8.2 UE sounding procedure

36.2133GPPEvolved Universal Terrestrial Radio Access (E-UTRA)Physical layer proceduresRelease 17TS

If the UE is configured with a PUCCH-SCell, the UE shall apply the procedures described in this clause for both primary PUCCH group and secondary PUCCH group unless stated otherwise

  • When the procedures are applied for the primary PUCCH group, the terms ‘secondary cell’, ‘secondary cells’, ‘serving cell’, and ‘serving cells’ in this clause refer to secondary cell, secondary cells, serving cell or serving cells belonging to the primary PUCCH group respectively unless stated otherwise.
  • When the procedures are applied for secondary PUCCH group, the terms ‘secondary cell’, ‘secondary cells’, ‘serving cell’ and ‘serving cells’ in this clause refer to secondary cell, secondary cells (not including the PUCCH-SCell), serving cell, serving cells belonging to the secondary PUCCH group respectively unless stated otherwise. The term ‘primary cell’ in this clause refers to the PUCCH-SCell of the secondary PUCCH group.

A UE shall transmit Sounding Reference Symbol (SRS) on per serving cell SRS resources based on three trigger types:

– trigger type 0: higher layer signalling

– trigger type 1: DCI formats 0/0A/0B/4/4A/4B/1A/6-0A/6-1A for FDD, TDD, and frame structure type 3 and DCI formats 2B/2C/2D/3B for TDD, and frame structure type 3, and DCI format 7-0A/7-0B/7-1E/7-1F/7-1G for TDD if the UE is configured by higher layers for SRS triggering via DCI format 7-0A and has indicated the capability srs-DCI7-Triggering-FS2-r15/ srs-DCI7-Triggering-FS2-r16 and the UE is configured for SRS triggering with srs-DCI7-TriggeringConfig-r15/ srs-DCI7-Triggering-FS2-r16.

  • trigger type 2: DCI formats 0/4/1A for FDD and TDD, and DCI formats 2B/2C/2D/3B for TDD, and DCI format 7-0A/7-0B/7-1E/7-1F/7-1G for TDD if the UE is configured by higher layers for SRS triggering via DCI format 7-0A and has indicated the capability srs-DCI7-Triggering-FS2-r16 and the UE is configured for SRS triggering with srs-DCI7-TriggeringConfig-r16.

A UE is not expected to be configured with SRS trigger type 0 and trigger type 2 on a LAA SCell.

In case both trigger type 0 and trigger type 1 SRS transmissions would occur in the same subframe in the same serving cell, the UE shall only transmit the trigger type 1 SRS transmission. This prioritization rule shall be applied before other prioritization rules defined in this clause.

In case both trigger type 1 and trigger type 2 SRS transmissions would occur in the same subframe, the UE shall transmit both the trigger type1 and type 2 SRS transmissions.

In case both trigger type 0 and trigger type 2 SRS transmissions would occur in the same subframe, the UE shall transmit both the trigger type 0 and type 2 SRS transmissions.

If higher layer parameter specialSubframePatterns-v1430 indicates ssp10, or if higher layer parameter specialSubframePatterns-v1450 indicates ssp10-CRS-LessDwPTS, the UE shall assume for the purpose of determining that the special subframe configuration is that signalled by specialSubframePatterns (without suffix).

A UE may be configured with SRS parameters for trigger type 0 and trigger type 1/2 on each serving cell. A BL/CE UE configured with CEModeB is not expected to be configured with SRS parameters for trigger type 0 and trigger type 1. A BL/CE UE is not expected to be configured with SRS parameters for trigger type 2.The following SRS parameters are serving cell specific and semi-statically configurable by higher layers for trigger type 0 and for trigger type 1/2.

– Number of combs as defined in Clause 5.5.3.2 of [3] for trigger type 0 and each configuration of trigger type 1/2, if configured

– srs-UpPtsAdd: two or four additional SC-FDMA symbols in UpPTS as defined in [11] for trigger type 0 and trigger type 1, if configured

– Transmission comb , as defined in Clause 5.5.3.2 of [3] for trigger type 0 and each configuration of trigger type 1/2

– Starting physical resource block assignment , as defined in Clause 5.5.3.2 of [3] for trigger type 0 and each configuration of trigger type 1/2 for a serving cell that is not a LAA SCell. For a serving cell that is a LAA SCell, .

– duration: single or indefinite (until disabled), as defined in [11] for trigger type 0

– srs-ConfigIndex ISRS for SRS periodicity and SRS subframe offset , as defined in Table 8.2-1 and Table 8.2-2 for trigger type 0 and SRS periodicity and SRS subframe offset , as defined in Table 8.2-4 for trigger type 1 and Table 8.2-5 trigger for type 1/2 for a serving cell that is not a LAA SCell

– SRS bandwidth , as defined in Clause 5.5.3.2 of [3] for trigger type 0 and each configuration of trigger type 1/2 for a serving cell that is not a LAA SCell. For a serving cell that is a LAA SCell, .

– Frequency hopping bandwidth, , as defined in Clause 5.5.3.2 of [3] for trigger type 0 and each configuration of type 2

– Cyclic shift , as defined in Clause 5.5.3.1 of [3] for trigger type 0 and each configuration of trigger type 1/2

– Number of antenna ports for trigger type 0 and each configuration of trigger type 1/2

– SRS subframe for each configuration of trigger type 1 for a serving cell that is a LAA SCell and DCI format 4B

  • Starting SC-FDMA symbol and duration and repetition number as defined in Clause 5.5.3.2.2 of [3] for each configuration of SRS trigger type 2.

