1. Given that set_damping_factor() requires the value to be in [0.0, 1.0], 2 * d_nfilters looks quite wrong. I wonder if it was supposed to be 2.0 / d_nfilters. This is probably overridden by a call to set_damping_factor() in a typical flowgraph.
I'm not familiar enough with the block to comment on 2 and 3 without some study. Please submit an issue at https://github.com/gnuradio/gnuradio/issues so we don't lose this info. On Sat, Apr 29, 2023 at 3:56 AM Saurav Roy <saurav...@iisc.ac.in> wrote: > Dear all, > I have a few questions about the Polyphase Clock Sync Block in reference > to > https://github.com/gnuradio/gnuradio/blob/master/gr-digital/lib/pfb_clock_sync_ccf_impl.cc > > > 1. line no 67: d_damping = 2 * d_nfilters; --> d_nfilters=32, should > this not be around 0.707 > > 2. line no 366: based on the 'time_est' tag, determine the filter > index, d_k. But, this completely bypasses the TED and the control loop as > in line no 374 d_filtnum = (int)floor(d_k); > then why do we need this Polyphase Clock Sync Block at all? > > > > 1. How does the main loop take care of which input samples are > selected for the determination of d_error and d_k such that all the input > samples come from the same input symbol? > > With thanks and regards > Saurav > >
