MT Modulate FM

Performs frequency modulation on an RF carrier wave according to a baseband information signal passed to the message signal parameter. This node performs signal processing on data and operates independently of hardware settings. Use this node in both simulated and hardware-equipped applications.

1378

Inputs/Outputs

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message signal

Message signal used to modulate the carrier wave.

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FM deviation

The desired frequency deviation, in hertz (Hz), of the frequency-modulated signal returned in the FM modulated waveform parameter.

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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

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reset?

A Boolean that determines initialization of internal VI states. The modulation process involves an integration operation.

TRUE The initial state of the integration is set to zero at each call to this node.
FALSE The integration begins in the final state from the previous call. Use this option when the current block of I/Q data is contiguous with the preceding block of I/Q data.

Default value: FALSE

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FM modulated waveform

The baseband signal data and the complex envelope of the frequency-modulated signal.

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t0

The trigger (start) time of the signal data.

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dt

Time interval between data points in the signal data.

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Y

The complex-valued time-domain data array. The real and imaginary parts of this complex data array correspond to the in-phase (I) and quadrature-phase (Q) data, respectively.

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error out

Error information.

The node produces this output according to standard error behavior.

Standard Error Behavior

Frequency-Modulated Wave Formula

The output frequency-modulated (FM) wave is described by the following equation:

F M = e i ( 2 π f r e q u e n c y D e v i a t i o n f s ∫ t ( ( m e s s a g e S i g n a l ) ⅆ τ +   c a r r i e r P h a s e ) ) F M = e i ( 2 π f r e q u e n c y D e v i a t i o n f s ∫ t ( ( m e s s a g e S i g n a l ) ⅆ τ +   c a r r i e r P h a s e ) )

This node sets carrierPhase in the preceding equation to 0. To adjust the carrier phase, use the initial phase parameter of MT Upconvert Baseband (Real) or MT Upconvert Baseband (Complex).