Fading

Applies to M9484C only.

This capability requires license model N7605AP0C.

After selecting a channel configuration, waveform file (or real-time), and MIMO Order, the Fading graphical user-interface (GUI) presents you with a set of parameters for each signal path. The intended workflow progresses left to right, as available parameter selections are often dependent on what was selected prior (to left).

Custom Profile List for Specified MIMO Order

Custom Profile List for Currently Selected MIMO Order

Correlation Matrix

Doppler Shift

Enable Fading

Enables or disables the fader processing for the specified Group. This control also appears on the Signal Summary screen.

GUI Location	Signals > Signal Summary selection > Fading Setup > Enable Fading
SCPI Command	[:SOURce]:GROup<group>:FADing ON\|OFF\|1\|0 [:SOURce]:GROup<group>:FADing?
SCPI Example	GRO:FAD ON GRO:FAD?
Notes	Setting cannot be set to On when license N7605AP0C is not present or the specified Group’s Configuration is not supported. Supported Configuration Modes are Independent, MIMO2, and MIMO4. Without N7605AP0C, the following error is generated: Attempting to set On will raise error 703, "Feature not supported; Enable Fading unavailable. N7605AP0C is required." Attempts to set a value not allowed will generate the following error: -224,"Illegal parameter value"
Preset	OFF
State Saved	Yes
Initial S/W Revision	A.10.00

MIMO Order

Specifies the desired number of signals within the specified Group to apply fading to. This is the N in NxM MIMO. This parameter also appears on the Signal Summary screen.

GUI Location	Signals > Signal Summary selection > Fading Setup > MIMO Order
SCPI Command	[:SOURce]:GROup<group>:FADing:MORDer 1\|2\|4\|8 [:SOURce]:GROup<group>:FADing:MORDer?
SCPI Example	GRO:FAD:MORD 1 GRO:FAD:MORD?
Notes	Setting cannot be changed without Option 8SG and license N7605AP0C. Attempts to set a value not allowed will generate error: -224,"Illegal parameter value" The value of this setting will affect the available options for Channel Model, Correlation Matrix, and Doppler Shifts.
Preset	1
State Saved	Yes
Initial S/W Revision	A.10.00

Function

Specifies the fader processing for the specified signal and RF Output.

FADE - Applies the selected fading profile to the specified fading path
PASSthrough - Plays the signal with no fading applied
OFF - Equivalent to muting this signal path

GUI Location	Signals > Signal Summary selection > Fading Setup > Function
SCPI Command	[:SOURce]:GROup<group>:SIGNal<signal>:FADing<path>:FUNCtion FADE\|PASSthrough\|OFF [:SOURce]:GROup<group>:SIGNal<signal>:FADing<path>:FUNC?
SCPI Example	GRO:SIGN:FAD2:FUNC FADE ! This sets fading for the first signal in the first group’s output on the second RF Output. GRO:SIGN:FAD2:FUNC?
Notes	Fading (FADing SCPI command parameter) cardinality is based upon the channels configured in the specified group.
Dependencies	Note the group Enable Fading setting supersedes this signal level fading function. If Enable Fading is not turned on for the group, the status of signal level fading function is ignored. When Standard is set to Custom and the profile is not selected, attempting to set Function to Fade issues the error: -221, "Settings conflict; Function cannot be changed to Fade without a selected profile."
Couplings	Case 1 - Function is set to Fade, Standard is a value other than Custom, and the selected profile for custom fading is empty. In this case, if you set Standard to Custom, Function is automatically set to Passthrough. Case 2 - Function is set to Fade, Standard is set to Custom, and the selected profile for custom fading becomes empty. In this case, Function is set to Passthrough.
Preset	PASS
Choices	FADE \| PASSthrough \| OFF
State Saved	Yes
Initial S/W Revision	A.10.00

Standard

Selects the radio standard for the specified fader. The standard models cover propagation environments that allow you to test whether your device meets the performance requirements as defined by the respective standard.

To set the Standard as Custom. the license model N7605APPC is required. When you set the Standard as Custom, you can import and select a custom fading profile for the fading setup.

