MT Pulse Shaping Filter VI

LabView Digital Modulation

MT Pulse Shaping Filter VI

Generates a sampled continuous-time I/Q baseband waveform from the discrete-valued input symbols by applying a pulse-shaping filter.

Use the pull-down menu to select an instance of this VI.

Details

MT Apply Pulse Shaping Filter (Generic)

This polymorphic instance applies a pulse-shaping filter to an input stream comprised of PAM, ASK, QAM, and nonoffset PSK-modulated symbols. Separate polymorphic instances are available for offset PSK, FSK, and MSK.

MT Apply Pulse Shaping Filter (Generic)

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symbols specifies an array of symbols (comprised of frequency deviations) corresponding to information bits. Wire the symbols parameter of the MT Map Bits to Symbols VI to this parameter.

c1ddbl.gif

pulse shaping filter coefficients specifies an ordered array containing sample-spaced coefficients for the desired pulse-shaping filter. Wire the pulse shaping filter coefficients parameter of the MT Generate Filter Coefficients VI to this parameter. Ensure that the value of the samples per symbol passed to this VI matches the pulse shaping samples per symbol value used to generate the filter coefficients.

Note   When reset? is set to TRUE, there is a transient response of ½ the filter length at the start of the modulated signal, and the returned data is shortened by approximately ½ the filter length. When reset? is set to FALSE, the VI uses data from the previous iteration to eliminate the transient.
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samples per symbol specifies the number of samples per information symbol in the output complex waveform. Multiply this value by the symbol rate to determine the system sampling rate. The default is 16.

cdbl.gif

symbol rate specifies the symbol rate in symbols per second. The default is 1.0.

cbool.gif

reset? specifies whether the VI continues pulse-shape filtering using the previous iteration states. The pulse-shaping process is reset on the first call and when reset? is set to TRUE. Set reset? to FALSE to begin pulse shaping at the previous iteration state on subsequent calls. The default is TRUE.

ccclst.gif

error in (no error) can accept error information wired from previously called VIs. Use this information to decide if any functionality should be bypassed in the event of errors from other VIs. Right-click the front panel error in control and select Explain Error or Explain Warning from the shortcut menu for more information about the error.

cbool.gif

status is TRUE (X) if an error occurred or FALSE (checkmark) to indicate a warning or that no error occurred. Right-click the front panel error in control and select Explain Error or Explain Warning from the shortcut menu for more information about the error.

ci32.gif

code identifies the error or warning code. Right-click the front panel error in control and select Explain Error or Explain Warning from the shortcut menu for more information about the error.

cstr.gif

source describes the origin of the error or warning. Right-click the front panel error in control and select Explain Error or Explain Warning from the shortcut menu for more information about the error.

icclst.gif

output complex waveform returns the output pulse-shaped continuous-time I/Q baseband waveform.

idbl.gif

t0 returns the trigger (start) time of the Y array.

idbl.gif

dt returns time interval between data points in the Y array. The reciprocal of this value is equal to the system sampling rate.

i1dcdb.gif

Y returns 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.

icclst.gif

error out passes error or warning information out of a VI to be used by other VIs. Right-click the front panel error out indicator and select Explain Error or Explain Warning from the shortcut menu for more information about the error.

ibool.gif

status is TRUE (X) if an error occurred or FALSE (checkmark) to indicate a warning or that no error occurred. Right-click the front panel error out indicator and select Explain Error or Explain Warning from the shortcut menu for more information about the error.

ii32.gif

code is the error or warning code. Right-click the front panel error out indicator and select Explain Error or Explain Warning from the shortcut menu for more information about the error.

istr.gif

source describes the origin of the error or warning. Right-click the front panel error out indicator and select Explain Error or Explain Warning from the shortcut menu for more information about the error.

