Measurements: Custom OFDM

This topic describes the Signal Optimizer's default Favorite Settings for the Custom OFDM measurement format.

Custom OFDM

Name

Enter the name of the resource block.

Description

Enter a description of this measurement.

Signal Coupling

When enabled (default state), this parameter conveniently couples the measurement definition to the Selected Signal. Coupled parameters may update when Download All Signals or Run Acquisition executed. This parameter is available under Advanced for all measurement types. It does not appear under Favorites unless manually added.

Selected Signal

Select the signal definition to be applied when Signal Coupling is enabled. This parameter is available under Advanced for all measurement types. It does not appear under Favorites unless manually added.

Frequency

Frequency Coupling

Enable or disable coupling of Measurement Center Frequency and Measurement Span to Analyzer Hardware Center Frequency and Analyzer Span.

Center Frequency Offset

Enter offset to apply to automatically determined measurement Center Frequency setting when Frequency Coupling is enabled.

Span Scale Factor

Enter scale factor to apply to automatically determined measurement frequency span setting when Frequency Coupling is enabled.

Center Frequency

Enter measurement center frequency when Frequency Coupling is disabled. When Frequency Coupling is enabled, measurement center frequency is automatically determined by Analyzer Hardware Center Frequency and Center Frequency Offset settings.

Measurement Span

Enter measurement frequency span (bandwidth) when Frequency Coupling is disabled. When Frequency Coupling is enabled, measurement span is automatically determined by Analyzer Hardware Span and Span Scale Factor settings.

Auto Frequency Step

Enable automatic adjustment of Frequency Step value.

Resolution Bandwidth

Displays the measurement resolution bandwidth (RBW).

Frequency Points

Displays the number of unaliased frequency points to display. Should be set to p2/1.28 + 1, where p2 is a power of 2.

Auto Frequency Points

Enable automatic adjustment of Frequency Points value to allow for a wider range of Resolution Bandwidths (and therefore time record lengths).

Custom OFDM Analysis Settings

FFT Length

Enter the FFT length used for OFDM transmission. The value must be even. Usually the value is a power of two.

Range: 4 - 16384

Guard Interval

Enter the guard interval (also called cyclic prefix), specified as a fraction of the OFDM FFT length. The value is unitless (not percent). The value is ignored if Modulation Scheme is FBMC.

Guard Lower Subcarriers

Enter the number of lower guard subcarriers. These subcarriers will be ignored - they will not appear in any results, the modulation and resource type are undefined.

Range: 0 - FFT Length / 2

Guard Upper Subcarriers

Enter the number of upper guard subcarriers. These subcarriers will be ignored - they will not appear in any results, the modulation and resource type are undefined.

Range: 0 - FFT Length / 2

Display EVM in Percent

Enable or disable display of EVM values in percent. When disabled, EVM values are displayed in dB.

Equalizer Use Data

Enable or disable use of data subcarriers to help train the equalizer.

Equalizer Use Pilots

Enable or disable use of pilot subcarriers to help train the equalizer.

Equalizer Use Preamble

Enable or disable use of preamble subcarriers to help train the equalizer.

Pulse Search Enable

Enable or disable whether to use a burst (pulse) search to locate the start of the signal to analyze.

Modulation Scheme

Select the modulation scheme for the analyzed signal.

Choices: OFDM | F-OFDM | FBMC

Multiple Access Scheme

Select the multiple access scheme for the analyzed signal.

Choices: None | SCMA | NOMA

OFDM System Sample Frequency

Enter the OFDM FFT sample rate.

Result Length

Enter the number of symbols to be processed during demodulation.

Search Length

Enter the amount of data over which a search is performed when Pulse Search is enabled.

Synchronization Mode

Select the synchronization mode used when synchronizing to the signal. The value is ignored and Time Correlation is used if Modulation Scheme is set to FBMC.

Choices: Time Correlation | Cyclic Prefix

Time

Length

Enter the measurement main time length.