GUI Location	Signals > Signal Summary selection > Fading Setup > Standard
SCPI Command	[:SOURce]:GROup<group>:SIGNal<signal>:FADing<path>:STANdard NR5G\|LTE\|CUSTom\|NRNTN [:SOURce]:GROup<group>:SIGNal<signal>:FADing<path>:STANdard?
SCPI Example	GRO:SIGN:FAD:STAN NR5G GRO:SIGN:FAD:STAN?
Notes	Fading (FADing SCPI command parameter) cardinality is based upon the channels configured in each group. For M9484C without N7605C with subscription date September 1, 2024, attempting to set NRNTN issues the error: +703,”Feature not supported; NR NTN unavailable, N7605AP0C with subscription date September 1, 2024 is required.”
Preset	NR5G
Range	NR5G\|LTE\|Custom\|NRNTN
State Saved	Yes
Initial S/W Revision	A.10.0
Modified S/W Revision	A.16.0 - Added CUSTom and NRNTN selections

Channel Model

The channel model setting specifies the channel model (simulation type) for the specified fader. There are different models available for each standard. These are listed in detail below.

A channel model is a mathematical representation of the effects of a communication channel through which wireless signals are propagated. The channel model can represent the power loss incurred by the signal as it travels through the wireless medium to the receiver.

GUI Location	Signals > Signal Summary selection > Fading Setup > Channel Model
SCPI Command	[:SOURce]:GROup<group>:SIGNal<signal>:FADing<path>:CMODel STATic\|TDLA10\|TDLA30\|TDLA100\|TDLB100\|TDLC5\|TDLC300\|TDLD10\|TDLD30\|EPA\|ETU\|EVA\|SCEXSCS15K\|SCEXSCS30K\|SCE1SCS15K\|SCE1SCS30K\|SCE3SCS15K\|SCE3SCS30K\|SCE4SCS120k\|SCEYSCS15K\|SCEYSCS30K\|SCEYSCS120K\|SCEZSCS15K\|SCEZSCS30K\|SCE1\|SCE3\|MSCE1\|MSCE2 [:SOURce]:GROup<group>:SIGNal<signal>:FADing<path>:CMODel?
SCPI Example	GRO:SIGN:FAD:CMOD TDLA30 GRO:SIGN:FAD:CMOD?
Notes	Attempts to set a value not allowed for the current instrument configuration and standard will generate error: -224,"Illegal parameter value" Fading (FADing SCPI command parameter) cardinality is based upon the channels configured in each group. The models available for 5G are: STATIC, TDLA10, TDLA30, TDLA100, TDLB100, TDLC5, TDLC300, TDLD10, TDLD30, SCEXSCS15K, SCEXSCS30K, SCE1SCS15K, SCE1SCS30K, SCE1SCS30K, SCE3SCS30K, SCE4SCS120K, SCEYSCS15K, SCEYSCS30K, SCEYSCS120K, SCEZSCS15K, SCEZSCS30K The models available for LTE are: STATIC, EPA, ETU, EVA, SCE1, SCE3, MSCE1, MSCE2 The models available for NR NTN are: TDLA100, TDLC5, SCEXSCS15K, SCEXSCS30K The STATIC channel model is essentially an unfaded signal. The amplitude is constant and there is no doppler shift. The STATIC channel model may be used to simulate the original LOS (Line of sight) signal. Tapped Delay Line (TDL) models are typically more suitable for simplified evaluations, e.g., for non-MIMO evaluations. TDL-A, TDL-B and TDL-C were created to represent three different channel profiles for NLOS (non-line of sight). TDL models usually contain power, delay, and Doppler spectrum information for the taps. Doppler is not explicitly defined, because it is determined by power and angular information combined with array configurations. The EPA (Extended Pedestrian A) channel model uses Rayleigh fading. The ETU (Extended Typical Urban) channel model uses Rayleigh fading. The EVA (Extended Vehicular A) channel model uses Rayleigh fading. NR SCENARIO - These are 5G standard conformance scenarios 1, 3, 4, X, Y, and Z. The "SCS" number at the end indicates the subcarrier channel spacing. LTE SCENARIO - These are LTE standard conformance scenarios 1 and 3, and moving scenarios 1 and 2.
Dependencies	The set of allowed values depends upon the group configuration and standard.
Preset	STATIC
Choices	Static \|TDLA10\|TDLA30\|TDLA100\|TDLB100\|TDLC300\|TDLC5\|TDLD10\|TDLD30\|EPA\|ETU\|EVA\|SCEXSCS15K\|SCEXSCS30K\|SCE1SCS15K\|SCE1SCS30K\|SCESCS15K\|SCE3SCS30K\|SCE4SCS120K\|SCEYSCS15K\|SCEYSCS30K\|SCEYSCS120K\|SCEZSCS15K\|SCEZSCS30K\|SCE1\|SCE3\|MSCE1\|MSCE2
State Saved	Yes
Initial S/W Revision	A.10.0

Custom Profile

Custom Profile capability is available only for M9484C with N7605APPC.