For a TDD serving cell,

– If the serving cell not configured for PUSCH/PUCCH transmission, or if the UE supports ce-srsEnhancement-r14

– For trigger type 0, the UE can be configured with more than one configuration of SoundingRS-UL-ConfigDedicatedUpPTsExt and/or SoundingRS-UL-ConfigDedicated, and the SRS parameters in each of the configurations shall be used. The UE is not expected to receive more than one SRS configuration indicating SRS transmission on multiple symbols in different subframes within a half frame.

– For trigger type 1, the UE can be configured with more than one configuration of SoundingRS-UL- ConfigDedicatedAperiodicUpPTsExt and/or SoundingRS-UL- ConfigDedicatedAperiodic, and the SRS parameters in each of the configurations shall be used. The UE is not expected to receive more than one SRS configuration indicating SRS transmission on multiple symbols in different subframes within a half frame.

– For trigger type 2, the parameters in SoundingRS-UL-ConfigDedicatedAdd shall be used.

– Otherwise

– For trigger type 0, if SoundingRS-UL-ConfigDedicatedUpPTsExt is configured, the SRS parameters in SoundingRS-UL-ConfigDedicatedUpPTsExt shall be used; otherwise, SoundingRS-UL-ConfigDedicated shall be used.

– For trigger type 1, if SoundingRS-UL-ConfigDedicatedAperiodicUpPTsExt is configured, the SRS parameters in SoundingRS-UL-ConfigDedicatedAperiodicUpPTsExt shall be used; otherwise, SoundingRS-UL-ConfigDedicatedAperiodic shall be used.

– For trigger type 2, the parameters in SoundingRS-UL-ConfigDedicatedAdd shall be used.

For trigger type 1 and DCI format 4/4A/4B/7-0B, and trigger type 2 and DCI format 4/7-0B, three sets of SRS parameters, srs-ConfigApDCI-Format4, are configured by higher layer signalling. The 2-bit SRS request field [4] in DCI format 4/4A/4B/7-0B indicates the SRS parameter set given in Table 8.1-1. For trigger type 1 and DCI format 0/0A/0B /6-0A/7-0A, and trigger type 2 and DCI format 0/6-0A/7-0A, a single set of SRS parameters, srs-ConfigApDCI-Format0, is configured by higher layer signalling. For trigger type 1/2 and DCI formats 1A/2B/2C/2D/6-1A/7-1E/7-1F/7-1G, a single common set of SRS parameters, srs-ConfigApDCI-Format1a2b2c, is configured by higher layer signalling. For a serving cell that is not a LAA SCell, the SRS request field is 1 bit [4] for DCI formats 0/1A/2B/2C/2D/6-0A/6-1A/7-0A/7-1E/7-1F/7-1G, with type 1/2 SRS triggered if the value of the SRS request field is set to ‘1’. For a serving cell that is a LAA SCell, the SRS timing offset field is 3 bits [4] for DCI formats 1A/2B/2C/2D, with a type 1 SRS triggered if the value of the SRS timing offset field is not set to ‘000’. The SRS request field is 1 bit [4] for DCI formats 0A, with type 1/2 SRS triggered if the value of the SRS request field is set to ‘1’. The 2-bit SRS request field [4] in DCI format 0B indicates the type 1 SRS triggering and PUSCH subframe (as determined in Clause 8.0) with SRS as given in Table 8.2-0A.

For a serving cell that is not a LAA SCell, a 1-bit SRS request field shall be included in DCI formats 0/1A for frame structure type 1 and 0/1A/2B/2C/2D for frame structure type 2 if the UE is configured with SRS parameters for DCI formats 0/1A/2B/2C/2D by higher-layer signalling. A 1-bit SRS request field shall be included in DCI format 7-0A for frame structure type 2 if the UE is configured with SRS parameters srs-ConfigApDCI-Format0 and srs-DCI7-TriggeringConfig-r15 by higher-layer signalling. A 1-bit SRS request field shall be included in DCI formats 7-1E/7-1F/7-1G for frame structure type 2 if the UE is configured with SRS parameters srs-ConfigApDCI-Format1a2b2c and srs-DCI7-TriggeringConfig-r15 by higher-layer signalling. A 1-bit SRS request field shall be included in DCI formats 6-0A/6-1A, the value of which is reserved if the UE is not configured with SRS parameters for DCI formats 6-0A/6-1A by higher layer signalling.

