[Discuss-gnuradio] Did anyone know the ofdm PN correlation process? Why the output value of PN-Peak is very small?

[Yingjie Chen]

Hi guys,

Thanks in advance .

I am doing the ofdm preamble sync test, using the pn-peak PN Correlation method.
Please refer to ofdm_sync_pn.py file.

 Before the normalization process, I open the gr__peak_detector_fb.cc file, and try the print out the peak_val, to see if the peak_value is very large. According the PN correlation process, I believe the peak value is subjected to ifft_length, at least 64 or more. But the actual output value is very small, nearly 2 or 3. I am so confused.

The PN correlation method can be referred to T. M. Schmidl and D. C. Cox, "Robust Frequency and Timing Synchonization for OFDM," IEEE Trans. Communications, vol. 45,no. 12, 1997.