MT Apply Pulse Shaping Filter (Offset PSK)

This polymorphic instance applies a pulse-shaping filter to an input stream comprised of offset PSK-modulated symbols. The VI shifts the Q-phase baseband data by ½ symbol relative to the I-phase baseband data, so the first Q-symbol lasts for the duration of 1.5 symbol periods.

Note  Use the generic instance of this VI for nonoffset PSK-modulated signals.

MT Apply Pulse Shaping Filter (Offset PSK)

c1dcdb.gif

symbols specifies an array of symbols (comprised of frequency deviations) corresponding to information bits. Wire the symbols parameter of the MT Map Bits to Symbols VI to this parameter.

c1ddbl.gif

pulse shaping filter coefficients specifies an ordered array containing sample-spaced coefficients for the desired pulse-shaping filter. Wire the pulse shaping filter coefficients parameter of the MT Generate Filter Coefficients VI to this parameter. Ensure that the value of the samples per symbol passed to this VI matches the pulse shaping samples per symbol value used to generate the filter coefficients.

Note   When reset? is set to TRUE, there is a transient response of ½ the filter length at the start of the modulated signal, and the returned data is shortened by approximately ½ the filter length. When reset? is set to FALSE, the VI uses data from the previous iteration to eliminate the transient.
ci32.gif

samples per symbol specifies the number of samples per information symbol in the output complex waveform. Multiply this value by the symbol rate to determine the system sampling rate. The default is 16.

cdbl.gif

symbol rate specifies the symbol rate in symbols per second. The default is 1.0.

cbool.gif

reset? specifies whether the VI continues pulse-shape filtering using the previous iteration states. The pulse-shaping process is reset on the first call and when reset? is set to TRUE. Set reset? to FALSE to begin pulse shaping at the previous iteration state on subsequent calls. The default is TRUE.

ccclst.gif

error in (no error) can accept error information wired from previously called VIs. Use this information to decide if any functionality should be bypassed in the event of errors from other VIs. Right-click the front panel error in control and select Explain Error or Explain Warning from the shortcut menu for more information about the error.

cbool.gif

status is TRUE (X) if an error occurred or FALSE (checkmark) to indicate a warning or that no error occurred. Right-click the front panel error in control and select Explain Error or Explain Warning from the shortcut menu for more information about the error.

ci32.gif

code identifies the error or warning code. Right-click the front panel error in control and select Explain Error or Explain Warning from the shortcut menu for more information about the error.

cstr.gif

source describes the origin of the error or warning. Right-click the front panel error in control and select Explain Error or Explain Warning from the shortcut menu for more information about the error.

icclst.gif

output complex waveform returns the output pulse-shaped continuous-time I/Q baseband waveform.

idbl.gif

t0 returns the trigger (start) time of the Y array.

idbl.gif

dt returns time interval between data points in the Y array. The reciprocal of this value is equal to the system sampling rate.

i1dcdb.gif

Y returns 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.

icclst.gif

error out passes error or warning information out of a VI to be used by other VIs. Right-click the front panel error out indicator and select Explain Error or Explain Warning from the shortcut menu for more information about the error.

ibool.gif

status is TRUE (X) if an error occurred or FALSE (checkmark) to indicate a warning or that no error occurred. Right-click the front panel error out indicator and select Explain Error or Explain Warning from the shortcut menu for more information about the error.

ii32.gif

code is the error or warning code. Right-click the front panel error out indicator and select Explain Error or Explain Warning from the shortcut menu for more information about the error.

istr.gif

source describes the origin of the error or warning. Right-click the front panel error out indicator and select Explain Error or Explain Warning from the shortcut menu for more information about the error.

MT Apply Pulse Shaping Filter (FSK)

This polymorphic instance applies a pulse-shaping filter to an input stream comprised of FSK-modulated symbols. The VI performs filtering using the specified pulse shaping filter coefficients followed by accumulation on the phase of the information symbols to generate the oversampled FSK-modulated complex baseband waveform. This process is the digital equivalent of continuous-time analog frequency modulation.

