Hello,
We are working on noise estimation for the uplink lte scenario. The designed algorithm for CFO estimation is working for high SNR values. But for low SNR values we are unable to extract the signal. So if anyone have any suggestions please help in this regard.
Thanking you in advance
The DMRS based algorithm is used which will calculate the offset by conjugate multiply followed by angle and frequency offset calculation.
have you tried CP-based? I tried before and it seems that for a large number of averages you can get good performance for low SNR.
The CP based method i tried with comparing the 18 samples with the last 18 of previous symbols. But in this method also the approximation is not achieving. The CP based method working when we know the txWaveform correctly and conjugate multiply with the grid followed by angle calculation and frequency offset calculation (Which is not possible in actual scenario, as we dont have the real samples without impairments).
Thank you for your response.
I'm not following you, but in the CP-based CFO estimation method you correlate the CP with the last part of the current OFDM symbol, which happens to be equal to the CP section, however, you do an average over several symbols, so that your estimation accuracy is better. The accuracy will be very small if you use just one OFDM symbol. have a look at this paper: Article An efficient CFO estimation algorithm for the downlink of 3GPP-LTE