CCSDS Encoder Definition

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

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.

Source Files

C++ files

Here

Header files

Here

Public header files

Here

Block definition

Yaml