On Wed, Feb 5, 2014 at 7:40 PM, Aditya Dhananjay <[email protected]> wrote: > Dear All, > > I suspect there is a bug in cfo_model_impl.h, where calling set_std_dev to > set the std_dev back to 0 causes undesirable effects. > > How to reproduce the bug: > > a) Standard OFDM TX-RX example in GRC. Connect the TX block to the RX block > through this channel model block. > > b) Use a variable slider to control the std_dev of the CFO model block. > > c) Start the flowgraph, with 0 as the initial value of the std_dev. All > should be fine. > > d) Bump up the std_dev and observe high packet errors. > > e) Drop the std_dev back to 0. While we expect the packet error rate to drop > back to 0, but that does not happen. > > Reason: The value of d_cfo might be a high non-zero value. Even though we > drop std_dev back to 0, d_cfo remains high, and continues to create CFO. > > How to fix it: > > In the function set_std_dev, reset the value of d_cfo to 0. > > If someone could verify that this is indeed a bug, that would be very > helpful. Thank you in advance for your help. > > Best regards, > Aditya
Nope, not a bug. You're reducing the standard deviation, but the actual CFO value is not this value but is adjusted based on it. I think more of what you are looking for is a direct way to set the value of the CFO (or something like a reset() function). Tom _______________________________________________ Discuss-gnuradio mailing list [email protected] https://lists.gnu.org/mailman/listinfo/discuss-gnuradio
