diff options
Diffstat (limited to 'tests/correlator/epy_block_0.py')
| -rw-r--r-- | tests/correlator/epy_block_0.py | 36 |
1 files changed, 23 insertions, 13 deletions
diff --git a/tests/correlator/epy_block_0.py b/tests/correlator/epy_block_0.py index 6b47e80..e7599c9 100644 --- a/tests/correlator/epy_block_0.py +++ b/tests/correlator/epy_block_0.py @@ -21,9 +21,20 @@ class blk(gr.sync_block): # of the previous block to correct the first values of the next block self.last = None - # to compute the values that are at the end we need to know the frequency - # of the last block - self.freq = 1 + # both the phase and frequency corrections should go through a low pass + # filter to avoid werid jumps in the correction. to do that, there are + # two buffers with an index + self.index = 0 + self.length = 7 + self.freq = np.zeros(self.length) + + def lpf_freq(self, new_sample): + # save new sample + self.freq[self.index] = new_sample + # increment index + self.index = (self.index + 1) % self.length + + return np.sum(self.freq) / self.length def block_phase(self, start, end): # compute number of samples in block @@ -34,16 +45,9 @@ class blk(gr.sync_block): ephase = pmt.to_python(end.value) # compute frequency offset between start and end + # and run it through a low pass filter (mean) freq = (sphase - ephase) / nsamples - - # save this frequency values to compute the end block, unless frequency - # has changed too fast, in that case replace the current values with - # the previous one . This is effectively like a low pass filter. - if abs(freq / self.freq) > 4: - freq = self.freq - else: - self.freq = freq - + freq = self.lpf_freq(freq) # debugging print(f"Correction for block of {nsamples:2d} samples is " \ @@ -64,6 +68,11 @@ class blk(gr.sync_block): is_phase = lambda tag: pmt.to_python(tag.key) == "phase_est" tags = list(filter(is_phase, self.get_tags_in_window(0, 0, len(inp)))) + if not tags: + print(f"There were no tags in {len(inp)} samples!") + out[:] = inp + return len(out) + # debugging print(f"Processing {len(tags)} tags = {tags[-1].offset - tags[0].offset} " \ f"samples out of {len(inp)} input samples") @@ -78,7 +87,8 @@ class blk(gr.sync_block): # but we can use the frequency of the last block to approximate nback = len(inp) - (tags[-1].offset - self.counter) print(f"Processing {nback} samples at the back of the buffer") - end = np.ones(nback) * pmt.to_python(tags[-1].value) + self.freq * np.arange(0, nback) + endfreq = self.lpf_freq(self.freq[-1]) + end = np.ones(nback) * pmt.to_python(tags[-1].value) + endfreq * np.arange(0, nback) # compute the "start", using the last tag from the previous call nfront = tags[0].offset - self.counter |