For a TDD serving cell not configured for PUSCH/PUCCH transmission, and trigger type 1/2, a SRS request field [4] shall be included in DCI format 3B if the value of the higher layer parameter fieldTypeFormat3B is set to 3 or 4. If the UE is configured with more than 5 TDD serving cells without PUSCH/PUCCH transmission, a single SRS request field is included in DCI format 3B for a set of the TDD serving cells without PUSCH/PUCCH transmission as given in Table 8.2-0C; otherwise one or more SRS request fields is included in DCI format 3B each corresponding to a TDD serving cell without PUSCH/PUCCH transmission as configured by higher layers. If the UE is configured with no more than 5 TDD serving cells without PUSCH/PUCCH transmission, and the UE is not configured with srs-ConfigApDCI-Format4, the SRS request field [4] in DCI format 3B is 1-bit, 2-bits otherwise. For the 1-bit SRS request field [4] in DCI format 3B, type 1/2 SRS is triggered if the value of the SRS request field is set to ‘1’ with SRS parameters, srs-ConfigApDCI-Format1a2b2c, configured by higher layer signalling. For the 2-bit SRS request field [4] in DCI format 3B, and UE configured with no more than 5 TDD serving cells without PUSCH/PUCCH transmission, the SRS request field indicates the SRS parameter set given in Table 8.1-1 with the three sets of SRS parameters, srs-ConfigApDCI-Format4, configured by higher layer signalling. For the 2-bit SRS request field [4] in Table 8.2-0C and DCI format 3B, and UE configured with more than 5 TDD serving cells without PUSCH/PUCCH transmission, SRS parameters, srs-ConfigApDCI-Format1a2b2c, configured by higher layer signalling for the associated serving cell, is used if type 1/2 SRS is triggered. For the 2-bit SRS request field [4] in Table 8.2-0C and DCI format 3B, and UE configured with more than 5 TDD serving cells without PUSCH/PUCCH transmission, if the UE receives an SRS request field with value ’00’, the DCI does not indicate type 1/2 SRS trigger, but the UE shall apply the power control commands received in the DCI format 3B according to Clause 5.1.3.1.

Table 8.1-1: SRS request value for trigger type 1/2 in DCI format 4/7-0B, or trigger type 1 in DCI format 4A/4B

Value of SRS request field

Description

’00’

No type 1/2 SRS trigger

’01’

The 1st SRS parameter set configured by higher layers

’10’

The 2nd SRS parameter set configured by higher layers

’11’

The 3rd SRS parameter set configured by higher layers

Table 8.2-0A: SRS request value for trigger type 1 in DCI format 0B

Value of SRS request field

Description

’00’

No type 1 SRS trigger

’01’

Type 1 SRS trigger and first scheduled PUSCH subframe

’10’

Type 1 SRS trigger and second scheduled PUSCH subframe

’11’

Type 1 SRS trigger and last scheduled PUSCH subframe

Table 8.2-0C: SRS request value for trigger type 1/2 in DCI format 3B and for UE configured with more than 5 TDD serving cells without PUSCH/PUCCH transmission

Value of SRS request field

Description

’00’

No type 1/2 SRS trigger for a 1st set of serving cells configured by higher layers

’01’

Type 1/2 SRS trigger for a 2nd set of serving cells configured by higher layers

’10’

Type 1/2 SRS trigger for a 3rd set of serving cells configured by higher layers

’11’

Type 1/2 SRS trigger for a 4th set of serving cells configured by higher layers

For all DCI formats with type 1/2 SRS trigger, each SRS parameter set contains one trigger type 1 and/or one trigger type 2 SRS configuration. When a SRS parameter set is triggered with the 1-bit SRS request set to 1 (for DCI formats with 1-bit SRS request field) or with the corresponding SRS request field value signalled (for DCI formats with 2-bits SRS request field), the configured trigger type 1 and/or trigger type 2 SRS is transmitted according to their respective configurations.

For a serving cell that is not a LAA SCell, the serving cell specific SRS transmission bandwidths are configured by higher layers. The allowable values are given in Clause 5.5.3.2 of [3].

For a serving cell that is not a LAA SCell, the serving cell specific SRS transmission sub-frames are configured by higher layers. The allowable values are given in Clause 5.5.3.3 of [3].

For a TDD serving cell, trigger type 0 and 1 SRS transmissions can occur in UpPTS and uplink subframes of the UL/DL configuration indicated by the higher layer parameter subframeAssignment for the serving cell. Trigger type 2 SRS transmissions can occur in uplink subframes of the UL/DL configuration indicated by the higher layer parameter subframeAssignment for the serving cell except the last symbol of a subframe.

For trigger type 0 and type 1 SRS transmission, when closed-loop or open-loop UE transmit antenna selection is enabled for a given serving cell for a UE that supports transmit antenna selection, or for a UE that can be configured with ue-TxAntennaSelection-SRS-1T4R-Config or ue-TxAntennaSelection-SRS-2T4R-NrOfPairs,

  • when higher layer parameter ‘ue-TxAntennaSelection-SRS-1T4R-Config‘ is configured for a given serving cell, the index , of the UE antenna that transmits the SRS at time nSRS is given by

, for both partial and full sounding bandwidth, and when frequency hopping is disabled (i.e., ),

with, when frequency hopping is enabled (i.e., ).

  • when higher layer parameter ‘ue-TxAntennaSelection-SRS-2T4R-NrOfPairs‘ is configured for a given serving cell for a UE configured with UE antenna pairs, where is given by higher layer parameter ‘ue-TxAntennaSelection-SRS-2T4R-NrOfPairs’, the index for the UE antenna pair as when =2, or when =3 that transmits the SRS at time nSRS is given by

for both partial and full sounding bandwidth, and when frequency hopping is disabled (i.e., ),

with , when frequency hopping is enabled (i.e., ).

– otherwise, the index , of the UE antenna that transmits the SRS at time nSRS is given by

, for both partial and full sounding bandwidth, and when frequency hopping is disabled (i.e., ),

,

when frequency hopping is enabled (i.e., ),

where values BSRS, bhop, Nb, and nSRS are given in Clause 5.5.3.2 of [3], and (where regardless of the value), except when a single SRS transmission is configured for the UE. If a UE is configured with more than one serving cell, and for a group of cells belonging to bands that are signalled to be switched together in txAntennaSwitchUL the UE is not expected to transmit SRS on different antenna ports simultaneously. If a UE is configured with more than one serving cell, and for a group of cells belonging to bands that are signalled to be switched together in txAntennaSwitchUL the UE is not expected to transmit SRS and PUSCH on different antenna ports simultaneously.

