Signals: Multi Tone

This topic describes the Signal Optimizer's default Favorite Settings for a Multi-Tone signal format.

Signal Information

Sample Rate

Display the sample rate of the signal. This value is read-only and will be autotmaically calculated from symbol rate and over sampling rate.

Sample Points

Display the number of sample points in the waveform. This value is read-only and will be automatically updated with waveform setting change. Waveform length is directly related to the oversampling ratio value selected. (Increasing the oversampling ratio increases the total sample points.)

Signal Length

Display the waveform length in seconds. This value is read-only and will be automatically updated with waveform setting change.

Signal Setup

Multi Tone Settings

Number of Tones (each side of Fc)

There is always a tone at Fc (which may be suppressed). This parameter sets how many tones are generated on each side of the tone at Fc.

For example: If Number of Tones (each side of Fc) setting is 75, and Suppressed Tones is None, then the total number of active tones generated would be 75 + 1(Fc) + 75 = 151 tone comb.

Tone Spacing

Specify the tone frequency separation value in Hz to be used for generating the Multi Tone signal.

Phase Distribution

Select the phase distribution to used across the multiple tone set.

Choices: Random | Constant | Parabolic

Suppressed Tone

It is common in OFDM modulation for the tone at Fc, or the three tones at Fc and Fc +/- 1 to be unused and suppressed because of the negative impact on these tones from any DC component in the modulation.

This parameter allows the use to create multitone combs with similarly suppressed center tone(s).

Single Sided

When enabled this suppresses all the negative frequency tones. The reported Active Tone Count and Active Tone OBW values will update to reflect the reduced number of active tones.

Active Tone Count

The total number of active tones to be generated, after accounting for any suppressed tones.

For example: If Number of Tones (each side of Fc) setting is 75, Suppressed Tones is None and Single Sided = False, then the total number of active tones generated would be 75 + 1(Fc) +75 = 151 tone comb.

If Suppressed Tones is Tone at Fc, then the total number of active tones generated would be 75 + 0(Fc) + 75 = 150 tone comb.

Active Tone OBW

Reports the frequency delta from the lowest active multi tone frequency to the highest multi tone frequency, after accounting for any suppressed tones.

For example: If Number of Tones (each side of Fc) setting is 75, Suppressed Tones is Tone at Fc, Single Sided = False, and Tone Spacing is 0.5 MHz, then the total number of active tones generated would be 75 + 1(Fc) +75 = 151 tone comb.

For this example the reported Active Tone OBW delta frequency between the lowest and highest active tone frequencies would be 0.5 MHz x 150 = 75 MHz.