GNU Radio ATSC_8VSB Transmitter Simulation

Figure 1 CBLFT UHF CH25

In the previous post, I discussed using Splat! to predict the receive level of an RF signal. In particular I considered CBLFT UHF CH25 as received from the CN Tower as shown above in Figure 1. In order to study ATSC_8VSB which is the DTV standard used in North America, GNU Radio can be used to actually simulate a transmitter and receiver.

Figure 2 ATSC DTV Standard Signal Flow

Figure 2 shows the block diagram of ATSC_8VSB from Ref.1. Video information is compressed by an MPEG-2 video coder and audio is compressed by a Dolby AC-3 coder. These two streams are mixed with Auxiliary & Control data to form a MPEG-2 transport stream of packets. These packets undergo Channel Coding and 8VSB Modulation with modules as shown in Figure 3.

Figure 3 ATSC Channel Coding & Modulation Modules

Figure 4 shows a GNU Radio simulation of ATSC_8VSB transmission. An MPEG-2 video file is read into the simulation and processed by the channel coding blocks. The signal is then 8VSB modulated to UHF CH25 and the spectrum displayed.

Figure 4 UHF CH25 ATSC_8VSB Simulation with Video & Spectrum

References:

#1 – “A/53 ATSC Digital Television Standard Parts 1 – 6, 2007
https://www.atsc.org/standard/a53-atsc-digital-television-standard

#2 – “GNU Radio 3.7.0 Documentation – gnuradio.atsc Signal Blocks”
https://www.gnuradio.org/doc/sphinx-3.7.0/atsc/index.html

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