7.2.3 Channel Quality Indicator (CQI) definition
36.2133GPPEvolved Universal Terrestrial Radio Access (E-UTRA)Physical layer proceduresRelease 17TS
The CQI indices and their interpretations are given in Table 7.2.3-1, Table 7.2.3-5, Table 7.2.3-6 for reporting CQI based on QPSK, 16QAM and 64QAM. The CQI indices and their interpretations are given in Table 7.2.3-2 for reporting CQI based on QPSK, 16QAM, 64QAM and 256QAM. The CQI indices and their interpretations are given in Table 7.2.3-3 for reporting CQI based on QPSK and 16QAM. The CQI indices and their interpretations are given in Table 7.2.3-4 for reporting CQI based on QPSK, 16QAM, 64QAM, 256QAM, and 1024QAM.
For a non-BL/CE UE, based on an unrestricted observation interval in time unless specified otherwise in this Clause, and an unrestricted observation interval in frequency, the UE shall derive for each CQI value reported in uplink subframe/slot/subslot n the highest CQI index between 1 and 15 in Table 7.2.3-1, Table 7.2.3-2 or Table 7.2.3-4 which satisfies the following condition, or CQI index 0 if CQI index 1 does not satisfy the condition:
– A single PDSCH transport block with a combination of modulation scheme and transport block size corresponding to the CQI index, and occupying a group of downlink physical resource blocks termed the CSI reference resource, could be received with a transport block error probability not exceeding 0.1.
For a BL/CE UE, based on an unrestricted observation interval in time and frequency, the UE shall derive for each CQI value the highest CQI index in Table 7.2.3-3, Table 7.2.3-5 or Table 7.2.3-6 which satisfies the following condition, or CQI index 0 if CQI index 1 does not satisfy the condition:
– A single PDSCH transport block with a combination of modulation scheme and transport block size corresponding to the CQI index, and occupying a group of downlink physical resource blocks termed the CSI reference resource, could be received with a transport block error probability not exceeding 0.1.
If CSI subframe sets and are configured by higher layers, each CSI reference resource belongs to either or but not to both. When CSI subframe sets and are configured by higher layers a UE is not expected to receive a trigger for which the CSI reference resource is in subframe that does not belong to either subframe set. For a UE in transmission mode 10 and periodic CSI reporting, the CSI subframe set for the CSI reference resource is configured by higher layers for each CSI process.
If the UE is configured with parameter eMIMO-Type2 by higher layers for a CSI process, for computing the CQI value for eMIMO-Type2 of the CSI process, the parameter eMIMO-Type in the rest of this Clause refers to the parameter eMIMO-Type2 for the CSI process.
For a UE in transmission mode 9 when parameter pmi-RI-Report is configured by higher layers and parameter eMIMO-Type is not configured by higher layers, the UE shall derive the channel measurements for computing the CQI value reported in uplink subframe/slot/subslot n based on only the Channel-State Information (CSI) reference signals (CSI-RS) defined in [3] for which the UE is configured to assume non-zero power for the CSI-RS. For a non-BL/CE UE in transmission mode 9 when the parameter pmi-RI-Report is not configured by higher layers or in transmission modes 1-8 the UE shall derive the channel measurements for computing CQI based on CRS. For a BL/CE UE, the UE shall derive the channel measurements for computing CQI based on CSI-RS if configured with the higher layer parameter ce-CSI-RS-Feedback for transmission mode 9 and the number of CSI-RS ports=8, otherwise based on CRS.
For a UE in transmission mode 10, when parameter eMIMO-Type is not configured by higher layers, the UE shall derive the channel measurements for computing the CQI value reported in uplink subframe/slot/subslot n and corresponding to a CSI process, based on only the non-zero power CSI-RS (defined in [3]) within a configured CSI-RS resource associated with the CSI process.
For a UE in transmission mode 9 and the UE configured with parameter eMIMO-Type by higher layers, the term ‘CSI process’ in this clause refers to the CSI configured for the UE.
