diff options
Diffstat (limited to 'tests/correlator/epy_block_0.py')
| -rw-r--r-- | tests/correlator/epy_block_0.py | 32 |
1 files changed, 26 insertions, 6 deletions
diff --git a/tests/correlator/epy_block_0.py b/tests/correlator/epy_block_0.py index ddae02a..dbdadd1 100644 --- a/tests/correlator/epy_block_0.py +++ b/tests/correlator/epy_block_0.py @@ -5,6 +5,12 @@ from gnuradio import gr class blk(gr.sync_block): + """ + Apply phase and frequency correction where there is a correlation peak tag. + + The correlation peak tags are NOT propagated, and instead replaced with a + frame_start tag. + """ def __init__(self): gr.sync_block.__init__( self, @@ -22,7 +28,17 @@ class blk(gr.sync_block): self.lastfreq = 0 def block_phase(self, start, end): - # compute number of samples in block + """ + Compute a vector for the phase and frequency correction for the samples + between two tags (start and end). + + @param start Tag where the samples should start to be corrected + @param end Tag where to stop correcting + + @return A vector of phase values for each sample. To correct the samples + the data should be multiplied with np.exp(-1j * phase) + """ + # compute number of samples between tags nsamples = end.offset - start.offset # unpack pmt values into start and end phase @@ -44,10 +60,10 @@ class blk(gr.sync_block): self.lastfreq = freq # debugging - print(f"Correction for block of {nsamples:2d} samples is " \ + print(f"Correction for chunk of {nsamples:2d} samples is " \ f"sphase={sphase: .4f} rad and freq={freq*1e3: .4f} milli rad / sample") - # compute block values + # compute chunk values return sphase * np.ones(nsamples) + freq * np.arange(0, nsamples) def work(self, input_items, output_items): @@ -73,11 +89,11 @@ class blk(gr.sync_block): # compute "the middle" enough_samples = lambda pair: ((pair[1].offset - pair[0].offset) > 0) pairs = list(filter(enough_samples, zip(tags, tags[1:]))) - blocks = [ self.block_phase(start, end) for (start, end) in pairs ] - middle = np.concatenate(blocks) if blocks else [] + chunks = [ self.block_phase(start, end) for (start, end) in pairs ] + middle = np.concatenate(chunks) if chunks else [] # compute values at the end, we do not have informations about the future - # but we can use the frequency of the last block to approximate + # but we can use the frequency of the last tag to approximate nback = len(inp) - (tags[-1].offset - counter) print(f"Processing {nback} samples at the back of the buffer") end = np.ones(nback) * pmt.to_python(tags[-1].value) \ @@ -99,6 +115,10 @@ class blk(gr.sync_block): # save last tag for next call self.last = tags[-1] + # add tags + for tag in tags: + self.add_item_tag(0, tag.offset, pmt.intern("frame_start"), pmt.PMT_T) + # FIXME: should return `length' but then the last sample is not # included and self.last does something weird return len(out) |