[Discuss-gnuradio] BPSK problem: intermittent inter-symbol interference and phase change

Hi,

I implemented a simple BPSK system. I ran simulation in GNURadio with no channel effect added. Some of the received packets look weird. The first attachment shows three received packet. They are supposed to be identical. However, the second one suffers from ISI and a phase change.

I also attached my grc files. Could someone take a look at it and help me figure out the cause please? Thank you very much!

Regards,

Edwin