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.