For a UE in transmission mode 9 or 10 and for a CSI process, if the UE is configured with parameter eMIMO-Type by higher layers, and eMIMO-Type is set to ‘CLASS A’, and one CSI-RS resource configured, or the UE is configured with parameter eMIMO-Type by higher layers, and eMIMO-Type is set to ‘CLASS B’, and parameter channelMeasRestriction is not configured by higher layers, the UE shall derive the channel measurements for computing the CQI value reported in uplink subframe n and corresponding to the CSI process, based on only the non-zero power CSI-RS (defined in [3]) within a configured CSI-RS resource associated with the CSI process. If the UE is configured with parameter eMIMO-Type by higher layers, except with higher layer parameter csi-RS-NZP-mode configured, and eMIMO-Type is set to ‘CLASS B’ and the number of configured CSI-RS resources is K>1, and parameter channelMeasRestriction is not configured by higher layers, the UE shall derive the channel measurements for computing the CQI value using only the configured CSI-RS resource indicated by the CRI. If the UE is configured with higher layer parameter eMIMO-Type set to ‘CLASS B’ and higher layer parameter csi-RS-NZP-mode set to ‘multiShot’, and the number of activated CSI-RS resources is more than one, and parameter channelMeasRestriction is not configured by higher layers, the UE shall derive the channel measurements for computing the CQI value using only the activated CSI-RS resource indicated by CRI.
For a UE in transmission mode 9 or 10 and for a CSI process, if the UE is configured with parameter eMIMO-Type by higher layers, and eMIMO-Type is set to ‘CLASS B’, and parameter channelMeasRestriction is configured by higher layers, the UE shall derive the channel measurements for computing the CQI value reported in uplink subframe n and corresponding to the CSI process, based on only the most recent, no later than the CSI reference resource, non-zero power CSI-RS (defined in [3]) within a configured CSI-RS resource associated with the CSI process. If the UE is configured with parameter eMIMO-Type by higher layers, except with higher layer parameter csi-RS-NZP-mode configured, and eMIMO-Type is set to ‘CLASS B’ and the number of configured CSI-RS resources is K>1, and parameter channelMeasRestriction is configured by higher layers, the UE shall derive the channel measurements for computing the CQI value using only the most recent, no later than the CSI reference resource, non-zero power CSI-RS within the configured CSI-RS resource indicated by the CRI. If the UE is configured with higher layer parameter eMIMO-Type set to ‘CLASS B’ and higher layer parameter csi-RS-NZP-mode set to ‘multiShot’, and the number of activated CSI-RS resources is more than one, and parameter channelMeasRestriction is configured by higher layers, the UE shall derive the channel measurements for computing the CQI value using only the most recent, no later than the CSI reference resource, non-zero power CSI-RS within the activated CSI-RS resource indicated by the CRI.
For a UE in transmission mode 10, when parameter eMIMO-Type is not configured by higher layers, the UE shall derive the interference measurements for computing the CQI value reported in uplink subframe/slot/subslot n and corresponding to a CSI process, based on only the configured CSI-IM resource associated with the CSI process.
For a UE in transmission mode 10 and for a CSI process, when parameters eMIMO-Type and interferenceMeasRestriction is configured by higher layers, the UE shall derive the interference measurements for computing the CQI value reported in uplink subframe n and corresponding to the CSI process, based on only the most recent, no later than the CSI reference resource, configured CSI-IM resource associated with the CSI process. If the UE is configured with parameter eMIMO-Type by higher layers, except with higher layer parameter csi-RS-NZP-mode configured, and eMIMO-Type is set to ‘CLASS B’ and the number of configured CSI-RS resources is K>1, and interferenceMeasRestriction is configured, the UE shall derive interference measurement for computing the CQI value based on only the most recent, no later than the CSI reference resource, the configured CSI-IM resource associated with the CSI-RS resource indicated by the CRI. If the UE is configured with higher layer parameter eMIMO-Type set to ‘CLASS B’ and higher layer parameter csi-RS-NZP-mode set to ‘multiShot’, and the number of activated CSI-RS resources is K>1, and interferenceMeasRestriction is configured, the UE shall derive interference measurement for computing the CQI value based on only the most recent, no later than the CSI reference resource, the configured CSI-IM resource associated with the activated CSI-RS resource indicated by the CRI. If interferenceMeasRestriction is not configured, the UE shall derive the interference measurement for computing the CQI value based on the CSI-IM associated with the CSI-RS resource indicated by the CRI.
If the UE in transmission mode 10 is configured by higher layers for CSI subframe sets and for the CSI process, the configured CSI-IM resource within the subframe subset belonging to the CSI reference resource is used to derive the interference measurement.
