MT Convolutional Encoder (Rate)
- Updated2023-02-17
- 4 minute(s) read
MT Convolutional Encoder (Rate)
Generates an encoded bit stream based on a code rate that you select. The code rate is equal to the ratio of the data word length to the code word length. This node allows you to choose a code rate of 1/2, 1/3, 1/4, 2/3, or 3/4, using the rate parameter. Use MT Convolutional Encoder (Generator Matrix) to set a custom value as the code rate.
Inputs/Outputs
input bit stream
Bit sequence representing the data bits to encode. Use the bits generated by MT Generate Bits to produce this bit stream or wire a custom data bit stream to this parameter.
rate
The convolutional code rate, which is a ratio of k/n, where k is the input data word length and n is the output code word length.
| 1/2 |
Supports constraint lengths of 3,4,5,6,7,8,9,10,11,12,13,14,15,16,17 |
| 1/3 |
Supports constraint lengths of 3,4,5,6,7,8,9,10,11,12,13,14 |
| 1/4 |
Supports constraint lengths of 3,4,5,6,7,8,9,10,11,12,13,14 |
| 2/3 |
Supports constraint lengths of 2,3,4,5,6 |
| 3/4 |
Supports constraint lengths of 2,3,4 |
Default value: 1/2
constraint length
The maximum number of encoded bits that can be affected by a single input bit. This value represents (1 + maximal memory order), where maximal memory order refers to the length of the longest shift register chain in the convolutional encoder.
Default value: 3
initial state
The encoder initialization state for the k(K-1) shift registers, where k is the input data word length and K specifies the constraint length. On the first call to this node, and thereafter when you configure reset? to TRUE, the encoder state is reset to this value on each call to this node. When you configure reset? to FALSE, the final state from the previous iteration is used in subsequent calls to this node and LabVIEW ignores the initial state parameter.
Default value: 0
error in
Error conditions that occur before this node runs.
The node responds to this input according to standard error behavior.
Default value: No error
reset?
A Boolean that determines whether the internal state of the encoder is cleared.
| TRUE | Clears any buffered bits from previous iterations. Also initializes the encoder to start from the initial state parameter that you specify. |
| FALSE | Continues encoding from the previous iteration. Any buffered bits from the previous iteration are added to the beginning of the input bit stream prior to encoding. |
Default value: TRUE
output bit stream
Convolutional-encoded code word returned by this node. Wire this parameter to MT Convolutional Decode to recover the input data stream.
final state
The value for the k(K-1) shift registers as the right-aligned (least significant) k(K-1) bits when this node completes execution, where K is the constraint length and k is the data word length in bits.
error out
Error information.
The node produces this output according to standard error behavior.