Note  With symbol phase continuity set to discontinuous, the VI ignores the pulse shaping filter coefficients parameter. Instead, it generates the baseband waveform after sampling the output of M separate complex exponential oscillators.

MT Apply Pulse Shaping Filter (FSK)

c1dcdb.gif

symbols specifies an array of symbols (comprised of frequency deviations) corresponding to information bits. Wire the symbols parameter of the MT Map Bits to Symbols VI to this parameter.

c1ddbl.gif

pulse shaping filter coefficients specifies an ordered array containing sample-spaced coefficients for the desired pulse-shaping filter. Wire the pulse shaping filter coefficients parameter of the MT Generate Filter Coefficients VI to this parameter. Ensure that the value of the samples per symbol passed to this VI matches the pulse shaping samples per symbol value used to generate the filter coefficients.

Note   When reset? is set to TRUE, there is a transient response of ½ the filter length at the start of the modulated signal, and the returned data is shortened by approximately ½ the filter length. When reset? is set to FALSE, the VI uses data from the previous iteration to eliminate the transient.
ci32.gif

samples per symbol specifies the number of samples per information symbol in the output complex waveform. Multiply this value by the symbol rate to determine the system sampling rate. The default is 16.

cdbl.gif

symbol rate specifies the symbol rate in symbols per second. The default is 1.0.

cenum.gif

symbol phase continuity specifies whether the phase transitions between symbols are continuous.

continuous (0)

Specifies continuous phase transitions between symbols. This is the default value.

discontinuous (1)

Specifies discontinuous phase transitions between symbols, that is, discontinuous phase FSK (DPFSK).

cbool.gif

reset? specifies whether the VI continues pulse-shape filtering using the previous iteration states. The pulse-shaping process is reset on the first call and when reset? is set to TRUE. Set reset? to FALSE to begin pulse shaping at the previous iteration state on subsequent calls. The default is TRUE.

ccclst.gif

error in (no error) can accept error information wired from previously called VIs. Use this information to decide if any functionality should be bypassed in the event of errors from other VIs. Right-click the front panel error in control and select Explain Error or Explain Warning from the shortcut menu for more information about the error.

cbool.gif

status is TRUE (X) if an error occurred or FALSE (checkmark) to indicate a warning or that no error occurred. Right-click the front panel error in control and select Explain Error or Explain Warning from the shortcut menu for more information about the error.

ci32.gif

code identifies the error or warning code. Right-click the front panel error in control and select Explain Error or Explain Warning from the shortcut menu for more information about the error.

cstr.gif

source describes the origin of the error or warning. Right-click the front panel error in control and select Explain Error or Explain Warning from the shortcut menu for more information about the error.

icclst.gif

output phase waveform returns the output pulse-shaped continuous-time phase waveform.

idbl.gif

t0 returns the trigger (start) time of the Y array.

idbl.gif

dt returns time interval between data points in the Y array. The reciprocal of this value is equal to the system sampling rate.

i1dcdb.gif

Y returns the complex-valued signal-only baseband phase waveform.

icclst.gif

error out passes error or warning information out of a VI to be used by other VIs. Right-click the front panel error out indicator and select Explain Error or Explain Warning from the shortcut menu for more information about the error.

ibool.gif

status is TRUE (X) if an error occurred or FALSE (checkmark) to indicate a warning or that no error occurred. Right-click the front panel error out indicator and select Explain Error or Explain Warning from the shortcut menu for more information about the error.

ii32.gif

code is the error or warning code. Right-click the front panel error out indicator and select Explain Error or Explain Warning from the shortcut menu for more information about the error.

istr.gif

source describes the origin of the error or warning. Right-click the front panel error out indicator and select Explain Error or Explain Warning from the shortcut menu for more information about the error.

