Channel (5G NR/5G-Advanced)

The Channel summary panel contains higher-level physical channel parameters and physical channel summary information.

Downlink

Allocation and Symbol Auto Detection - Performs Power-based auto detection for the SS/PBCH, PDSCH Physical Downlink Shared Channel and PDCCH physical channels.

SS/PBCH - Enables or disables SS/PBCH auto-detection. When enabled, the 5G NR demodulator detects the signal's SS/PBCH parameters except for Power Boosting (Power Boosting levels are needed for proper SS/PBCH Auto Detection). Except for Power Boosting, the SS/PBCH panel's settings are grayed out because the autodetected parameters are being used rather than the manual settings.

When SS/PBCH Auto Detection is enabled, results data for the detected SSBs appears in the (CCn) Summary Table.

Default: Disabled

PDSCH - Enables or disables PDSCH auto-detection.

PDSCH auto-detection is a BETA feature for the software.

The PDSCH auto-detection feature attempts to evaluate statistical conditions of the analyzed time waveform to deduce the per-slot/per-RB presence of PDSCH transmissions. This approach works for many PDSCH allocation types. Specifically, single allocation PDSCH transmissions (with or without SSB) with high SNR Signal-to-Noise Ratio are good candidates for this technique.

Certain scenarios listed below are not compatible with this technique:

Measurements with >1 input channel
Presence of PDCCH signals without active SS/PBCH signals
Presence of CSI channel state information-RS signals without active SS/PBCH signals
Signal to noise levels below 25 dB (for QPSK Quadrature phase shift keying data)
Presence of PTRS (frequently used in FR2 configurations). If present, the measurement will return high PDSCH EVM Error vector magnitude (EVM): A quality metric in digital communication systems. See the EVM metric in the Error Summary Table topic in each demodulator for more information on how EVM is calculated for that modulation format..

You must enter all parameters in the Carrier panel and BWP panel correctly before Auto Detection can work. See Understanding 5G NR Auto Detection for more information.

Default: Disabled

PDCCH - Enables or disables PDCCH auto-detection.

PDCCH auto-detection is a BETA feature for the software.

When PDCCH Auto-detection is turned on, PDCCH Decoding is automatically enabled and set to Decoded TB, and Payload Size, DCI Format, Aggregation Level and Candidate Index are automatically detected.

PDCCH Auto-detection follows UE User Equipment (e.g. cell phone) protocol according to the standard, where the CORESET and Search Space configurations are transmitted to the UE through the MIB or PDSCH. With this information along with the RNTI, the UE searches the active DCI within the Search Space for PDCCH information.

You must configure the CORESET and Search Space before PDCCH auto-detection can work.

Default: Disabled

Copy Auto to Manual (SS/PBCH only) - Copy Auto to Manual becomes active when SS/PBCH Auto Detection is enabled and once the autodetection has finished identifying the correct parameter values. You can click Copy Auto to Manual to populate the manual SS/PBCH settings with the values acquired by the autodetection process. Disable Auto Detection to reactivate the SS/PBCH manual settings.

Reference Bits

PDSCH IQ Ref - Selects the source of the reference constellation points for PDSCH EVM calculation.

Demod - Reference constellation points are obtained from demodulation. Bit Error Rate (BER Bit Error Ratio - A ratio of the number of errors to data bits received on a digital circuit.) calculations are not perfomed with this selection.

NR-TM PN23 DL Down Link (forward link: from base station to cell phone)- Reference constellation points use a PN23 sequence as specified in section 4.9.2.3.2 of 3GPP TS Technical Specification 38.141, and the PN 1) part number, or 2) packet number sequence is mapped to all Downlink slots and symbols in each frame. The PDSCH data must use the same PN23 sequence and the Analysis Start Boundary should be set to Frame for this to work. Bit Error Rate (BER) calculations are perfomed with this selection, and the Error Bits, Total Bits, BER (%) metrics appear in the Slot Summary trace.

All 0s - Uses all 0s as the PDSCH reference. The PDSCH data must be all zeros for this work. Bit Error Rate (BER) calculations are perfomed with this selection, and the Error Bits, Total Bits, BER (%) metrics are reported in the Slot Summary trace.

