# nrWavegenSRSConfig

SRS configuration parameters for 5G waveform generation

Since R2021a

## Description

The nrWavegenSRSConfig object sets sounding reference signal (SRS) configuration parameters, as defined in TS 38.211 Section 6.4.1.4 [1]. Use this object to set the SRS property of the nrULCarrierConfig object when configuring 5G uplink waveform generation.

The default nrWavegenSRSConfig object specifies a single-port, single-symbol, narrowband SRS configuration without frequency hopping (BHopBSRS) and places the SRS at the end of the slot.

## Creation

### Description

srs = nrWavegenSRSConfig creates a default SRS configuration object for 5G waveform generation.

example

srs = nrWavegenSRSConfig(Name,Value) specifies properties using one or more name-value arguments. Enclose each property in quotes. For example, 'NumSRSPorts',2,'NumSRSSymbols',4 specifies a two-port SRS transmission of 4 OFDM symbols.

## Properties

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Enable the SRS in 5G waveform generation, specified as one of these values.

• 1 (true) — Enable the SRS.

• 0 (false) — Disable the SRS.

Data Types: double | logical

Name of the SRS configuration, specified as a character array or string scalar. Use this property to set a description to the SRS configuration.

Data Types: char | string

Power scaling of the SRS in dB, specified as a real scalar. Use this property to scale the power of the SRS in the generated 5G waveform.

Data Types: double

ID of the bandwidth part (BWP) containing the configured SRS, specified as a nonnegative integer. Use this property to associate this SRS configuration with one of the BWP configurations specified by the BandwidthParts property of the nrULCarrierConfig object.

Data Types: double

Number of SRS antenna ports, specified as 1, 2, or 4.

Data Types: double

0-based index of the first OFDM symbol in the SRS within a slot, specified as one of these options:

• Integer from 0 to 13 — Use this option for normal cyclic prefix.

• Integer from 0 to 11 — Use this option for extended cyclic prefix.

For the SRS symbols and index generation, set the cyclic prefix of the carrier by using the CyclicPrefix property of the BWP configuration object specified by the BandwidthPartID property.

Data Types: double

Number of OFDM symbols allocated to the SRS in slot, specified as 1, 2, 4, 8, 10, 12, or 14. Property values 10 and 14 are only valid when you set the SRSPositioning property to 0 (false).

When you set the SRSPositioning property to 1 (true), for valid configurations of this property and the KTC property, see TS 38.211 Table 6.4.1.4.3-2. Alternatively, to display this table, type nrSRSConfig.SubcarrierOffsetTable at the command line.

Data Types: double

Slot allocation in an SRS period, specified as a nonnegative integer or a row vector of nonnegative integers. This property specifies the slot positions of the SRS by using 0-based indexing and values that are less than the value of the Period property. The object ignores slot allocation values that are greater than the period. Each element of the vector corresponds to an SRS resource.

Data Types: char

SRS allocation period in slots, specified as a nonnegative integer or []. An empty period indicates aperiodic SRS resource type (no repetition), as defined in TS 38.211 Section 6.4.1.4.3.

Data Types: double

Frequency-domain offset of the SRS, in terms of a physical resource block (PRB) index relative to the carrier, specified as an integer from 0 to 271. FrequencyStart is analogous to parameter ${n}_{{}_{shift}}$ from TS 38.211 Section 6.4.1.4.3.

This property, the additional circular frequency-domain offset property NRRC, and the bandwidth configuration parameters in TS 38.211 Table 6.4.1.4.3-1 determine the actual frequency-domain location of the SRS. For more information, see NR SRS Configuration.

Data Types: double

Additional circular frequency-domain offset of the SRS, as a multiple of 4 PRBs, specified as an integer from 0 to 67.

This property, the frequency domain offset property FrequencyStart, and the bandwidth configuration parameters in TS 38.211 Table 6.4.1.4.3-1 determine the actual frequency-domain location of the SRS. For more information, see NR SRS Configuration.

Data Types: double

Row index of the bandwidth configuration table from TS 38.211 Table 6.4.1.4.3-1, specified as an integer from 0 to 63. Use this property with the BSRS property to control the bandwidth allocated to the SRS and the frequency hopping pattern. Increasing the CSRS value increases the SRS bandwidth. The default value of 0 results in a bandwidth of 4 PRBs.

Data Types: double

Column index of the bandwidth configuration table from TS 38.211 Table 6.4.1.4.3-1, specified as an integer from 0 to 3. Use this property with the CSRS property to control the bandwidth allocated to the SRS and the frequency hopping pattern. Increasing the BSRS value decreases the SRS bandwidth.

Data Types: double

Frequency hopping index, specified as an integer from 0 to 3. Setting this property to a value greater than or equal to the column index of the bandwidth configuration table property, BSRS, disables frequency hopping. Increasing the BHop value decreases the hopping bandwidth.

Data Types: double

Repetition factor of OFDM symbols, specified as 1, 2, 4, 5, 6, 7, 8, 10, 12, or 14.

• When frequency hopping is enabled, Repetition specifies the number of consecutive OFDM symbols in a slot occupied by the SRS in the same frequency resource. Set Repetition such that RepetitionNumSRSSymbols.