For trigger type 2 SRS transmission, when closed-loop or open-loop UE transmit antenna selection is enabled for a given serving cell for a UE that supports antenna selection, or for UE that can be configured with ue-TxAntennaSelection-SRS-1T4R-Config or ue-TxAntennaSelection-SRS-2T4R-NrOfPairs, the index of the UE antenna that transmits the SRS at time nSRS is given by when frequency hopping is disabled, and when frequency hopping is enabled, where is the number of frequency hops defined in Clause 5.5.3.2.2 of [3]. The UE is not expected to be configured with and

– when higher layer parameter ‘ue-TXAntennaSelection-SRS-1T4R-Config’ is configured for a given serving cell, the number of antenna switches = 4.

– when higher layer parameter ‘ue-TXAntennaSelection-SRS-2T4R-NrOfPairs’ is configured for a given serving cell for a UE configured with UE antenna pairs, where is given by higher layer parameter ‘ue-TXAntennaSelection-SRS-2T4R-NrOfPairs’, the number of antenna switches = , and the index for the UE antenna pair that transmits the SRS at time is when =2, or when =3.

– otherwise, the number of antenna switches = 2.

When higher layer parameter ‘ue-TxAntennaSelection-SRS-1T4R-Config‘ is configured or ‘ue-TxAntennaSelection-SRS-2T4R-NrOfPairs‘ is configured for a serving cell, a UE is not expected to be configured with more than two antenna ports for any uplink physical channel or signal on that serving cell.

A UE may be configured to transmit SRS on antenna ports of a serving cell where may be configured by higher layer signalling. For PUSCH transmission mode 1 and for PUSCH transmission mode 2 with two antenna ports configured for PUSCH and with 4 antenna ports configured for PUSCH. A UE configured for SRS transmission on multiple antenna ports of a serving cell shall transmit SRS for all the configured transmit antenna ports within one SC-FDMA symbol of the same subframe of the serving cell.
The SRS transmission bandwidth and starting physical resource block assignment are the same for all the configured antenna ports of a given serving cell. The UE does not support a value of set to ‘4’, if the UE is configured for SRS transmission on 4 antenna ports of a serving cell.

If a UE is not configured with multiple TAGs and the UE is not configured with the parameter srs-UpPtsAdd for trigger type 1 and the UE is not configured with trigger type 2 SRS transmission, or if a UE is not configured with multiple TAGs and the UE is not configured with more than one serving cell of different CPs and the UE is not configured with trigger type 2 SRS transmission, or if a UE is configured for PUSCH transmission in UpPTS and a SRS transmission overlaps with a PUSCH transmission on the same symbol in UpPTS within a TDD serving cell, the UE shall not transmit trigger type 0/1 SRS in a symbol whenever SRS and PUSCH transmissions happen to overlap in the same symbol, except when the SRS is on a TDD serving cell not configured for PUSCH/PUCCH transmission.

For the case when a trigger type 0/1 SRS transmission in a first serving cell happens to overlap in the same symbol as a PUSCH transmission in a second serving cell, and the first and second serving cells are in the same TAG, same band, and use the same cyclic prefix, the UE may drop the trigger type 0/1 SRS transmission.

For the case when a trigger type 2 SRS transmission in a first serving cell happens to overlap in the same symbol as the PUSCH/PUCCH transmission in a second serving cell, and the first and second serving cells are in the same TAG, same band, and use the same cyclic prefix, the UE may drop the trigger type 2 SRS transmission in the overlapped symbol.

For TDD serving cell, and UE not configured with additional SC-FDMA symbols in UpPTS, when one SC-FDMA symbol exists in UpPTS of the given serving cell, it can be used for SRS transmission, when two SC-FDMA symbols exist in UpPTS of the given serving cell, both can be used for SRS transmission and for trigger type 0 SRS both can be assigned to the same UE. For TDD serving cell, and if the UE is configured with two or four additional SC-FDMA symbols in UpPTS of the given serving cell, all can be used for SRS transmission and for trigger type 0 SRS at most two SC-FDMA symbols out of the configured additional SC-FDMA symbols in UpPTS can be assigned to the same UE, except for UE not configured for PUSCH/PUCCH transmission or for UE supporting ce-srsEnhancement-r14, where all can be assigned to the same UE. A UE is not expected to be configured with trigger type 2 SRS in UpPTS.

If a UE is not configured with multiple TAGs and the UE is not configured with the parameter srs-UpPtsAdd for trigger type 1 and the UE is not configured with trigger type 2 SRS transmission, or if a UE is not configured with multiple TAGs and the UE is not configured with more than one serving cell of different CPs and the UE is not configured with trigger type 2 SRS transmission, or if a UE is configured with multiple TAGs and trigger type 0/1 SRS and PUCCH format 2/2a/2b happen to coincide in the same subframe in the same serving cell, except when the SRS is on a TDD serving cell not configured for PUSCH/PUCCH transmission,

– The UE shall not transmit type 0 triggered SRS whenever type 0 triggered SRS and PUCCH format 2/2a/2b transmissions happen to coincide in the same subframe;

– The UE shall not transmit type 1 triggered SRS whenever type 1 triggered SRS and PUCCH format 2a/2b or format 2 with HARQ-ACK transmissions happen to coincide in the same subframe;

– The UE shall not transmit PUCCH format 2 without HARQ-ACK whenever type 1 triggered SRS and PUCCH format 2 without HARQ-ACK transmissions happen to coincide in the same subframe.