For a UE configured with the parameter EIMTA-MainConfigServCell-r12 for a serving cell, configured CSI-IM resource(s) within only downlink subframe(s) of a radio frame that are indicated by UL/DL configuration of the serving cell can be used to derive the interference measurement for the serving cell.
For a LAA Scell,
– for channel measurements, if the UE averages CRS/CSI-RS measurements from multiple subframes
– the UE should not average CSI-RS measurement in subframe n1 with CSI-RS measurement in a later subframe n2, if any OFDM symbol of subframe n1 or any subframe from subframe n1+1 to subframe n2, is not occupied.
– the UE should not average CRS measurement in subframe n1 with CRS measurement in a later subframe n2, if any OFDM symbol of the second slot of subframe n1 or any OFDM symbol of any subframe from subframe n1+1 to subframe n2-1, or any of the first 3 OFDM symbols in subframe n2, is not occupied.
– for interference measurements, the UE shall derive the interference measurements for computing the CQI value based on only measurements in subframes with occupied OFDM symbols.
A combination of modulation scheme and transport block size corresponds to a CQI index if:
– the combination could be signalled for transmission on the PDSCH in the CSI reference resource according to the relevant Transport Block Size table, and
– the modulation scheme is indicated by the CQI index, and
– the combination of transport block size and modulation scheme when applied to the reference resource results in the effective channel code rate which is the closest possible to the code rate indicated by the CQI index. If more than one combination of transport block size and modulation scheme results in an effective channel code rate equally close to the code rate indicated by the CQI index, only the combination with the smallest of such transport block sizes is relevant.
The CSI reference resource for a serving cell is defined as follows:
– For a non-BL/CE UE, in the frequency domain, the CSI reference resource is defined by the group of downlink physical resource blocks corresponding to the band to which the derived CQI value relates. For a BL/CE UE, in the frequency domain, the CSI reference resource includes all downlink physical resource blocks for any of the narrowband to which the derived CQI value relates.
– In the time domain and for a non-BL/CE UE,
– for a UE configured in transmission mode 1-9 or transmission mode 10 with a single configured CSI process for the serving cell, the CSI reference resource is defined by a single downlink subframe/slot/subslot or special subframe or a slot in a special subframe n–nCQI_ref,
– where for periodic CSI reporting nCQI_ref is the smallest value greater than or equal to 
, such that it corresponds to a valid downlink or valid special subframe,
– where for aperiodic CSI reporting, if the UE is not configured with the higher layer parameter csi-SubframePatternConfig-r12, and
– where for LAA serving cell,
– if aperiodic CSI reporting is triggered by DCI format 0A/0B/4A/4B with ‘PUSCH trigger A’ set to 1,
– nCQI_ref is the smallest value greater than or equal to , such that subframe n–nCQI_ref corresponds to a valid downlink subframe no later than the subframe in which DCI format 0A/0B/4A/4B with ‘PUSCH trigger A’ set to 1 is received.
– if aperiodic CSI reporting is triggered by DCI format 0A/0B/4A/4B with ‘PUSCH trigger A’ set to 0,
– nCQI_ref is the smallest value greater than or equal to , such that subframe n–nCQI_ref corresponds to a valid downlink subframe.
– otherwise,
– nCQI_ref is the smallest value greater than or equal to , such that subframe n–nCQI_ref corresponds to a valid downlink subframe.
– where for FDD serving cell or TDD serving cell,
– nCQI_ref is such that the reference resource is in the same valid downlink subframe/slot/subslot or valid special subframe or a valid slot in a special subframe as the corresponding CSI request in an uplink DCI format.
– nCQI_ref is equal to 4 and subframe n–nCQI_ref corresponds to a valid downlink or valid special subframe, where subframe n–nCQI_ref is received after the subframe with the corresponding CSI request in a Random Access Response Grant.
