Hi everyone,

I have a question about benchmark decoding. I'm using bpsk mod and demod.

In order to understand what's happening in the demodulation process, I added a 
file sink after time_recov block and after unpack block respectively. According 
to my understanding, the receiver block does the mapping and decision making 
process. It maps the complex number in rx_time_recov.32fc to 1 if the complex 
number is bigger than zero. It will map the complex number in 
rx_time_recov.32fc to 0 if the complex number is smaller than zero. And this 
mapping result, 1 or 0, is written into rx_unpack.8b.

However, in real experiment, I found wired result. Sometimes the mapping is 
using the algorithm as above, sometimes it is totally the opposite way. 
(complex number in rx_time_recov.32fc smaller than zero will be mapped as 1). 
Even this algorithm is not the same within one packet. For instance, the access 
code is mapped using one algorithm, and the payload is mapped the other way. 

I don't understand why this is happening. Is there anything to do with the 
phase error or anything? Can anyone give me some suggestions on how it works?

Thanks!
Ada
                                          
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