This describes the signal flow through the gnuradio-0.9 ATSC Transmitter

and Receiver programs.

ATSC Transmitter

================

module                  input                         output                       notes

--------------------    ----------------              -------------------          --------

VrFileSource            "MPEG transport stream"       atsc_mpeg_packet

GrAtscRandomizer        atsc_mpeg_packet              atsc_mpeg_packet_no_sync     whiten data with LFSR

GrAtscRSEncoder         atsc_mpeg_packet_no_sync      atsc_mpeg_packet_rs_encoded  Reed-Soloman encoder

GrAtscInterleaver       atsc_mpeg_packet_rs_encoded   atsc_mpeg_packet_rs_encoded  convolutional interleaver

GrAtscTrellisEncoder    atsc_mpeg_packet_rs_encoded   atsc_data_segment            trellis encoder

GrAtscFieldSyncMux      atsc_data_segment             atsc_data_segment            add in field syncs

GrAtscSymbolMapper      atsc_data_segment             float                        map [0,7] to +/- {1,3,5,7} and add pilot    

GrWeaverModHead         float                         float,float                  front half of Weaver VSB modulator

GrFIRfilterFFF (2x)     float                         float                        low pass root raised cosine (matched filter)

GrWeaverModTail         float,float                   short                        back half of Weaver VSB modulator

VrFileSink              short                         "16-bit passband data"

ATSC Receiver

=============

module                    input                        output                       notes         

--------------------      ----------------             -------------------          -------

VrFileSource              "16-bit passband data"       short

GrConvertSF               short                        float                        convert short to float

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

GrAtscBitTimingLoop3      float                        float,syminfo                track symbol & segment timing and do fractional interpolation

GrAtscFieldSyncChecker    float,syminfo                float,syminfo                look for field sync patterns

GrAtscEqualizer           float,syminfo                float,syminfo                LMS equalizer

GrAtscFieldSyncDemux      float,syminfo                atsc_soft_data_segment       remove field syncs and pack into data segments

GrAtscViterbiDecoder      atsc_soft_data_segment       atsc_mpeg_packet_rs_encoded  Viterbi decoder (12 seg delay)

GrAtscDeinterleaver       atsc_mpeg_packet_rs_encoded  atsc_mpeg_packet_rs_encoded  convolutional de-interleaver (52 seg delay)

GrAtscRSDecoder           atsc_mpeg_packet_rs_encoded  atsc_mpeg_packet_no_sync     Reed-Solomon decoder

GrAtscDerandomizer        atsc_mpeg_packet_no_sync     atsc_mpeg_packet             de-whiten with LFSR

VrFileSink                atsc_mpeg_packet             "MPEG transport stream"