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Custom Modulation

Waveform

Custom Modulation

Basic

Required License Version Date

User Defined Sample Rate

Oversampling Ratio

Sample Rate

Number of Frames

Total Sample Points

Waveform Length

Mirror Spectrum

Marker

Marker 1 Source

Marker 2 Source

Marker 3 Source

Marker 4 Source

Crest Factor Reduction

Crest Factor Reduction

Target PAPR

Max Iteration

Cancelling Percent

Block Size

Filter Mask

Multicarrier

Multicarrier Enabled

Number of Carriers

Carrier Phases

Payload Data Offset

Frequency Offsets

Power Offsets

Correction

Equalization Enabled

VSA Equalization Data File

Equalization Bandwidth

Routing

Group

Signal

Graph View

Custom Modulation

Choices: Custom IQ

Select the custom modulation format of the waveform. The tree view nodes and associated properties in the parameter view change with each selection.

• Custom IQ: Single carrier signal with user-defined IQ constellations.

Basic

Required License Version Date

User Defined Sample Rate

Enable or disable the User Defined Sample Rate. If enabled, the OverSamplingRatio will not be used.

Oversampling Ratio

Enter the oversampling ratio of the waveform. The Total Sample Points is automatically determined based on the oversampling ratio.

Oversampling Ratio is not applicable for Radar signal.

Sample Rate

Set the value of user defined sample rate if user defined sample rate is enabled.

Number of Frames

Enter the number of frames included in the waveform.

Total Sample Points

Displays the generated waveform length in sample points. This value is read-only and automatically updates with changes to oversampling ratio, number of frames, and custom modulation type.

Waveform Length

Displays the generated waveform length in seconds. This value is read-only and automatically updates with changes to oversampling ratio, number of frames, and custom modulation type.

Mirror Spectrum

Enable or disable the mirror spectrum (inverted IQ) for the waveform.

Marker

Marker 1 Source

Choices: Waveform Start | Frame Start | RF Blanking Control | RF ALC Control

Default: Waveform Start

Select the source for marker 1.

• Waveform Start: It indicates the beginning of the waveform.

• Frame Start: It indicates the beginning of each frame in the waveform.

• RF Blanking Control: It indicates the burst part in the waveform.

• RF ALC Control: It indicates the part used for ALC control in the waveform.

Marker 2 Source

Choices: Waveform Start | Frame Start | RF Blanking Control | RF ALC Control

Default: Frame Start

Select the source for marker 2.

• Waveform Start: It indicates the beginning of the waveform.

• Frame Start: It indicates the beginning of each frame in the waveform.

• RF Blanking Control: It indicates the burst part in the waveform.

• RF ALC Control: It indicates the part used for ALC control in the waveform.

Marker 3 Source

Default: RF Blanking Control

Displays the source for marker 3. RF Blanking Control is always used as Marker 3 source.

Marker 4 Source

Default: RF ALC Control

Displays the source for marker 4. RF ALC Control is always used as Marker 4 source.

Crest Factor Reduction

Crest Factor Reduction

Enable or disable the crest factor reduction for the waveform. When enabled, peak cancellation algorithm is used to subtract a weighted version of the cancellation pulses from the original input signal. It strikes a balance between the out-of-band emission and in-band waveform quality when reducing the PAPR of the signal.

Target PAPR

Set the PAPR value to achieve after crest factor reduction.

Max Iteration

Specify the maximum times of iteration. With the increasing of iteration, the PAPR value should converge to a steady level.

Cancelling Percent

Specify the percentage that the cancellation pulses can be removed.

Block Size

Block is the range that a single cancellation pulse can be identified. If the waveform length is L, and the block size is B, then the number of blocks is N=floor(L/B)+1. Therefore, there will be N pulses at most to be removed.

Filter Mask

Opens the Filter Mask for Crest Factor Reduction editor to define a filter response in frequency domain. In the table, the frequency points must be entered with an order of increasing frequency in unit of MHz, and its corresponding amplitude is in unit of dB. When generating this filter mask, the frequency points between the specified points are linearly interpolated. When signal symbol rate is changed, this table will be automatically updated. User may need to adjust the mask manually to fit the signal bandwidth.

The format of Filter Mask string, appearing in the parameter field, is: <freq 1>,<amp 1>; <freq 2>,<amp 2>;….<freq n>,<amp n>.

Multicarrier

Multicarrier Enabled

Enable or disable the multicarrier mode for waveform generation, when enabled, waveform which has at least one carrier will be generated, the count of carriers is decided by the frequency offsets definition, When disabled, waveform with only one carrier will be generated.

Number of Carriers

Indicate how many carriers has been defined and is a read only value.

Carrier Phases

Define the initial phase of every carrier when multicarrier mode enabled. “Fixed” means all carriers has same initial phase which is zero; “Random” means initial phase of every carrier is random value.

Payload Data Offset

Define the payload data offset between each carriers when multicarrier mode enabled, it is only applied for Custom IQ.

Frequency Offsets

Opens a window where you can define the frequency offset of every carrier for multicarrier mode. There are three methods that can be used:

• To configure by individual carrier, use "," as delimiter. For example: "1MHz,2MHz,10MHz,20MHz" as frequency offsets for 4 carriers.

• To configure by a range of carriers, use ":" to define the start frequency offset of first carrier, frequency step and the count of multi carriers. For example,"1MHz:2MHz:5" means 5 carriers offsets defined as "1MHz,3MHz,5MHz, 7MHz,9MHz"

• Above 2 ways can be used by combination. For example: "1MHz:2MHz:5, 20MHz,30MHz"

Each frequency value can be used with unit (K, KHZ, M, MHZ, G, GHZ, HZ). When the value is without unit, the default unit HZ will be used. For example, you can input it as "2K, 4MHz" or "2, 4" . And the unit is case insensitive.

Power Offsets

Opens a window where you can define the power offset of every carrier for multicarrier mode. There are three methods that can be used:

• To configure by individual power offsets, use "," as delimiter. For example: "0,-1,0,-1" means the power offset for 1st carrier is 0 dB , -1dB for 2nd carrier, 0dB for 3rd carrier and -1dB for 4th carrier.

• To configure by a range of power offsets, use ":" to define the power offset of first carrier, power offset step and the count of multi carriers. For example,"0:-1:5" means "0,-1,-2, -3,-4".

• Above 2 ways can be used by combination. For example: "0:-1:5, -8,-9".

The count of final power offsets definition is also decided by value of frequency offsets, because they need to have the same count.

Unit is dB.

Correction

Equalization Enabled

Coupling: Coupled with VSA Equalization Data File and Equalization Bandwidth.

Enable or disable equalization for waveform generation. When enabled, equalization will be applied to the generated waveform according to the EQ Data from VSA.

VSA Equalization Data File

Choices: The file type should be .csv

Load the EQ data file from VSA. You can type the directory of the EQ file or browse it in your computer.

Equalization Bandwidth

The equalization will be performed within this bandwidth.

Routing

Group and Signal settings determine where the specific waveform of Custom Modulation is played. The waveform file name will have a _G#S# suffix based on the routing configuration. So, you can specify different Group/Signal to generate/playback/edit this waveform.

Group

Assign the signal group number.

Signal

Assign the signal number.

Graph View

The graph view displays several different representations of the generated waveform.

For more information, see Graph View.

Related Topics

Carrier - Custom IQ

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