– where for aperiodic CSI reporting, and the UE configured with the higher layer parameter csi-SubframePatternConfig-r12,
– for the UE configured in transmission mode 1-9,
– nCQI_ref is the smallest value greater than or equal to
- for aperiodic CSI reporting on subframe-PUSCH
- 4 for aperiodic CSI reporting on slot-PUSCH if the higher layer parameter dl-TTI-Length is set to slot
for aperiodic CSI reporting on subslot-PUSCH- Subslot nCQI_ref is not later than
- subslot 0 of subframe n-2 for aperiodic CSI reporting on slot 0 of subframe n
- subslot 3 of subframe n-2 for aperiodic CSI reporting on slot 1 of subframe n
if the higher layer parameter dl-TTI-Length is set to ‘subslot’, and the higher layer parameter ul-TTI-Length is set to ‘slot’
and subframe/slot/subslot n–nCQI_ref corresponds to a valid downlink subframe/slot/subslot or valid special subframe or a valid slot in a special subframe, where subframe/slot/subslot n–nCQI_ref is received on or after the subframe/slot/subslot with the corresponding CSI request in an uplink DCI format;
– nCQI_ref is the smallest value greater than or equal to 4, and subframe n–nCQI_ref corresponds to a valid downlink or valid special subframe, where subframe n–nCQI_ref is received after the subframe with the corresponding CSI request in a Random Access Response Grant;
– if there is no valid value for nCQI_ref based on the above conditions, then nCQI_ref is the smallest value such that the reference resource is in a valid downlink subframe/slot/subslot or valid special subframe or a valid slot in a special subframe n–nCQI_ref prior to the subframe/slot/subslot with the corresponding CSI request, where subframe/slot/subslot n–nCQI_ref is the lowest indexed valid downlink subframe/slot/subslot or valid special subframe or a valid slot in a special subframe within a radio frame;
– for the UE configured in transmission mode 10,
– nCQI_ref is the smallest value greater than or equal to
- for aperiodic CSI reporting on subframe-PUSCH,
- 4 for aperiodic CSI reporting on slot-PUSCH if the higher layer parameter dl-TTI-Length is set to slot
for aperiodic CSI reporting on subslot-PUSCH- Subslot nCQI_ref is not later than
- subslot 0 of subframe n-2 for aperiodic CSI reporting on slot 0 of subframe n
- subslot 3 of subframe n-2 for aperiodic CSI reporting on slot 1 of subframe n
if the higher layer parameter dl-TTI-Length is set to ‘subslot’, and the higher layer parameter ul-TTI-Length is set to ‘slot’such that it corresponds to a valid downlink subframe/slot/subslot or valid special subframe or a valid slot in a special subframe, and the corresponding CSI request is in an uplink DCI format;
– nCQI_ref is the smallest value greater than or equal to 4, and subframe n–nCQI_ref corresponds to a valid downlink or valid special subframe, where subframe n–nCQI_ref is received after the subframe with the corresponding CSI request in a Random Access Response Grant;
– for a UE configured in transmission mode 10 with multiple configured CSI processes for the serving cell, the CSI reference resource for a given CSI process is defined by a single downlink subframe/slot/subslot or special subframe or a valid slot in a special subframe n–nCQI_ref,
– where for FDD serving cellsubslot nCQI_ref is not later than
– subslot 5 of subframe n-3 for aperiodic CSI reporting on slot 0 of subframe n
– subslot 2 of subframe n-2 for aperiodic CSI reporting on slot 1 of subframe n
if the higher layer parameter dl-TTI-Length is set to subslot, and the higher layer parameter ul-TTI-Length is set to slot
– nCQI_ref is the smallest value greater than or equal to
– 5 for aperiodic CSI reporting on slot-PUSCH if the higher layer parameter dl-TTI-Length is set to ‘slot’
– for aperiodic CSI reporting on subslot-PUSCH,
– +1, otherwise
such that it corresponds to a valid downlink subframe/slot/subslot or valid special subframe or a valid slot in a special subframe, and for aperiodic CSI reporting the corresponding CSI request is in an uplink DCI format;
– where for FDD serving cell and aperiodic CSI reporting nCQI_ref is equal to 5 and subframe n–nCQI_ref corresponds to a valid downlink or valid special subframe, where subframe n–nCQI_ref is received after the subframe with the corresponding CSI request in a Random Access Response Grant.