When fading standard is set to Custom, this capability enables the use of custom fading profiles that have been exported from Channel Studio TDL Modeling Tool (*.tdlx).

The instrument maintains a single, global list of custom fading profiles, regardless of which Group the file is imported from. From this list, a profile can be selected for the specified fading path.

Import Profile

Imports a custom fading profile from the specified Channel Studio TDL Modeling Tool (*.tdlx) file. Importing a profile adds the profile to the global list of custom fading profiles by copying the information from the .tdlx file. The .tdlx file name without the tdlx extension is used to name the imported profile. For example, if the 3GPP_5GNR_1x2_TDLA30_5_corrHigh.tdlx is used to import a profile, the imported profile name is 3GPP_5GNR_1x2_TDLA30_5_corrHigh.

There is no query form for this SCPI command.

GUI Location	Signals > Signal Summary selection > Fading Setup > Standard set to Custom > Select > Custom Fading Profile List screen > Import Profile
SCPI Command	[:SOURce]:GROup<group>:FADing:CUSTom:PROFile:IMPort "filename"
SCPI Example	GRO:FAD:CUST:PROF:IMP "C:\abc\11 path Rician.tdlx"
State Saved	No
Initial S/W Revision	A.16.0

Select Profile

Selects the custom fading profile when fading standard is set to Custom.

GUI Location	Signals > Signal Summary selection > Fading Setup > Standard set to Custom > Select > Custom Fading Profile List screen > Select
SCPI Command	[:SOURce]:GROup<group>:SIGNal<signal>:FADing<path>:CUSTom:PROFile <profile name> [:SOURce]:GROup<group>:SIGNal<signal>:FADing<path>:CUSTom:PROFile?
SCPI Example	GRO:SIGN:FAD:CUST:PROF "11 path Rician" GRO:SIGN:FAD:CUST:PROF?
Notes	Available profiles are the imported profiles that match the currently selected MIMO order. Attempting to set an unavailable profile raises the error: -220, "Parameter error; Cannot select an unavailable profile; must be imported and match the currently selected MIMO order. <profile name>"
Couplings	When MIMO Order is changed, the custom profile name is reset to empty to allow you to select a custom profile as per the changed MIMO Order.
Preset	""
State Saved	Yes
Initial S/W Revision	A.16.0

Update Profile

Updates the currently selected profile with the specified .tdlx file. If the profile corresponding to the specified .tdlx file does not exist, a new profile is added.

There is no query form for the command.

SCPI Command	[:SOURce]:GROup<group>:FADing:CUSTom:PROFile:UPDate "filename"
SCPI Example	GRO:FAD:CUST:PROF:UPD "C:\abc\11 path Rician.tdlx"
Couplings	When the currently selected profile is updated with the specified .tdlx file, this profile is continued to be used as the selected profile. Only the contents of the profile are updated with the specified .tdlx file.
State Saved	No
Initial S/W Revision	A.16.20

Delete Profile

Deletes the specified custom fading profile. There is no query form for this SCPI command.

GUI Location	Signals > Signal Summary selection > Fading Setup > Standard set to Custom > Select > Custom Fading Profile List screen > Delete
SCPI Command	[:SOURce]:GROup<group>:FADing:CUSTom:PROFile:DELete <mimo order>,<profile name>
SCPI Example	GRO:FAD:CUST:PROF:DEL "1x1","11 path Rician"
Notes	Attempting to set a value having an invalid format for <mimo order> issues the error: -220,"Parameter error; Invalid MIMO order format: <mimo order>". Attempting to delete the profile which does not exist issues the error: -220, "Parameter error; Specified profile does not exist. MIMO: <mimo order> , Name: <profile name>". Attempting to delete the profile which is currently selected issues the error: -200, "Execution error; Profile cannot be deleted while currently in use; MIMO: <mimo order> , Name: <profile name> "
Range	<mimo order>: string of "MxN" format where M and N are positive integers <profile name>: string
State Saved	No
Initial S/W Revision	A.16.0

Custom Profile List

Remote Query only command.

Returns the list of imported custom fading profiles as a string of comma-separated values of MIMO orders and corresponding imported profile names. For example, if imported profiles are as follows:

"Profile A" having 1x1 MIMO order
"Profile B" having 2x1 MIMO order
"Profile C" having 4x2 MIMO order

The string returned for the above list of profiles is "1x1","Profile A","2x1","Profile B","4x2","Profile C".

