This section contains information about applying fixed reference channels (FRC) for both uplink and downlink channels.

You can configure the FRC for both uplink and downlink channels by clicking Apply FRC. For uplink, Apply FRC is enabled for all configurations. For downlink, Apply FRC is enabled only when you set the Channel Configuration Mode to User Defined.

To enable Apply FRC, you must be on the Carrier Definition tab as shown in the following image. FRCs are specific to individual carriers, hence, they are applied only to the selected carrier definition. If Carrier Allocated checkbox is unchecked, Apply FRC is disabled for that carrier definition. FRCs are available according to the selected frequency range.

Configuring FRC

Follow the following steps to configure FRCs for selected carrier definitions:

  1. Click Apply FRC, it opens a new FRC configurations window.
  2. Configure the required parameters for FRCs.
  3. Click Ok to apply changes.
    Note Applying FRC changes overwrite the carrier definition and remove any non-applicable user configurations from the carrier definition setup tree.

FRC Configuration Windows

Depending on the link direction, one of the following windows will appear when you click on Apply FRC.

 Downlink FRC Configuration

This window enables the user to configure downlink FRCs (for UE receiver tests) according to Annex A.3 of 3GPP TS 38.521-1 and 3GPP TS 38.521-2 specifications.

Channel Bandwidth: Specifies the overall bandwidth, comprised of bandwidth parts. Valid values are from 5 MHz to 400 MHz.

FRC Type: Specifies the downlink fixed reference channel table from the specifications.

Subcarrier Spacing: Specifies the supported values based on the selected channel bandwidth.

Duplex Scheme: Specifies the duplex scheme used by the downlink FRCs.

 FDD  Downlink FRCs are configured for FDD operation according to Annex A.3.2 of 3GPP TS 38.521-1 and 3GPP TS 38.521-2 specifications.
 TDD  Downlink FRCs are configured for TDD operation according to Annex A.3.3 of 3GPP TS 38.521-1 and 3GPP TS 38.521-2 specifications.

Uplink FRC Configuration

This window enables the user to configure uplink FRCs (for base station receiver tests) according to Annex A of 3GPP TS 38.141-1 and 3GPP TS 38.141-2 specifications.

Channel Bandwidth: Specifies the overall bandwidth, comprised of bandwidth parts. Valid values are from 5 MHz to 400 MHz.

Duplex Scheme: Specifies the duplex scheme used by the uplink FRCs.

FRC Type: Specifies the uplink fixed reference channel table from the specifications.

DMRS Additional Positions: Specifies the positions of additional DMRS symbols.

 Frequency Range  FRC Types  DMRS Additional Positions
 Frequency Range 1   A.3, A.4, and A.7  1 and 2
A.3B 0 and 1
A.1, A.2, A.3A, A.5, A.8, A.9 and A.12 1
 Frequency Range 2   A.3, A.3A, A.4, A.5, A.7, and A.10  0 and 1
A1, A.3B, NTN A.5 and NTN A.6 1

Transform Precoding: Specifies whether to enable transform precoding. If this parameter is disabled, the signal will be CP-OFDM modulated; otherwise, the signal will be DFT-S-OFDM modulated.

 Frequency Range  FRC Types  Transform Precoding
 Frequency Range 1   A.3  Supported
Others Not supported
 Frequency Range 2   A.3  Supported
 Others Not supported

Number of Tx Antennas: Specifies the number of transmit antennas. This is a read-only parameter, updated from Number of Tx Antennas in Signal Configuration. Other values of Number of Tx Antennas are not supported for FRC configuration.

 Frequency Range  FRC Types  Tx Antennas
 Frequency Range 1   A.3, A.4, A.9, and A.12 1, 2, and 4
 Others 1
 Frequency Range 2  A.3, A.4, and A.7  1 and 2
  Others 1

Reference Channel: Specifies the reference channel for the selected FRC table. The list of supported reference channels depends upon Channel Bandwidth, FRC Type, DMRS Additional Positions, Transform Precoding, and Number of Tx Antennas, and updated based on the selected settings. If the selected settings do not apply to any reference channel, the list will be empty, and an error is shown.

PUSCH Mapping Type: Allows you to choose between Type A and Type B mapping.

 Frequency Range  FRC Types  PUSCH Mapping Type
 Frequency Range 1  A.3, A.3A, A.3B, NTN A.3, A.4, A.5, A.7, A.8, A.9, and A.12  Type A and Type B
  A.1 and A.2   Type A
 Frequency Range 2   A.1  Type A
 A.3, A.3A, A.3B, A.4, A.5, NTN A.5, NTN A.6, A.7, and A.10   Type B

RB Offset: Specifies the resource block offset from where the resource block allocation for PUSCH should start.

FRC tables for UL FR1 conducted (specified in 3GPP 38.141-1 specification) and UL FR1 OTA (specified in 3GPP 38.141-2 specification) are the same. Hence, they are implemented only once for FR1.

PTRS Enabled: Specifies whether to enable adding a PTRS to the waveform.

 Frequency Range  FRC Types  PTRS Enabled
 Frequency Range 1  All  Not supported
 Frequency Range 2   A.1, A.3, A.3A, A.3B, NTN A.5, and NTN A.6  Not supported
 A.4, A.5, A.7, and A.10  Supported
Note TBoMS in not supported in FRC type A.3

Interlace Index: Specifies the interlace index for interlaced RB allocation in NR-U cases.