Bit Error Rate (BER) estimation

[EngrAdnan]

BER estimation

how is the BER (bit error rate) is calculated during demodulation?
i.e. if a demodulator is demodulating a signal, how can it estimate the running BER?
please ask if anyone has any queries, i will try to explain more my problem.

 

[Gemini1706]

BER estimation

receiver cannot tell BER unless it knows what was transmitted before-hand, maybe a training sequence that is known by both transmitter and receiver.

In general (without training sequence/pre-stored data), only external equipment can do general BER estimation, since the same equipment sends the data and it reads back the received data and makes a comparison.

Is this what you are asking about?

-Gemini

 

[EngrAdnan]

Re: BER estimation

Actually there are some BER estimation methods, i have seen some software demodulators that estimate BER during demodulation of unknown bitstream.
i think they check the points on constellation, that how many points are very near to axises(zero crossings). but i dont know what happens exactly. . . please discuss.
thanks.