MT MLSE Demapper (MSK)

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Maps an MSK-modulated complex baseband waveform to an output bit stream using maximum likelihood sequence estimation (MLSE). The node expects the input complex waveform to be synchronized, in every aspect, to the receiver.

Note

This node assumes that the sample rate of the input complex waveform is exactly samples per symbol × the symbol rate. If this relationship does not apply to your application, use MT Resample (Complex Cluster) to resample the waveform to the desired sample rate.

Inputs/Outputs
Compatibility

input complex waveform

The modulated complex baseband waveform data.

t0

Trigger (start) time of the Y array.

Default: 0.0

dt

Time interval between data points in the Y array.

Default: 1.0

Y

The complex-valued signal-only baseband modulated waveform. The real and imaginary parts of this complex data array correspond to the in-phase (I) and quadrature-phase (Q) data, respectively.

MSK system parameters

Parameter values defining the MSK system. Wire the MSK system parameters cluster of MT Generate MSK System Parameters to this cluster. Do not alter the values.

differential encoding enable

Status of the differential encoding.

disable	Disables differential encoding for input symbols.
enable	Enables differential encoding for input symbols.

Default: enable

samples per symbol

An even, positive number of samples dedicated to each symbol. Multiply this value by the symbol rate to determine the sample rate.

Default: 16

pulse shaping filter coefficients

An ordered array containing the coefficients of the pulse-shaping filter used during the modulation of the received waveform.

MSK MLSE settings

MSK MLSE settings.

traceback depth

Number of trellis stages to trace back during the Viterbi decoding process. The output bit sequence is delayed, in time, by this amount with respect to the incoming waveform.

Default: 15

block size

Length, in symbols, of a block of the received waveform, used during block-wise processing. At the beginning of each block, the node resets the Viterbi decoding process. Each block overlaps with the previous block for a number of symbols equal to traceback depth. To enable block-wise processing, set this value to a positive integer greater than the traceback depth.

Default: -1

error in

Error conditions that occur before this node runs. The node responds to this input according to standard error behavior.

Default: no error

reset?

A Boolean that determines whether the node continues demodulating using the previous iteration states.

TRUE	Restarts the demodulator. The node resets on the first call and when reset? is set to TRUE.
FALSE	Continues demodulating using the previous iteration states.

Default: TRUE

output bit stream

The demapped information bit stream.

error out

Error information. The node produces this output according to standard error behavior.