* Pe is the probability that every data byte is received correctly. There are
* 36 data bytes, which are in a 3:1 encoding of which one bit in each byte is
* not examined (a 21:8 encoding, efffectively). This encoding is composed of 8
* data bits and 13 parity bits. It succeeds if:
    * 1) there are no data bit errors, or
    * 2) there is one data bit error and there are no errors in 5 specific
    * parity bits
*
* Pe is equal to the probability of zero or one bit errors, or:
*      (1 - Pb)^8   +   8 * (Pb * (1 - Pb)^7 * (1 - Pb)^5)
*      (1 - Pb)^8   +  8 * Pb * (1 - Pb)^12
*     (zero errors)          (one error)
*     (((1 - Pb)^8   +  (8 * (1 - Pb)^12)^36
*
* The final equation is therefore
*     ((1 - Pb)^8   +  ((8 * Pb * (1 - Pb)^12)^36 * (1 - Pb)^9)
*
* The table was generated by iterating through bit error rates at a
* granularity of .0001% and finding the bit error rate that best fits a packet
* error rate. */

But I need a method for calculating bit error rates(BER) from packet error 
rates (PER) for the CC2420 radio in MicaZ or Telos with O-QPSK encoding. 
Or Forward Error Correction (FEC).

Thanks, very much.

Rafa.