If a UE is not configured with multiple TAGs and the UE is not configured with the parameter srs-UpPtsAdd for trigger type 1 and the UE is not configured with trigger type 2 SRS transmission, or if a UE is not configured with multiple TAGs and the UE is not configured with more than one serving cell of different CPs and the UE is not configured with trigger type 2 SRS transmission, or if a UE is configured with multiple TAGs and trigger type 0/1 SRS and PUCCH happen to coincide in the same subframe/slot/subslot in the same serving cell, except when the SRS is on a TDD serving cell not configured for PUSCH/PUCCH transmission,

– The UE shall not transmit trigger type 0/1 SRS whenever SRS transmission and PUCCH transmission carrying HARQ-ACK and/or positive SR happen to coincide in the same subframe/slot/subslot if the parameter ackNackSRS-SimultaneousTransmission is FALSE;

– For FDD-TDD and primary cell frame structure 1, the UE shall not transmit trigger type 0/1 SRS in a symbol whenever SRS transmission and PUCCH transmission carrying HARQ-ACK and/or positive SR using shortened format as defined in Clauses 5.4.1, 5.4.2A, 5.4.2B, 5.4.2C, and 5.4A of [3] happen to overlap in the same symbol if the parameter ackNackSRS-SimultaneousTransmission is TRUE.

– Unless otherwise prohibited, the UE shall transmit trigger type 0/1 SRS whenever SRS transmission and PUCCH transmission carrying HARQ-ACK and/or positive SR using shortened format as defined in Clauses 5.4.1, 5.4.2A, and 5.4A of [3] happen to coincide in the same subframe/slot/subslot if the parameter ackNackSRS-SimultaneousTransmission is TRUE.

If a UE is not configured with multiple TAGs and the UE is not configured with the parameter srs-UpPtsAdd for trigger type 1 and the UE is not configured with trigger type 2 SRS transmission, or if a UE is not configured with multiple TAGs and the UE is not configured with more than one serving cell of different CPs and the UE is not configured with trigger type 2 SRS transmission, the UE shall not transmit SRS whenever SRS transmission on any serving cells and PUCCH transmission carrying HARQ-ACK and/or positive SR using normal PUCCH format as defined in Clauses 5.4.1, 5.4.2A, and 5.4A of [3] happen to coincide in the same subframe/slot/subslot.

In UpPTS, whenever SRS transmission instance overlaps with the PRACH region for preamble format 4 or exceeds the range of uplink system bandwidth configured in the serving cell, the UE shall not transmit SRS.

For a TDD serving cell d not configured for PUSCH/PUCCH transmission, denote as s0(d) the corresponding serving cell whose UL transmissions may be interrupted as signalled by srs-SwitchFromServCellIndex. Define the set S(d)= {s0(d)… sN-1(d)} as the set of serving cells that meet the all the following conditions:

– {s0(d)… sN-1(d)} are in the same band as s0(d).

– {s0(d)… sN-1(d)} have the same CP as s0(d).

– {s0(d)… sN-1(d)} are in the same TAG as s0(d).

The following prioritization rules shall be applied in case of collision between a transmission of SRS over serving cell d and transmission of a physical signal/channel over a serving cell in set S(d):

– If PUSCH/PUCCH transmission carrying HARQ-ACK/positive SR/RI/PTI/CRI/wideband PMI only (PUCCH reporting type 2a in Clause 7.2.2) and/or PRACH on a serving cell in set S(d) overlaps in the same symbol with the SRS transmission (including any interruption due to uplink or downlink RF retuning time [10]) on serving cell d, then the UE shall not transmit trigger type 0/1 SRS or drop the overlapped symbol(s) of type 2 SRS (including any interruption due to uplink or downlink RF retuning time [10]). Otherwise,

– if PUSCH transmission carrying aperiodic CSI on a serving cell in set S(d) overlaps in the same symbol with the SRS transmission (including any interruption due to uplink or downlink RF retuning time [10]) in serving cell d, and if the SRS transmission is a type 0 SRS transmission, then the UE shall not transmit the type 0 SRS. Otherwise,

– if PUSCH transmission on a serving cell in set S(d) overlaps in more than one symbol with the SRS transmission (including any interruption due to uplink or downlink RF retuning time [10]) in serving cell d, then the UE shall drop the PUSCH transmission. If PUCCH/trigger type 0/1 SRS transmission on a serving cell in set S(d) overlaps in the same symbol with the SRS transmission (including any interruption due to uplink or downlink RF retuning time [10]) on serving cell d, the UE shall drop the PUCCH/trigger type 0/1 SRS transmission. If a subset of symbol(s) for type 2 SRS transmission on a serving cell in set S(d) overlaps with the SRS transmission (including any interruption due to uplink or downlink RF retuning time [10]) on serving cell d, the UE shall drop the subset of the symbol(s) for type 2 SRS on a serving cell in set S(d).

In case an SRS transmission in subframe N on serving cell d is dropped due to a collision with a higher priority transmission (as defined above) in subframe N+1, and there is a lower priority transmission (as defined above) in subframe N that would have been dropped had the transmission in subframe N+1 not occurred, the UE is not required to transmit the lower priority transmission in subframe N.

The UE is not expected to be triggered to transmit type 2 SRS on serving cell d in subframe N that overlaps (including any interruption due to uplink or downlink RF retuning time [10]) with uplink subframe N-1 on a serving cell in set S(d).

