CCSDS Encoder Definition: Difference between revisions

Latest revision as of 15:42, 5 May 2025

CCSDS Encoding class for convolutional encoding with rate 1/2, K=7, and polynomials [109, 79].

Uses Phil Karn's (KA9Q) implementation of the CCSDS encoder for rate 1/2, K=7, and CC polynomial [109, 79]. These are non-adjustable in this encoder. For an adjustable CC encoder where we can set the rate, constraint length, and polynomial, see CC Encoder Definition.

Parameters

(R): Run-time adjustable

Parallelism: It seems that one can create a tensor of one or two dimensions of encoders. More info is needed on this.

Dimension 1: Active when parallelism > 0

Dimension 2: Active when parallelism > 1

Frame bits: When not being used in a tagged stream mode, this encoder will only process frames of the length provided here. If used in a tagged stream block, this setting becomes the maximum allowable frame size that the block may process.

Start state: Initialization state of the shift register.

Streaming behaviour

Specifies how the convolutional encoder will behave and under what conditions.

Streaming: This mode expects an uninterrupted flow of samples into the encoder, and the output stream is continually encoded.
Terminated: Mode designed for packet-based systems. This mode adds rate*(k-1) bits to the output as a way to help flush the decoder.
Tailbiting: Another packet-based method. Instead of adding bits onto the end of the packet, this mode will continue the code between the payloads of packets by pre-initializing the state of the new packet based on the state of the last packet for (k-1) bits.
Truncated: A truncated code always resets the registers to the start state between frames.

Example Flowgraph

This flowgraph can be found at [1]

Source Files

C++ files: ccsds_encoder_impl.cc

Header files: ccsds_encoder_impl.h

Public header files: ccsds_encoder.h

Block definition: variable_ccsds_encoder_def_list.block.yml

@@ Line 1: / Line 1: @@
 [[Category:Block Docs]]
-[[Category:Stub Docs]]
+CCSDS Encoding class for convolutional encoding with rate 1/2, K=7, and polynomials [109, 79].
-This is the template for the [[:Category:Block_Docs|"Page-per-block Docs"]].  This first section should describe what the block does and how to use it, using however many paragraphs necessary.  Note that the title of the wiki page should match the block's name in GRC, i.e. the one defined in the block's .grc file.  Look at the [[FFT]] Block for a good example.
+Uses Phil Karn's (KA9Q) implementation of the CCSDS encoder for rate 1/2, K=7, and CC polynomial [109, 79]. These are non-adjustable in this encoder. For an adjustable CC encoder where we can set the rate, constraint length, and polynomial, see [[CC Encoder Definition]].
-As this is a basic template, it's also in the [[:Category:Stub_Docs|"Stub Docs category"]]. Please improve it.
 == Parameters ==
 (''R''): <span class="plainlinks">[https://wiki.gnuradio.org/index.php/GNURadioCompanion#Variable_Controls ''Run-time adjustable'']</span>
-; Param 1 (''R'')
+; Parallelism
-: Description of parameter, provide any tips or recommended values.  Note that the name of the parameter above should match the param's label that shows up in grc (e.g. Sample Rate).
+: It seems that one can create a tensor of one or two dimensions of encoders. More info is needed on this.
+; Dimension 1
+: Active when parallelism > 0
+; Dimension 2
+: Active when parallelism > 1
+; Frame bits
+: When not being used in a tagged stream mode, this encoder will only process frames of the length provided here. If used in a tagged stream block, this setting becomes the maximum allowable frame size that the block may process.
-; Param 2
+; Start state
-: blah blah blah
+: Initialization state of the shift register.
+; Streaming behaviour
+: Specifies how the convolutional encoder will behave and under what conditions.
+:; Streaming: This mode expects an uninterrupted flow of samples into the encoder, and the output stream is continually encoded.
+:; Terminated: Mode designed for packet-based systems. This mode adds rate*(k-1) bits to the output as a way to help flush the decoder.
+:; Tailbiting: Another packet-based method. Instead of adding bits onto the end of the packet, this mode will continue the code between the payloads of packets by pre-initializing the state of the new packet based on the state of the last packet for (k-1) bits.
+:; Truncated: A truncated code always resets the registers to the start state between frames.
 == Example Flowgraph ==
+This flowgraph can be found at [https://github.com/gnuradio/gnuradio/blob/master/gr-fec/examples/fecapi_async_decoders.grc]
-Insert description of flowgraph here, then show a screenshot of the flowgraph and the output if there is an interesting GUI.  Currently we have no standard method of uploading the actual flowgraph to the wiki or git repo, unfortunately.  The plan is to have an example flowgraph showing how the block might be used, for every block, and the flowgraphs will live in the git repo.
+[[File:Fecapi_async_decoders_fg.png|800px]]
 == Source Files ==
 ; C++ files
-: [https://github.com/gnuradio/gnuradio TODO]
+: [https://github.com/gnuradio/gnuradio/blob/master/gr-fec/lib/ccsds_encoder_impl.cc ccsds_encoder_impl.cc]
 ; Header files
-: [https://github.com/gnuradio/gnuradio TODO]
+: [https://github.com/gnuradio/gnuradio/blob/master/gr-fec/lib/ccsds_encoder_impl.h ccsds_encoder_impl.h]
 ; Public header files
-: [https://github.com/gnuradio/gnuradio TODO]
+: [https://github.com/gnuradio/gnuradio/blob/master/gr-fec/include/gnuradio/fec/ccsds_encoder.h ccsds_encoder.h]
 ; Block definition
-: [https://github.com/gnuradio/gnuradio TODO]
+: [https://github.com/gnuradio/gnuradio/blob/master/gr-fec/grc/variable_ccsds_encoder_def_list.block.yml variable_ccsds_encoder_def_list.block.yml]

CCSDS Encoder Definition: Difference between revisions

Latest revision as of 15:42, 5 May 2025

Parameters

Example Flowgraph

Source Files

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