– where for TDD serving cell, and 2 or 3 configured CSI processes, and periodic or aperiodic CSI reporting, nCQI_ref is the smallest value greater than or equal to 4 for aperiodic CSI reporting on slot-based PUSCH, and otherwise, such that it corresponds to a valid downlink or valid special subframe or a valid slot in a special subframe, and for aperiodic CSI reporting the corresponding CSI request is in an uplink DCI format;
– where for TDD serving cell, and 2 or 3 configured CSI processes, and aperiodic CSI reporting, nCQI_ref is equal to 4 and subframe n–nCQI_ref corresponds to a valid downlink or valid special subframe, where subframe n–nCQI_ref is received after the subframe with the corresponding CSI request in a Random Access Response Grant;
– where for TDD serving cell, and 4 configured CSI processes, and periodic or aperiodic CSI reporting, nCQI_ref is the smallest value greater than or equal to 5 for aperiodic CSI reporting on slot-based PUSCH, and 
otherwise, such that it corresponds to a valid downlink or valid special subframe or a valid slot in a special subframe, and for aperiodic CSI reporting the corresponding CSI request is in an uplink DCI format;
– where for TDD serving cell, and 4 configured CSI processes, and aperiodic CSI reporting, nCQI_ref is equal to 5 and subframe n–nCQI_ref corresponds to a valid downlink or valid special subframe, where subframe n–nCQI_ref is received after the subframe with the corresponding CSI request in a Random Access Response Grant.
– where for LAA serving cell and periodic CSI reporting, nCQI_ref is the smallest value greater than or equal to 
, such that it corresponds to a valid downlink subframe.
– where for LAA serving cell and aperiodic CSI reporting, and
– if aperiodic CSI reporting is triggered by DCI format 0A/0B/4A/4B with ‘PUSCH trigger A’ set to 1,
– nCQI_ref is the smallest value greater than or equal to +1, such that subframe n–nCQI_ref corresponds to a valid downlink subframe no later than the subframe in which DCI format 0A/0B/4A/4B with ‘PUSCH trigger A’ set to 1 is received.
– if aperiodic CSI reporting is triggered by DCI format 0A/0B/4A/4B with ‘PUSCH trigger A’ set to 0,
– nCQI_ref is the smallest value greater than or equal to +1, such that subframe n–nCQI_ref corresponds to a valid downlink subframe.
– otherwise,
– nCQI_ref is the smallest value greater than or equal to 5, such that subframe n–nCQI_ref corresponds to a valid downlink subframe.
– In the time domain and for a BL/CE UE, the CSI reference resource is defined by a set of BL/CE downlink or special subframes where the last subframe is subframe n–nCQI_ref -Koffset,
– where is given by,
– if the UE is configured with the higher layer parameter CellSpecificKoffset,
– where
is the parameter CellSpecificKoffset provided by higher layers, and
is the parameter UESpecificKoffset provided by higher layers, otherwise
– otherwise,
– ;
– where for periodic CSI reporting nCQI_ref is ≥ 4;
– where for aperiodic CSI reporting nCQI_ref is ≥ 4;
where each subframe in the CSI reference resource is a valid downlink or valid special subframe;
– where for wideband CSI reports:
– The set of BL/CE downlink or special subframes is the set of the last subframes before n–nCQI_ref –Koffset used for MPDCCH monitoring by the BL/CE UE in each of the narrowbands where the BL/CE UE monitors MPDCCH, where is the number of narrowbands where the BL/CE UE monitors MPDCCH.
– where for subband CSI reports:
– The set of BL/CE downlink or special subframes is the set of the last subframes used for MPDCCH monitoring by the BL/CE UE in the corresponding narrowband before n–nCQI_ref –Koffset;
– where is given by the "repetition" column when UE is configured to report the CQI according to Table 7.2.3-6, otherwise by the higher layer parameter csi-NumRepetitionCE.
A subframe/slot/subslot in a serving cell shall be considered to be a valid downlink subframe/slot/subslot or a valid special subframe or a valid slot in a special subframe if:
– it is configured as a downlink subframe/slot/subslot or a special subframe or a slot in a special subframe for that UE, and
– in case multiple cells with different uplink-downlink configurations are aggregated and the UE is not capable of simultaneous reception and transmission in the aggregated cells, the subframe/slot/subslot in the primary cell is a downlink subframe or a special subframe with the length of DwPTS more than for subframe-based transmissions, or the slot is a first slot of DwPTS for special subframe configurations 1,2,3,4,6,7,8,9,10, or the second slot of DwPTS for special subframe configurations 3,4,8 for slot-based transmissions, and
– except for a non-BL/CE UE in transmission mode 9 or 10, the subframe/slot/subslot is not in an MBSFN subframe, and
– in case of TDD
– and subframe-based transmissions, the subframe does not contain a DwPTS field in case the length of DwPTS is and less,
– and slot-based transmission,
– the slot is not a slot of DwPTS for special subframe configurations 0, 5,
– the slot is not the second slot of DwPTS for special subframe configurations 1, 2, 6, 7.