The parameter ackNackSRS-SimultaneousTransmission provided by higher layers determines if a UE is configured to support the transmission of HARQ-ACK on PUCCH and SRS in one subframe/slot/subslot. If it is configured to support the transmission of HARQ-ACK on PUCCH and SRS in one subframe/slot/subslot, then in the cell specific SRS subframes of the primary cell in case of subframe-PUCCH or in the last slot/subslot of the cell specific SRS subframes of the primary cell in case of slot/subslot-PUCCH,

– if the UE transmits PUCCH format 1/1a/1b/3, the UE shall transmit HARQ-ACK and SR using the shortened PUCCH format as defined in Clauses 5.4.1, 5.4.2A, and 5.4A.3 of [3], where the HARQ-ACK or the SR symbol corresponding to the SRS location in the last symbol of the subframe is punctured.

– If the UE transmits PUCCH format 4/5 partly or fully overlapping with the cell specific SRS bandwidth in the cell specific SRS subframes of the primary cell, then UE shall transmit UCI using the shortened PUCCH format as defined in Clauses 5.4.2B, 5.4.2C, and 5.4A.4 of [3].

For PUCCH format 1/1a/1b/3, this shortened PUCCH format shall be used in a cell specific SRS subframe or the last slot/subslot of the cell specific SRS subframe of the primary cell even if the UE does not transmit SRS in that subframe. For PUCCH format 4/5, this shortened PUCCH format shall be used if the PUCCH transmission partly or fully overlaps with the cell-specific SRS bandwidth in the cell specific SRS subframes or the last slot/subslot of the cell specific SRS subframes of the primary cell even if the UE does not transmit SRS in that subframe, or if the UE transmits SRS in the last symbol of that subframe even if the PUCCH format 4/5 does not partly or fully overlap with the cell-specific SRS. The cell specific SRS subframes are defined in Clause 5.5.3.3 of [3]. Otherwise, the UE shall use the normal PUCCH format 1/1a/1b as defined in Clause 5.4.1, and 5.4A.2 of [3] or normal PUCCH format 3 as defined in Clause 5.4.2A, and 5.4A.3 or normal PUCCH format 4 as defined in Clause 5.4.2B, and 5.4A.4 or normal PUCCH format 5 as defined in Clause 5.4.2C of [3].

For a BL/CE UE not configured with the higher layer parameter srs-UpPtsAdd, for a SRS transmission in subframe n and if the UE transmits PUSCH/PUCCH in subframe n and/or n+1, the UE shall not transmit the SRS in subframe n if the SRS transmission bandwidth in subframe n is not completely within the narrowband of PUSCH/PUCCH in subframe n and/or n+1

A BL/CE UE not configured with the higher layer parameter srs-UpPtsAdd shall not transmit SRS in UpPTS if SRS frequency location is different from DwPTS reception narrowband in the same special subframe.

For a BL/CE UE, the SRS transmission that falls into the reserved symbol of a BL/CE UL subframe is dropped.

For a TDD serving cell, , not configured for PUSCH/PUCCH transmission, the UE is not expected to be configured with SRS resource(s) such that the SRS transmission (including any interruption due to uplink or downlink RF retuning time [10]) may overlap in time with PDCCH monitoring in subframes 0 or 5 on serving cell , if the UE is not capable of simultaneous transmission and reception on serving cell and serving cell .

Trigger type 0 SRS configuration of a UE in a serving cell for SRS periodicity,, and SRS subframe offset,, is defined in Table 8.2-1 and Table 8.2-2, for FDD and TDD serving cell, respectively. The periodicity of the SRS transmission is serving cell specific and is selected from the set {2, 5, 10, 20, 40, 80, 160, 320} ms or subframes.
For the SRS periodicity of 2 ms in TDD serving cell configured for PUSCH and/or PUCCH transmission, two SRS resources are configured in a half frame containing UL subframe(s) of the given serving cell. For the SRS periodicity of 2 ms in TDD serving cell not configured for PUSCH/PUCCH transmission, two or more SRS resources are configured in a half frame containing UL subframe(s) of the given serving cell.

Type 0 triggered SRS transmission instances in a given serving cell for TDD serving cell with and for FDD serving cell are the subframes satisfying , where for FDD is the subframe index within the frame, for TDD serving cell, if the UE is configured with the parameter srs-UpPtsAdd for trigger type 0, is defined in Table 8.2-6; otherwise is defined in Table 8.2-3. The SRS transmission instances for TDD serving cell with are the subframes satisfying .

For TDD serving cell, and a UE configured for type 0 triggered SRS transmission in serving cell c, and the UE configured with the parameter EIMTA-MainConfigServCell-r12 for serving cell c, if the UE does not detect an UL/DL configuration indication for radio frame m (as described in Clause 13.1), the UE shall not transmit trigger type 0 SRS in a subframe of radio frame m that is indicated by the parameter eimta-HARQ-ReferenceConfig-r12 as a downlink subframe unless the UE transmits PUSCH in the same subframe.

For a serving cell that is not a LAA SCell, trigger type 1 SRS configuration of a UE in a serving cell for SRS periodicity,, and SRS subframe offset,, is defined in Table 8.2-4 and Table 8.2-5, for FDD and TDD serving cell, respectively; and trigger type 2 SRS configuration of a UE in a serving cell for SRS periodicity, , and SRS subframe offset,, is defined in Table 8.2-5, for TDD serving cell. The periodicity of the SRS transmission is serving cell specific and is selected from the set {2, 5, 10} ms or subframes.
For the SRS periodicity of 2 ms in TDD serving cell configured for PUSCH and/or PUCCH transmission, two SRS resources are configured in a half frame containing UL subframe(s) of the given serving cell. For the SRS periodicity of 2 ms in TDD serving cell not configured for PUSCH/PUCCH transmission, two or more SRS resources are configured in a half frame containing UL subframe(s) of the given serving cell.

