Hi Eric,

as a difference I spot that you use two samples per symbol for your 8-
PSK, but only one for your BPSK flow graph. I assume that's
intentional, but could you compare the 2 Sps case, too?

What's the pulse shape your transmitter uses, by the way?

Best regards,
Marcus

On Sat, 2018-10-13 at 15:11 +0800, eric.zeng wrote:
> Hi, My Friends:
> Recently, I follow the application article " Guided Tutorial PSK
> Demodulation", and can make my QPSK/8PSK Tx/Rx demo with AD9361
> successfully.
> Please see blow pic:
> 
> 
> But when I use the same architecture flow chart for BPSK
> demodulation, I found the Costas-loop can't lock correctly.
> Please see below pic:
> It looks like: 
> Maybe the CMA Equalizer do not work correctly under BPSK, so it cause
> the Costas-loop can't lock.
> When I disable the CMA Equalizer and connect the Poly-phase Sync to
> Costas-loop directly, the Costas-loop can lock, I can get good BPSK
> constellation.
> As we know the CMA Equalizer is a right choice for MPSK demod, so is
> there any thing wrong with my BPSK demodulation flow chart?
> Thanks very much!
> 
> 
> 
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