NR-TM PN23 All - Reference constellation points use a PN23 sequence as specified in section 4.9.2.3.2 of 3GPP TS 38.141, and the PN sequence is mapped to all slots and symbols over the whole frame, regardless whether it is downlink or uplink slot/symbols. The PDSCH data must use the same PN23 sequence and the Analysis Start Boundary should be set to Frame for this to work. Bit Error Rate (BER) calculations are perfomed with this selection, and the Error Bits, Total Bits, BER (%) metrics appear in the Slot Summary trace.

Default: Demod

Synchronization Config

If SSB is present in the transmitted signal and Cell ID auto detection is selected, VSA always syncs to SSB, regardless of the Sync Source setting since the Cell ID can only be detected from SSB.

Sync Source - Selects the frame synchronization source.

Auto - The VSA software tries to select the best synchronization source for the measurement with the following priority:

SSB

PDSCH DMRS

PDCCH DMRS

CSI-RS

SSB - Uses the SSB specified by Source ID as the synchronization source.

PDSCH DMRS - Uses the PDSCH DMRS specified by Source ID as the synchronization source.

PDCCH DMRS - Uses the PDCCH DMRS specified by Source ID as the synchronization source.

CSI-RS - Uses the CSI-RS specified by Source ID as the synchronization source. If the selected CSI-RS is Zero Power, the Sync Source is forced to Auto.

Source ID - Selects the synchronization source ID when Sync Source is set to SSB, PDSCH DMRS, PDCCH DMRS or CSI-RS.

Sync Mode - sets the synchronization technique. The analyzer attempts to align the measured signal with the location specified by Analysis Start Boundary. This setting modifies the search algorithm used by the analyzer.

If Acquisition Mode is set to Frame trigger is present , Time Cross Correlation is always used internally and the Sync Mode selection does not apply.

CP 1) Contention period, or 2) Cyclic prefix Autocorrelation - (default) If CP Autocorrelation is selected, a frequency domain synchronization strategy using cyclic-prefix correlation is used. This approach typically results in a faster measurement.

Time Cross Correlation - If Time Cross Correlation is selected, a time domain cross correlation synchronization strategy is used. This approach typically results in higher probability of synchronization for noisy signal conditions.

Ignore MIB Data - Only applies when the sync source is SSB. When selected (enabled), this setting may fix synchronization problems due to invalid MIB data present in SS/PBCH indexes of an analyzed signal. This specifically helps cases where SSBlock Lmax is L8 or L64 and Periodicity is half-frame (5 ms). Disabling this setting ensures that certain synchronization scenarios have robust frame offset detection (if SSB contains valid MIB data).

Default: Disabled

Summary

SS/PBCH - Displays the On-Off status of the SS/PBCH.

PDCCH - Displays the On-Off status of each configured PDCCH.

PDSCH - Displays the On-Off status of each configured PDSCH.

CSI-RS - Displays the On-Off status of each configured CSI-RS.

Uplink

Auto Detection - Performs Power-based auto detection for the PUSCH physical channel.

PUSCH - Enables or disables PUSCH auto-detection.

PUSCH auto-detection is a BETA feature for the software.

The PUSCH auto-detection feature attempts to evaluate statistical conditions of the analyzed time waveform to deduce the per-slot/per-RB presence of PUSCH transmissions. This approach works for many PUSCH allocation types. Specifically, single allocation PUSCH transmissions with high SNR are good candidates for this technique.

Certain scenarios listed below are not compatible with this technique:

Measurements with >1 input channel
Signal to noise levels below 25 dB (for QPSK data)
Presence of PUCCH signals. PUCCH selection needs to be disabled whenever PUSCH auto-detection is enabled.
Presence of PTRS (frequently used in FR2 configurations). If present, the measurement will return high PUSCH EVM.
Waveforms with Transform Precoding. Demodulation will not occur when Transform Precoding is enabled.

You must enter all parameters in the Carrier panel and BWP panel correctly before Auto Detection can work. See Understanding 5G NR Auto Detection for more information.

Default: Disabled

PRACH Physical Random Access Channel - Enables or disables PRACH auto-detection.

PRACH Auto Detection does a power based search to detect active the portion from the time-domain waveform, then applies a cross-correlation method to detect each parameter.