For TDD serving cell configured for PUSCH and/or PUCCH transmission, and a UE configured for type 1/2 triggered SRS transmission in serving cell c and configured with the parameter srs-UpPtsAdd, the UE is not expected to receive trigger type 1/2 SRS configurations with SRS periodicity of 2 ms.

A UE configured for type 1/2 triggered SRS transmission in serving cell c and not configured with a carrier indicator field shall transmit SRS on serving cell c upon detection of a positive SRS request in PDCCH/EPDCCH/MPDCCH/SPDCCH scheduling PUSCH/PDSCH on serving cell c.

A UE configured for type 1/2 triggered SRS transmission in serving cell c and configured with a carrier indicator field shall transmit SRS on serving cell c upon detection of a positive SRS request in PDCCH/EPDCCH/SPDCCH scheduling PUSCH/PDSCH with the value of carrier indicator field corresponding to serving cell c.

For a serving cell that is not a LAA SCell, a non-BL/CE UE configured for type 1/2 triggered SRS transmission on serving cell c upon detection of a positive SRS request in subframe n, slot 2n or slot 2n+1 of serving cell c shall commence SRS transmission in the first subframe satisfying , and

– if the positive SRS request in PDCCH/SPDCCH with DCI format 7-0A/7-1A is detected in slot 2n or slot 2n+1, for TDD

– if the UE is configured with higher layer parameter shortProcessingTime and the corresponding PDCCH with CRC scrambled by C-RNTI with DCI format other than DCI format 7-0A/7-0B/7-1E/7-1F/7-1G is in the UE-specific search space,

– otherwise, and

for TDD serving cell c with and for FDD serving cell c,

for TDD serving cell c with

where for FDD serving cell c is the subframe index within the frame , for TDD serving cell c, if the UE is configured with the parameter srs-UpPtsAdd for trigger type 1, is defined in Table 8.2-6; otherwise is defined in Table 8.2-3. For a TDD serving cell not configured for PUSCH/PUCCH transmission and the positive SRS request detected in PDCCH/EPDCCH scheduling PDSCH and the UE configured with soundingRS-FlexibleTiming-r14 by higher layer signalling, if the trigger type 1 SRS transmission (including any interruption due to uplink or downlink RF retuning time [10]) in the first subframe happens to overlap with a HARQ-ACK transmission for any serving cell, the UE shall commence trigger type 1 SRS transmission in subframe n + k + l, where l = max( 5, ). The soundingRS-FlexibleTiming-r14 if configured by higher layer signaling is not applied to trigger type 2 SRS.

For a type 1/2 SRS triggered for more than one TDD serving cell in DCI format 3B and UE configured with more than 5 TDD serving cells without PUSCH/PUCCH transmission, the order of the triggered SRS transmission on the serving cells follow the order of the serving cells in the indicated set of serving cells configured by higher layers. For a type 1/2 SRS triggered for more than one TDD serving cell in DCI format 3B and UE configured with no more than 5 TDD serving cells without PUSCH/PUCCH transmission, the order of the triggered SRS transmission on the serving cells follow the order of the serving cells with type 1/2 SRS triggered in the DCI. The SRS resource for the n-th (n>=2) SRS transmission is determined such that it is the first SRS resource on or after the SRS resource for the (n-1)-th SRS transmission provided it does not collide with any previous SRS transmission triggered in the DCI format 3B, or interruption due to UL or DL RF retuning time [10].

For a serving cell c that is a LAA SCell, a UE configured for type 1 triggered SRS transmission on serving cell c upon detection of a positive SRS request in subframe n of serving cell c shall commence SRS transmission, conditioned on the channel access procedures described in clause 4.2.1 of [13], in subframe , where

  • corresponds to the scheduled PUSCH subframe determined in Clause 8.0 if SRS is triggered in DCI format 0A/4A,
  • is determined from Table 8.2-0A and the corresponding scheduled PUSCH subframe determined in Clause 8.0 if SRS is triggered in DCI format 0B,
  • where the value of l is determined from SRS subframe parameter for the indicated SRS parameter set in Table 8.1, is determined from the first scheduled PUSCH subframe determined in Clause 8.0 and N is determined by the procedure in Clause 8.0 if SRS is triggered in DCI format 4B,
  • where the value of l is determined by the SRS timing offset field in the corresponding DCI if SRS is triggered in DCI format 1A/2B/2C/2D according to Table 8.2-0B.

Table 8.2-0B: for SRS trigger type 1/2 in DCI format 1A/2B/2C/2D

Value of SRS timing offset field

‘000’

No type 1/2 SRS trigger

‘001’

1

‘010’

2

‘011’

3

‘100’

4

‘101’

5

‘110’

6

‘111’

7

A BL/CE UE configured for type 1 triggered SRS transmission on serving cell c upon detection of a positive SRS request of serving cell c shall commence SRS transmission in the first subframe satisfying , , where subframe n is the last subframe in which the DCI format 6-0A/6-1A with the positive SRS request is transmitted, and

for TDD serving cell c with and for FDD serving cell c,

for TDD serving cell c with where for FDD serving cell c is the subframe index within the frame , for TDD serving cell c , if the UE is configured with the parameter srs-UpPtsAdd for trigger type 1, is defined in Table 8.2-6; otherwise is defined in Table 8.2-3.

