MT Convolutional DeInterleaver (Generic)

MT Convolutional DeInterleaver (Generic)

Performs the deinterleaving process with delays that you specify for each branch.

A convolutional deinterleaver is the inverse of a convolutional interleaver. In convolutional deinterleaving, data elements pass cyclically through a set of branches. That is, in an N branch convolutional deinterleaver, the element 0 goes through branch 0, element 1 goes through branch 1, element N-1 goes through branch N-1, element N goes through branch 0, and so on. Each branch has different delays associated with it. Hence the data sent to each deinterleaver branch is delayed by a specific amount (the amount of delay in that particular branch) before the deinterleaver returns the data. In a convolutional interleaver, if the delay in branch number n is d_n, maximum delay is max_delay and the minimum delay is min_delay, then for the corresponding convolutional deinterleaver, the delay in branch number n is: D_n = (max_delay+min_delay)-d_n.

Inputs/Outputs

data in

The input data to the deinterleaver.

interleaver delays

The number of delays individually for each branch of the corresponding interleaver. The number of elements in this array determines the number of branches, and the value of each element denotes the delay for that branch. For example, if interleaver delays is [3,6,9,2], it implies that there are four branches; branch 0 has 3 delays, branch 1 has 6 delays, and so on.

Note You must specify a value for this parameter.

initial state

The shift register values when the convolutional deinterleaver begins operation.

error in

Error conditions that occur before this node runs.

The node responds to this input according to standard error behavior.

Standard Error Behavior

Default value: No error

reset?

A Boolean that determines whether to check the current input parameters. The current input parameters are always checked on the first run of this node.

TRUE	Checks input parameters.
FALSE	Does not check input parameters.

Default value: TRUE

data out

The output of the convolutional deinterleaver.

error out

Error information.

The node produces this output according to standard error behavior.

Standard Error Behavior

Examples of Convolutional Interleaving and Deinterleaving

The following example demonstrates convolutional interleaving and deinterleaving. Let the data in be: x0, x1, x2, x3, x4, x5, x6, x7, x8, x9, x10, x11, x12, x13, …

Interleaver Input Interleaver Output

D = unit delay in the path.

Assume for this example that the unit delay = 1, and the initial state shift registers are initialized with values of 0 for both the interleaver and the deinterleaver.

Interleaved Data: x0, 0, 0, 0, x4, x1, 0, 0, x8, x5, x2, 0, x12, x9, …

Deinterleaver Input Deinterleaver Output

Deinterleaved Data: 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, x0, x1, x2, x3, x4, x5, x6, x7, x8, x9, …