MT Apply Pulse Shaping Filter (MSK, CPM)

This polymorphic instance applies a pulse-shaping filter to an input stream comprised of MSK- or CPM-modulated symbols. The VI performs filtering using the specified pulse shaping filter coefficients followed by accumulation on the phase of the information symbols to generate the oversampled MSK- or CPM-modulated complex baseband waveform. This process is the digital equivalent of continuous-time analog frequency modulation.

MT Apply Pulse Shaping Filter (MSK)

c1dcdb.gif

symbols specifies an array of symbols (comprised of frequency deviations) corresponding to information bits. Wire the symbols parameter of the MT Map Bits to Symbols VI to this parameter.

c1ddbl.gif

pulse shaping filter coefficients specifies an ordered array containing sample-spaced coefficients for the desired pulse-shaping filter. Wire the pulse shaping filter coefficients parameter of the MT Generate Filter Coefficients VI to this parameter. Ensure that the value of the samples per symbol passed to this VI matches the pulse shaping samples per symbol value used to generate the filter coefficients.

Note   When reset? is set to TRUE, there is a transient response of ½ the filter length at the start of the modulated signal, and the returned data is shortened by approximately ½ the filter length. When reset? is set to FALSE, the VI uses data from the previous iteration to eliminate the transient.
ci32.gif

samples per symbol specifies the number of samples per information symbol in the output complex waveform. Multiply this value by the symbol rate to determine the system sampling rate. The default is 16.

cdbl.gif

symbol rate specifies the symbol rate in symbols per second. The default is 1.0.

cbool.gif

reset? specifies whether the VI continues pulse-shape filtering using the previous iteration states. The pulse-shaping process is reset on the first call and when reset? is set to TRUE. Set reset? to FALSE to begin pulse shaping at the previous iteration state on subsequent calls. The default is TRUE.

ccclst.gif

error in (no error) can accept error information wired from previously called VIs. Use this information to decide if any functionality should be bypassed in the event of errors from other VIs. Right-click the front panel error in control and select Explain Error or Explain Warning from the shortcut menu for more information about the error.

cbool.gif

status is TRUE (X) if an error occurred or FALSE (checkmark) to indicate a warning or that no error occurred. Right-click the front panel error in control and select Explain Error or Explain Warning from the shortcut menu for more information about the error.

ci32.gif

code identifies the error or warning code. Right-click the front panel error in control and select Explain Error or Explain Warning from the shortcut menu for more information about the error.

cstr.gif

source describes the origin of the error or warning. Right-click the front panel error in control and select Explain Error or Explain Warning from the shortcut menu for more information about the error.

icclst.gif

output complex waveform returns the output pulse-shaped continuous-time I/Q baseband waveform.

idbl.gif

t0 returns the trigger (start) time of the Y array.

idbl.gif

dt returns time interval between data points in the Y array. The reciprocal of this value is equal to the system sampling rate.

i1dcdb.gif

Y returns 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.

icclst.gif

error out passes error or warning information out of a VI to be used by other VIs. Right-click the front panel error out indicator and select Explain Error or Explain Warning from the shortcut menu for more information about the error.

ibool.gif

status is TRUE (X) if an error occurred or FALSE (checkmark) to indicate a warning or that no error occurred. Right-click the front panel error out indicator and select Explain Error or Explain Warning from the shortcut menu for more information about the error.

ii32.gif

code is the error or warning code. Right-click the front panel error out indicator and select Explain Error or Explain Warning from the shortcut menu for more information about the error.

istr.gif

source describes the origin of the error or warning. Right-click the front panel error out indicator and select Explain Error or Explain Warning from the shortcut menu for more information about the error.

Details

This VI first upsamples (zero-insertion) the symbols array by a factor equal to the specified samples per symbol value, then filters the symbols stream with the user-specified pulse-shaping filter.

Note   Pulse-shaping filter coefficients can be generated using the MT Generate Filter Coefficients VI or by specifying custom pulse-shaping filter coefficients. The VI does not verify absence of intersymbol interference in custom filter coefficients before applying the pulse-shaping filter.