A UE configured for type 1/2 triggered SRS transmission is not expected to receive type 1/2 SRS triggering events associated with different values of trigger type 1/2 SRS transmission parameters, as configured by higher layer signalling, for the same subframe and the same serving cell.

For a serving cell that is a LAA SCell, a UE configured for type 1 triggered SRS transmission is not expected to receive type 1 SRS triggering event in DCI format 0B associated with a subframe that is not scheduled for PUSCH transmission for the same serving cell.

For a serving cell that is an LAA SCell, if the uplink transmission in a subframe is ending in the end of symbol #3 or in the end of symbol #6, the UE shall not transmit SRS in that subframe.

A UE configured for type 2, type 1, or type 0 triggered SRS transmission and more than one TDD serving cell without PUSCH/PUCCH transmission is not expected to receive type 2, type 1, or type 0 SRS triggering events that can result in uplink transmissions beyond the UE’s indicated uplink carrier aggregation capability included in the UE-EUTRA-Capability [12].

For TDD serving cell c, and a UE configured with EIMTA-MainConfigServCell-r12 for a serving cell c, the UE shall not transmit SRS in a subframe of a radio frame that is indicated by the corresponding eIMTA-UL/DL-configuration as a downlink subframe.

A UE shall not transmit SRS whenever SRS and a PUSCH transmission corresponding to a Random Access Response Grant or a retransmission of the same transport block as part of the contention based random access procedure coincide in the same subframe.

A UE not configured with higher layer parameter ul-STTI-Length is not expected to be triggered with trigger type 2 SRS transmission in the same subframe as a PUSCH/PUCCH transmission in the same serving cell.

A UE configured with higher layer parameter ul-STTI-Length shall drop the trigger type 2 SRS transmission in the overlapped symbol when the trigger type 2 SRS transmission and slot PUSCH/PUCCH transmission happens to overlap in the same symbol and same serving cell.

A UE shall not transmit trigger type 2 SRS when trigger type 2 SRS transmission and PRACH happen to overlap in the same subframe and same serving cell.

Table 8.2-1: UE Specific SRS Periodicity and Subframe Offset Configuration
for trigger type 0, FDD

SRS Configuration Index ISRS

SRS Periodicity (ms)

SRS Subframe Offset

0 – 1

2

ISRS

2 – 6

5

ISRS – 2

7 – 16

10

ISRS – 7

17 – 36

20

ISRS – 17

37 – 76

40

ISRS – 37

77 – 156

80

ISRS – 77

157 – 316

160

ISRS – 157

317 – 636

320

ISRS – 317

637 – 1023

reserved

reserved

Table 8.2-2: UE Specific SRS Periodicity and Subframe Offset Configuration
for trigger type 0, TDD

SRS Configuration Index

ISRS

SRS Periodicity

(ms)

SRS Subframe Offset

0

2

0, 1

1

2

0, 2

2

2

1, 2

3

2

0, 3

4

2

1, 3

5

2

0, 4

6

2

1, 4

7

2

2, 3

8

2

2, 4

9

2

3, 4

10 – 14

5

ISRS – 10

15 – 24

10

ISRS – 15

25 – 44

20

ISRS – 25

45 – 84

40

ISRS – 45

85 – 164

80

ISRS – 85

165 – 324

160

ISRS – 165

325 – 644

320

ISRS – 325

645 – 1023

reserved

reserved

Table 8.2-3: for TDD

subframe index n

0

1

2

3

4

5

6

7

8

9

1st symbol of UpPTS

2nd symbol of UpPTS

1st symbol of UpPTS

2nd symbol of UpPTS

in case UpPTS length of 2 symbols

0

1

2

3

4

5

6

7

8

9

in case UpPTS length of 1 symbol

1

2

3

4

6

7

8

9

Table 8.2-4: UE Specific SRS Periodicity and Subframe Offset Configuration
for trigger type 1, FDD

SRS Configuration Index
ISRS

SRS Periodicity
(ms)

SRS Subframe Offset

0 – 1

2

ISRS

2 – 6

5

ISRS – 2

7 – 16

10

ISRS – 7

17 – 31

reserved

reserved

Table 8.2-5: UE Specific SRS Periodicity and Subframe Offset Configuration
for trigger type 1/2, TDD

SRS Configuration Index
ISRS

SRS Periodicity
(ms)

SRS Subframe Offset

0

reserved

reserved

1

2

0, 2

2

2

1, 2

3

2

0, 3

4

2

1, 3

5

2

0, 4

6

2

1, 4

7

2

2, 3

8

2

2, 4

9

2

3, 4

10 – 14

5

ISRS – 10

15 – 24

10

ISRS – 15

25 – 31

reserved

reserved

Table 8.2-6: for TDD and UE configured with two or four additional SC-FDMA symbols in UpPTS

subframe index n

0

1

2

3

4

5

6

7

8

9

1st symbol of UpPTS

2nd symbol of UpPTS

3rd symbol of UpPTS

4th symbol of UpPTS

1st symbol of UpPTS

2nd symbol of UpPTS

3rd symbol of UpPTS

4th symbol of UpPTS

in case UpPTS length of 4 symbols

0

1

2

3

5

6

7

8

in case UpPTS length of 2 symbols

2

3

7

8