SCPI Command	[:SOURce]:GROup<group>:FADing:CUSTom:PROFile:LIST?
SCPI Example	GRO:FAD:CUST:PROF:LIST?
State Saved	No
Initial S/W Revision	A.16.0

Custom Profile List for Specified MIMO Order

Remote Query only command.

Returns the list of imported custom fading profiles for the specified MIMO order. This command returns a string of comma-separated values for custom fading profile names.

SCPI Command	[:SOURce]:GROup<group>:FADing:CUSTom:PROFile:LIST:MORDer? <mimo order>
SCPI Example	GRO:FAD:CUST:PROF:LIST:MORD? "1x1"
Notes	Attempting to set a value having an invalid format for <mimo order> issues the error: -220,"Parameter error; Invalid MIMO order format: <mimo order>".
Range	<mimo order>: string of "MxN" format where M and N are positive integers
State Saved	No
Initial S/W Revision	A.16.0

Custom Profile List for Currently Selected MIMO Order

Remote Query only command.

Returns the list of imported custom fading profiles for the currently selected MIMO order. This command returns a string of comma-separated values for custom fading profile names.

SCPI Command	[:SOURce]:GROup<group>:FADing:CUSTom:PROFile:LIST:MORDer:SELected?
SCPI Example	GRO:FAD:CUST:PROF:LIST:MORD:SEL?
State Saved	No
Initial S/W Revision	A.16.0

Correlation Matrix

The correlation matrix setting specifies the correlation level in spatial paths to use between the RF Outputs in the instrument group. In general, the higher the correlation between channels, the worse the "channel disparity". Because MIMO is banking on spatial differences in the channel to increase throughput, the higher correlated models represent worse conditions and subsequently lower throughput.
The correlation matrix settings are related to 3GPP standards. 5GNR base station conformance tests have correlations defined by 38.141-1 document in Annex G.

GUI Location	Signals > Signal Summary selection > Fading Setup > Correlation Matrix
SCPI Command	[:SOURce]:GROup<group>:SIGNal<signal>:FADing<path>:CMATrix NONE\|LOW\|MED\|MEDA\|HIGH\|XPLOW\|XPMED\|XPMEDA\|XPHIGH [:SOURce]:GROup<group>:SIGNal<signal>:FADing<path>:CMATrix
SCPI Example	GRO:SIGN:FAD:CMAT MEDA GRO:SIGN:FAD:CMAT?
Notes	Attempts to set a value not allowed for the current instrument configuration and channel model will generate error: -224,"Illegal parameter value" Fading (FADing SCPI command parameter) cardinality is based upon the number of channels configured in the specified group. XP is an abbreviation for cross polarization. The "XPLOW\|XPMED\|XPMEDA\|XPHIGH" settings are specifically calling out models that account for antenna cross-polarization in some capacity. It serves the same function as spatial correlation considerations, though it is calculated specifically for antenna effects.
Dependencies	The set of allowed values depends upon the group configuration and channel model. For single RF output group configurations, NONE is the only available selection.
Preset	NONE
Choices	None \| LOW \| MED \| MEDA \| HIGH \| XPLOW \| XPMED \| XPMEDA \| XPHIGH
State Saved	Yes
Initial S/W Revision	A.10.0

Doppler Shift

This parameter specifies the doppler shift for the given fader. Doppler shift describes the changes in frequency of a propagated wave produced by a moving source with respect to an observer. Waves transmitted by an object traveling toward an observer get compressed resulting in a higher frequency as the source approaches the receiver.

GUI Location	Signals > Signal Summary selection > Fading Setup > Doppler Shift
SCPI Command	[:SOURce]:GROup<group>:SIGNal<signal>:FADing<path>:DSHift <freq> [:SOURce]:GROup<group>:SIGNal<signal>:FADing<path>:DSHift?
SCPI Example	GRO:SIGN:FAD:DSH 75 !Sets the fader doppler shift to 75 Hz GRO:SIGN:FAD:DSH?
Notes	Fading (FADing SCPI command parameter) cardinality is based upon the channels configured in each group. There are limited sets of values for the current instrument configuration, standard, correlation matrix. The closest available value will be used from the fading profiles installed on the instrument.
Dependencies	The set of allowed values depends upon the group configuration, channel model, and correlation matrix.
Preset	0 Hz
State Saved	Yes
Min	0 Hz
Max	The min, max, and resolution are based upon the discrete values inside the fading profiles installed on the instrument. In other words, the actual value used will be quantized by the possibilities present. The preset value above is the doppler shift value in the "STATIC" channel model, which is the preset channel model.
Initial S/W Revision	A.10.0