Choice: On |Off
Default: On
Double-click or use the drop-down menu to control the operating state of the carrier.
Displays the selected carrier format. (See Format in the Menu Bar and Tool Bar topic.)
Range: Depends on instrument and waveform settings
Default: 0.000000 Hz
Set the frequency offset for the carrier relative to the signal generator’s frequency setting. The valid range will be different for every format due to the different oversampling ratios.
For example, for two-carrier configurations, set the center frequency of signal generator to 1 GHz, and make the two carriers distributed on the both sides of the center frequency with 5 MHz offset each. Therefore, the actual frequency of each carrier would be 1 GHz + 5 MHz and 1 GHz - 5 MHz respectively.
Range: 0 to 359 degrees
Set the initial phase of the carrier.
Range: -50 to 0 dB
Set the carrier’s power relative to the signal generator’s amplitude setting.
Range: 1 to 1000
Default: 1
Gets or sets the number of PLC frames to be generated. One PLC frame has 128 OFDM symbols.
Range: 1 MHz to 500 MHz
Default: 204.8 MHz
Sets or gets the sample rate of DOCSIS 3.1 Downstream carrier. Set it to be 204.8 MHz for standard signal. For multicarrier case, this parameter is read-only and determined by the first carrier.
Choice: 4096 | 8192
Default: 4096
Gets or sets the FFT Size for the OFDM. Double-click or use the drop-down menu to select the FFT size for the OFDM signal. For multicarrier case, this parameter is read-only and determined by the first carrier.
Choices: 50 kHz | 25 kHz
Default: 50 kHz
Displays the subcarrier spacing for the OFDM. This parameter is always read-only and determined by FFT Size.
Choice: 0.9375 us (192*Tsd) | 1.25 us (256*Tsd) | 2.5 us (512*Tsd) | 3.75 us (768*Tsd) | 5 us (1024*Tsd)
Default: 0.9375 us (192*Tsd)
Gets or sets the cyclic prefix points for the OFDM. Double-click or use the drop-down menu to select the cyclic prefix time (points) for the OFDM signal.
For multicarrier case, if this carrier is not first carrier, Cyclic Prefix will be read-only. And the value is determined by the first carrier settings.
Choice: 0 us (0*Tsd) | 0.3125 us (64*Tsd) | 0.625 us (128*Tsd) | 0.9375 us (192*Tsd) | 1.25 us (256*Tsd)
Default: 0.625 us (128*Tsd)
Gets or sets the windowing roll-off points for the OFDM signal. Double-click or use the drop-down menu to select the windowing roll-off time (points) for the OFDM signal.
Click
in the right side of the cell to open the 
Multi-path Channel
configuration window.The default is OFF and you can change Multi-path Parameter” to User Defined and set the paths in the table.
User Defined provides a more flexible way configuring each path's attenuation ρ, relative delay τ and phase shift from scattering θ.
You can edit the parameters values in the table directly. Alternatively, click on the Open button, and select a fading file (*.fading) previously configured.
When you finished editing the user defined parameter configuration, click on Save button to make a copy.
A multi-path channel which contains up to 20 paths can be set according to your test requirements.
Display the attenuation of the i'th path.
If Attenuation of all paths are zero, there will be an error when you click OK to close this dialog.
Displays the ralative delay of the i'th path.
When this valus is too large, there will be an out-of-memory exception that ask you to decrease it.
Displays the phase shift of the i'th path.
This is a radian value, so 2*pi has the same meaning with 0.
Choice: On | Off
Default: Off
Coupling: When Tilted Channel is off (default), the Tilt per Subcarrier will not be activated.
Get/Set whether tilted channel is enabled.
See also, Generating a Tilt Spectrum for DOCSIS3.1.
Range: -1dB to 1dB
Resolution of tilt: 0.0001dB
Default: 0 dB
Coupling: When Tilted Channel is off (default), the Tilt per Subcarrier will not be activated.
Get/Set the tilt amplitude per subcarrier in dB.
See also, Generating a Tilt Spectrum for DOCSIS3.1.
Range: -102.4 MHz to 102.4 MHz
Default: 0 Hz
Sets or gets the central frequency shift value. This is always used by some cases that the valid subcarriers has large bias compared to central frequency. So signal generator frequency is shifted to make valid subcarriers around signal generator frequency.
The range of this parameter is determined by exclusion band, down-sample ratio.