The following parameters can be auto-detected.

Preamble Index (Logical Root Sequence Index and Cyclic Shift)
Based on TS38.211, 6.3.3.1, the Auto Detection algorithm searches 64 preamble patterns, generated by a logical root sequence index & a cyclic shift and picks the best one to match. Logical root sequence index to search starts from the PRACH Root Sequence Index parameter, and candidate cyclic shift values are calculated according to the standard’s formula.
Frequency domain parameter (n_RA 1) Random Access, or 2) Receiver Address_f or nRA) of PRACH Occasion Index
PRACH preamble can be mapped at one of M frequency domain locations by specifying n_RA_f, as described by the standard. M is defined by the Msg1 FMD parameter. The Auto Detection algorithm checks M frequency domain locations and picks the best one to match.
Time domain parameters (subframe index, n_RA_t, n_RA_slot) of PRACH Occasion Index, with the following limitation:
Without knowing an absolute time reference, the Auto Detection algorithm cannot detect absolute time location. Thus, once the PRACH burst is detected from the time-domain waveform, the Auto Detection algorithm assumes that it is located at the first time occasion of possible time occasions, such as the first subframe index defined in the TS38 211, Table 6.3.3.2-2, 6.3.3.2-3 & 6.3.3.2-4, n_RA_t = 0, and n_RA_slot = 0. If there are multiple PRACH bursts in the time domain waveform, the Auto Detection algorithm can detect time differences between the first burst and others, then detect the active PRACH burst if a time difference matches with possible time occasions with reference to the first time occasion.

	PRACH auto-detection expects the first occasion index to be 0 (n_RA_t = 0 and n_RA_slot = 0).
	Demodulation may fail in PRACH auto detection mode when multiple occasions are mapped close together in time domain without a gap between them.
	You must enter the following parameters in the PRACH panel before auto detection can work: BWP ID, Spectrum Type, all settings under General/Sequence and all settings under Time/Frequency Allocation.
	You must enter all parameters in the Carrier panel and BWP panel correctly before Auto Detection can work. See Understanding 5G NR Auto Detection for more information.

Synchronization Config

Sync Source - Selects the frame synchronization source. The drop-down list will only display valid (enabled) sources.

Auto - The VSA software tries to select the best synchronization source for the measurement.

Not Provided - (automatically selected when ULPI Features is ON and Valid DMRS Sequence is unchecked) This is a special setting for ORAN ULPI DMRS-BF-EQ beamforming mode, where channel estimation and equalization are performed in the O-RU (DUT Device under Test: An acronym used to describe some type of electrical apparatus connected to test instrumentation. The apparatus can range from a single component to a complex subsystem such as a mobile phone, base station or MSC.). When Not Provided is selected, the VSA skips all synchronization, tracking and equalization, and just performs FFT Fast Fourier Transform: A mathematical operation performed on a time-domain signal to yield the individual spectral components that constitute the signal. See Spectrum., Demodulation and Decoding. Since there is no synchronization source, the IQ data must be aligned with the Frame boundary and Periodic trigger must be used.

PUSCH DMRS - Uses the PUSCH DMRS specified by Source ID as the synchronization source.

PUCCH DMRS - Uses the PUCCH DMRS specified by Source ID as the synchronization source.

SRS - Uses the SRS specified by Source ID as the synchronization source.

PRACH - Uses the PRACH specified by Source ID as the synchronization source.

Source ID - Selects the synchronization source ID when Sync Source is set to PUSCH DMRS, PUCCH DMRS or SRS.

If Acquisition Mode is set to Frame trigger is present , Time Cross Correlation is always used internally and the Sync Mode selection does not apply.

CP Autocorrelation - (default) If CP Autocorrelation is selected, a frequency domain synchronization strategy using cyclic-prefix correlation is used. This approach typically results in a faster measurement.

Time Cross Correlation - If Time Cross Correlation is selected, a time domain cross correlation synchronization strategy is used. This approach typically results in higher probability of synchronization for noisy signal conditions.

Summary

PUSCH - Displays the On-Off status of each configured PUSCH.

PUCCH - Displays the On-Off status of the PUCCH.

PRACH - Displays the On-Off status of each configured PRACH.