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[Discuss-gnuradio] gr-atsc status

From: Charles Swiger
Subject: [Discuss-gnuradio] gr-atsc status
Date: Thu, 27 Apr 2006 15:59:15 -0400

On Thu, 2006-04-27 at 11:57 -0700, Eric Blossom wrote: 
> Also, can you please post a brief status report about what's the next
> thing to get working?  I'm not sure at this time what's needed to get
> get the next step of the loopback working.

Ok, I've added to gr-atsc cvs these files:

atsc_fs_checker  (field sync checker)

which will compile, load into python and run in a flow graph
but have NOT been tested or debugged. atsc_field_sync_mux
appears to work as far as I can tell by writing to a file
and examining the hexdump (there's a field sync inserted after
every 312 data segments, with valid segment sync, pn511, pn63,
inverted pn63 on FIELD2, another pn63,  vsb mode info, 92 symbols
from pn63 and even the last 12 symbols from the previous segment,
all look ok, except there's junk in the pad space).

It would seem the next test phase would be to loopback
atsc_field_sync_mux to atsc_field_sync_demux BUT mux does not
output a syminfo stream that demux requires so not sure how to
proceed there.  Nothing else seems a logical loopback point as
the only thing left in the transmitter is a symbol mapper then
modulator and filter.

At this point we NEED:

GrFIRfilterFFF            float                        float     band pass root 
raised cosine centered at IF freq (matched filter)
GrAtscFPLL                float                        float     carrier 
tracking freq and phase lock loop with down converting mixer
GrFIRfilterFFF            float                        float     low pass to 
kill unwanted mixer image
GrRemoveDcFFF             float                        float     remove DC 
offset prior to symbol timing module

HAVE but not debugged:
atsc_bit_timing_loop      float                        float,syminfo     track 
symbol & segment timing and do fractional interpolation
atsc_fs_checker           float,syminfo                float,syminfo     look 
for field sync patterns
atsc_equalizer            float,syminfo                float,syminfo     LMS 
atsc_field_sync_demux     float,syminfo                atsc_soft_data_segment   
  remove field syncs and pack into data segments

HAVE WORKING and tested:
atsc_viterbi_decoder      atsc_soft_data_segment       
atsc_mpeg_packet_rs_encoded  Viterbi decoder (12 seg delay)
atsc_deinterleaver        atsc_mpeg_packet_rs_encoded  
atsc_mpeg_packet_rs_encoded  convolutional de-interleaver (52 seg delay)
atsc_rs_decoder           atsc_mpeg_packet_rs_encoded  atsc_mpeg_packet_no_sync 
    Reed-Solomon decoder
atsc_derandomizer         atsc_mpeg_packet_no_sync     atsc_mpeg_packet     
de-whiten with LFSR

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