Re: Measure bit error rate.

[Ed Criscuolo]

On 3/6/20 6:00 AM, Md. Atiqur Rahman wrote:
> Hello Everyone,
> Again I have a question for another issue. In my project work, the
> baseband complex signal generation and later on convert it to RF signal
> is the main idea. These task is completed and I can successfully
> demodulate the RF signal from the spectrum analyzer.
> However, the signal generation was from a 'random signal' source and I
> need to measure the BER. How can I do it? I read some documents and it
> is mostly saying need a file sink, but what would be the file formate of
> the sink?
> I hope I will get some response.
> Thank you in advance.

The typical way to measure BER is to use a repeating pseudo-random data
sequence of some known fixed length for the transmitted data.

The receiver needs to try and do a correlation between this repeatable
sequence and the received bits, sliding the comparison offset one bit at 
a time until the maximum correlation is found.  Then, you can count
the number of wrong bits vs the total bits in the sequence to get a BER 
figure.

Note; when using phase modulation, you may need to use two (BPSK) or
four (QPSK) possible symbol-to-bit decodings for each comparison in
order to find the right rotation of the phase constellation.

As a side note, this is essentially the same algorithm that is used
to acquire a spread-spectrum signal.

@(^.^)@  Ed