MT Align To Ideal Symbols (FSK)
- Updated2023-02-17
- 4 minute(s) read
MT Align To Ideal Symbols (FSK)
Locates the first occurrence of the ideal symbol timing instant in the matched filtered input phase waveform, then applies phase-continuous resampling to align the first sample of the input phase waveform to the ideal symbol timing instant for an FSK modulation scheme. The returned waveform is symbol-time aligned such that its first sample corresponds to the optimal (ideal) symbol instant.
Inputs/Outputs

input phase waveform
The continuous-time samples of the modulated complex baseband waveform data. Wire the output complex waveform returned from MT Apply Matched Filter to this parameter.
- The sample rate of the input phase waveform must be an even integer multiple of the expected symbol rate. Use MT Resample (Complex Cluster) to adjust the input phase waveform sampling rate if necessary.
- An appropriate matched filter must be previously applied to the input phase waveform. Use MT Apply Matched Filter to apply the matched filter.

t0
Trigger (start) time of the Y array.
Default value: 0.0

dt
Time interval between data points in the Y array.
Default value: 1.0

Y
The matched-filtered phase of the modulated baseband waveform.

matched filter coefficients
An ordered array containing coefficients for the matched filter that has been applied to the input complex waveform. Wire the matched filter coefficients parameter of MT Generate Filter Coefficients to this parameter. Ensure that the value of the samples per symbol parameter in this node matches the matched samples per symbol value used to generate these filter coefficients.

samples per symbol
Number of samples per information symbol in the input complex waveform.
Default value: 16

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 node continues to align the input complex waveform to ideal symbol timing instants using the previous iteration states.
| TRUE | Resets the node. The node resets on the first call and when reset? is set to TRUE. |
| FALSE | Continues to align the input complex waveform to ideal symbol timing instants using the previous iteration states. |
Default value: TRUE

output phase waveform
The symbol-time-aligned phase of the FSK-modulated baseband waveform. Wire this parameter to MT Decimate Oversampled Waveform followed by MT Map Symbols to Bits to obtain the recovered bits corresponding to the modulated waveform.

t0
Trigger (start) time of the Y array.
Default value: 0

dt
Time interval between data points in the Y array. The reciprocal of this value is equal to the system sample rate.
Default value: 1.0

Y
The symbol-time aligned phase of the modulated waveform.

waveform alignment offset
Location of the ideal symbol timing instant, in samples, relative to the beginning of the input complex waveform. This offset was applied to the output complex waveform. Multiply this value by the dt element of the input complex waveform to calculate the location of the ideal symbol timing instant in seconds.

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