Displays the frequency of the first subcarrier. This parameter is read-only and calculated by the frequency of the signal generate and Central Frequency Shift.
Subcarrier Zero Frequency = Signal Generator Frequency – Central Frequency Shift – Sample Rate / 2
Sets or gets the exclusion bands. The bands are separated by "," and surrounded by "[" and "]". For example, [0,1599],[2496,4095] means 2 bands, one is from subcarrier 0 to subcarrier 1599, the other is from subcarrier 2496 to subcarrier 4095.
Exclusion bands will be checked when changed or before generation. The rules are as follows:
Exclusion bands can not overlap.
The upper subcarrier index must not smaller than the lower subcarrier. For example, “[599,100]” is not a valid setting.
Exclusion band can’t overlap with Continuous Pilot
Exclusion band can’t overlap with PLC subcarriers.
Range: 1 to 8192
Default: 896
Gets the number of active Subcarirers of DOCSIS3.1 Downstream carrier. Active means not in the exclusion bands.
This parameter is always read-only. The value is determined by FFT Size and Exclusion Bands.
Choices: Defined by Parameter M | User Input
Default: Defined by Parameter M
Sets or gets the method that how to define continuous pilot positions.
Range: 48 to 120
Default: 48
Sets the M parameter to generate continuous pilot positions.
M is only visible when Continuous Pilot Placement is Defined by Parameter M.
Sets or gets the Continuous Pilot Positions. When Continuous Pilot Placement is set to Defined by M Parameter, this parameter is read-only and the value is calculated by M. The pilot positions is separated by ",".
When Continuous Pilot Placement is set to Defined in PLC Message, the value of Continuous Pilot Positions must follow these rules:
Continuous Pilot can’t overlap with Exclusion Bands
Continuous Pilot can’t overlap with PLC subcarriers.
Range: 25 KHz to 192 MHz
Default: 44.8 MHz
Gets the Active Signal Bandwidth of DOCSIS3.1 Downstream carrier.
This parameter is always read-only. The value is determined by FFT Size and Exclusion Bands.
Choices: None | 15/16 | 1/2 | 1/4 | 1/8
Default: 1/2
Double-click or use the drop-down menu to select downsampling ratio for the DOCSIS 3.1 Downstream carrier. The valid choices is determined by Active Signal Bandwidth. Downsampling is used for narrow band signal generators to play signals with narrow active signal bandwidth.
Range:
0 to 4800 for FFT Size = 4096
0 to 8176 for FFT Size = 8192
Default: 2084
Sets or gets the PLC Start Index of DOCSIS 3.1 Downstream carrier. This parameter determines the position of PLC subcarriers and scattered pilot subcarriers.
The valid value is defined by FFT Size and Exclusion bands.
Range: 0 to 2^55 - 1
Default: 0
Sets or gets the Time-stamp transmitted in PLC payload. The unit is 1/10240000 second.
Range: 8 to 16
Default: 8
Gets the Number of PLC Subcarriers.
This parameter is read-only and determined by FFT Size.
Range: 2.6 ms to 250 ms
Default: 2.6 ms
Gets or sets the OCD/DPD interval. It should be integral multiple of the PLC frame time. It is read-only when Number of PLC Frames is 1.
The valid value for OCD/DPD Interval is defined by some OFDM parameters including FFT Size and Cyclic Prefix.
Gets or sets the payload of PLC subcarriers. Click the right button to open the PLC payload dialog to set the payload of PLC.
A pop up window will pop out.
- the PLC payload is based on the current configuration and is encoded according to the standard.
- the PLC payload uses the text in the edit window and maps it to a 16-QAM modulation format.
- the PLC payload uses the text in the edit window and encodes it according to the standard.
Range: 0 to 255
Default: 0
Gets or sets the Downstream Channel ID for OCD and DPD.
Choices: QPSK | 16 QAM | 64 QAM
Default: 64 QAM
Sets or gets the modulation type of NCP subcarriers.
Range:
1 to 32 for FFT Size = 4096
1 to 16 for FFT Size = 8192
Range : 1 to 32
Default: 32
Sets or gets the Time interleave Depth for data subcarriers.
Range : 1 to 32
Default: 1
Gets the number of profiles as the data payload.
Gets or sets the profile look-up sequence for the data payload. This is a string composed of A to P.
This is read-only when Number of Profiles is 1.
