[Discuss-gnuradio] Costas loop and M&M algorithm on FPGA

[Phone Naing MYINT]

Hi,

 

Anyone here implemented freq/phase correction and symbol timing correction in USRP’s FPGA?

 

Recently I implemented Costas loop and Muller & Mueller algorithm in RTL by referring the gnuradio code. Now I’m testing it on FPGA. I can get correct demodulated data(DQPSK) at initial few thousand symbols. After that I’m getting all rubbish data.

 

I think the problem with my RTL implementation is not good enough bit-resolution (unlike implementation on PC). Currently I’m using 15-bits resolution for decimal part. Anyone has any suggestion ?

 

PN