8. Real-time Noise Setup

The following figure is a composite of all supported instruments, so some parameters may not apply to your instrument.

If an instrument does not have Real-time Noise capabilities, the noise effect does not work.

Real-time Noise

Choice: On | Off

Default: Off

Double-click or use the drop-down menu to enable or disable adding real-time, non-repeating additive white Gaussian noise (AWGN) to the carrier being modulated by the waveform being played.

On – enables the addition Real-time Noise.
Off – disables the addition of Real-time Noise.

Carrier to Noise Ratio

Range: –100 dB to 100 dB

Default: 0 dB

Enter the noise power to be applied to a waveform. The carrier power is defined as the total modulated signal power before noise power is added. The noise power is the in-channel noise power. A positive value makes C larger than N.

Carrier Bandwidth

Range: 0.001 to 80.000 MHz

Default: 1.0 Hz

Displays the carrier bandwidth. This is the same as the bandwidth of the target carrier.

Carrier Bandwidth Auto

Choice: Auto | Manual

Default: Manual

Sets whether the Carrier Bandwidth is automatically set by the software or set manually using the Carrier Bandwidth parameter.

When set to Auto, the carrier bandwidth is as follows:

3.84 MHz (single carrier signal)
3.84 MHz x Number-of-Carriers (multi-carrier signal)

Noise Bandwidth Factor

Range: 1–2

Default: 1

Displays the flat noise bandwidth factor for the applied real-time noise.

When the Sample Clock is < 50 MHz, the Noise Bandwidth Factor adjusts the RF flat noise bandwidth to be either at least 0.8 times the sample rate for a bandwidth factor of 1, or 1.6 times the sample rate if the bandwidth factor is 2.

When the Sample Clock is > 50 MHz, noise cannot be enabled if the Noise Bandwidth Factor is 2. Any oversampling in a waveform will effectively make the noise bandwidth be that many times wider than the signal bandwidth.

The Noise Bandwidth is calculated as follows:

The noise bandwidth is at least 0.8 * [ARB Sample Clock] * [Noise Bandwidth Factor]

This parameter is not available with all instrument model numbers and may be grayed out.

Noise Bandwidth

Range: 0.001 to 100.000 MHz

Default: 1.0 Hz

Set or change the noise bandwidth (MHz).

This parameter is not available with all instrument model numbers and may be grayed out.