• When frequency hopping is disabled, this property is ignored.

Data Types: double

Transmission comb number, in subcarriers, specified as 2, 4, or 8. This property specifies the minimum frequency separation between two subcarriers that allocate SRS.

When you set the SRSPositioning property to 1 (true), for valid configurations of this property and the NumSRSSymbols property, see TS 38.211 Table 6.4.1.4.3-2. Alternatively, to display this table, type nrSRSConfig.SubcarrierOffsetTable at the command line.

Data Types: double

Transmission comb offset, in subcarriers, specified as an integer from 0 to (KTC – 1). This property specifies a frequency offset within the comb.

Data Types: double

Frequency scaling factor, specified as 1, 2, or 4. Use this property to reduce the SRS transmission bandwidth for partial frequency sounding. This property corresponds to the parameter PF in Release 17 of TS 38.211 Section 6.4.1.4.3. The default value 1 disables frequency scaling.

Data Types: double

Partial frequency sounding block index, specified as a nonnegative integer in the range [0, FrequencyScalingFactor–1].

Use this property to control the SRS frequency position when you set the FrequencyScalingFactor property to 2 or 4.

Data Types: double

Enable frequency hopping of the first RB in the SRS transmission for partial frequency sounding, specified as one of these logical values.

• 0 (false) — Disable frequency hopping of the first RB.

• 1 (true) — Enable frequency hopping of the first RB.

Use this property to control the frequency hopping of the first RB when you set the FrequencyScalingFactor property to 2 or 4.

Data Types: logical | double

Cyclic shift offset, specified as an integer from 0 to 11. This property determines the cyclic shift applied to the SRS sequence for each antenna port. This property corresponds to parameter ${n}_{SRS}^{cs}$ in TS 38.211 Section 6.4.1.4.2.

Set the cyclic shift offset in relation to the transmission comb property, KTC:

• If you set KTC to 2, set CyclicShift to an integer from 0 to 7.

• If you set KTC to 4, set CyclicShift to an integer from 0 to 11.

• If you set KTC to 8, set CyclicShift to an integer from 0 to 5.

For multiport SRS transmissions, consecutive cyclic shift numbers are used for each port, modulo 6, 8, or 12, depending on the KTC property.

Data Types: double

Type of SRS symbol hopping, specified as 'neither', 'groupHopping', or 'sequenceHopping'. When either group or sequence hopping is enabled, the group or sequence hopping numbers per OFDM symbol in the SRS transmission are based on a pseudo-random binary sequence (PRBS). Set the scrambling identity for the PRBS by using the NSRSID property.

Data Types: char | string

SRS scrambling identity, specified as an integer from 0 to 65,535.

• When you set the GroupSeqHopping property to 'neither', this property determines the group number.

• When you set the GroupSeqHopping property to 'groupHopping' or 'sequenceHopping', this property initializes the PRBS.

Data Types: double

SRS for user positioning, as defined in Release 16 of TS 38.211 Section 6.4.1.4, specified as one of these values.

• 0 (false) — Disable SRS for user positioning. This option corresponds to the higher-layer parameter SRS-Resource.

• 1 (true) — Enable SRS for user positioning. This option corresponds to the higher-layer parameter SRS-PosResource-r16.

This property affects the valid range of the NumSRSSymbols and KTC properties.

Data Types: logical | double

## Examples

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Create two SCS carrier configuration objects with mixed numerologies and custom numbers of resource blocks.

carriers = {
nrSCSCarrierConfig('SubcarrierSpacing',15,'NStartGrid',10,'NSizeGrid',100), ...
nrSCSCarrierConfig('SubcarrierSpacing',30,'NStartGrid',0,'NSizeGrid',70)};

Create two BWP configuration objects, one for each of the SCS carriers.

bwp = {
nrWavegenBWPConfig('BandwidthPartID',1,'SubcarrierSpacing',15,'NStartBWP',10,'NSizeBWP',80), ...
nrWavegenBWPConfig('BandwidthPartID',2,'SubcarrierSpacing',30,'NStartBWP',0,'NSizeBWP',60)};

Create two SRS configuration objects, one for each of the carriers, with the specified properties. In the first SRS configuration, frequency hopping is enabled. In the second SRS configuration, frequency hopping is disabled.

srs = {
nrWavegenSRSConfig('BandwidthPartID',2,'FrequencyStart',4)};

Create a PUSCH configuration object such that the PUSCH does not overlap with the previously configured SRS in the generated waveform.

pusch = {
nrWavegenPUSCHConfig('BandwidthPartID',1,'SymbolAllocation',[0 8],'PRBSet',(10:51))};

Create an uplink carrier configuration object, specifying the previously defined configurations.

cfg = nrULCarrierConfig( ...
'SCSCarriers',carriers, ...
'BandwidthParts',bwp, ...
'SRS',srs, ...
'PUSCH',pusch);

## References

[1] 3GPP TS 38.211. “NR; Physical channels and modulation.” 3rd Generation Partnership Project; Technical Specification Group Radio Access Network.

## Version History

Introduced in R2021a

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