– it is not a special subframe with special subframe configuration 10 configured by ssp10-CRS-LessDwPTS, and
– it does not fall within a configured measurement gap for that UE, and
– for periodic CSI reporting, it is an element of the CSI subframe set linked to the periodic CSI report when that UE is configured with CSI subframe sets, and
– for a UE configured in transmission mode 10 with multiple configured CSI processes, and aperiodic CSI reporting for a CSI process, it is an element of the CSI subframe set linked to the downlink or special subframe containing the subframe/slot/subslot with the corresponding CSI request in an uplink DCI format, when that UE is configured with CSI subframe sets for the CSI process and UE is not configured with the higher layer parameter csi-SubframePatternConfig-r12, and
– for a UE configured in transmission mode 1-9, and aperiodic CSI reporting, it is an element of the CSI subframe set associated with the corresponding CSI request in an uplink DCI format, when that UE is configured with CSI subframe sets by the higher layer parameter csi-SubframePatternConfig-r12, and
– for a UE configured in transmission mode 10, and aperiodic CSI reporting for a CSI process, it is an element of the CSI subframe set associated with the corresponding CSI request in an uplink DCI format, when that UE is configured with CSI subframe sets by the higher layer parameter csi-SubframePatternConfig-r12 for the CSI process.
– except if the serving cell is a LAA Scell, and at least one OFDM symbol in the subframe is not occupied.
– except if the serving cell is a LAA Scell, and as described in sub clause 6.10.1.1 in [3].
– except if the serving cell is a LAA Scell, and for a UE configured in transmission mode 9 or 10, the configured CSI-RS resource associated with the CSI process is not in the subframe.
For a non-BL/CE UE, if there is no valid downlink subframe/slot/subslot or no valid special subframe or no valid slot in a special subframe for the CSI reference resource in a serving cell, CSI reporting is omitted for the serving cell in uplink subframe/slot/subslot n.
– In the layer domain, the CSI reference resource is defined by any RI and PMI on which the CQI is conditioned.
In the CSI reference resource, the UE shall assume the following for the purpose of deriving the CQI index, and if also configured, PMI and RI except when the CSI request field from an uplink DCI format 7-0A/7-0B is set to trigger a report:
– The first 3 OFDM symbols are occupied by control signalling
– No resource elements used by primary or secondary synchronization signals or PBCH or EPDCCH
– CP length of the non-MBSFN subframes
– Redundancy Version 0
– If CSI-RS is used for channel measurements, the ratio of PDSCH EPRE to CSI-RS EPRE is as given in Clause 7.2.5
– For transmission mode 9 CSI reporting of a non-BL/CE UE:
– CRS REs are as in non-MBSFN subframes;
– If the UE is configured for PMI/RI reporting or without PMI reporting, the UE-specific reference signal overhead is consistent with the most recent reported rank if more than one CSI-RS port is configured, and is consistent with rank 1 transmission if only one CSI-RS port is configured; and PDSCH signals on antenna ports for layers would result in signals equivalent to corresponding symbols transmitted on antenna ports , as given by,
if the UE is configured with higher layer parameter semiOpenLoop,
for
for
where is a vector of symbols from the layer mapping in clause 6.3.3.2 of [3], is the number of CSI-RS ports configured, and if UE reports a PMI, where associated with PMI codebook Table 7.2.4-0A and Table 7.2.4-0B for 4 antenna ports when alternativeCodeBookEnabledFor4TX-r12=TRUE is configured, associated with PMI codebook Table 7.2.4-1 and Table 7.2.4-2 for 8 antenna ports when higher layer parameter eMIMO-Type is not configured, associated with PMI codebook Table 7.2.4-10 and Table 7.2.4-11 for 8/12/16/20/24/28/32 antenna ports when higher layer parameter eMIMO-Type is configured, and where is the column vector associated with the reported first PMI i1 and the second PMI i2 configured according to codebook subset restriction, and otherwise is the selected precoding matrix corresponding to the reported CQI applicable to . The corresponding PDSCH signals transmitted on antenna ports would have a ratio of EPRE to CSI-RS EPRE equal to the ratio given in clause 7.2.5,
otherwise,
,
where is a vector of symbols from the layer mapping in Clause 6.3.3.2 of [3], is the number of CSI-RS ports configured, and if only one CSI-RS port is configured, is 1, otherwise for UE configured for PMI/RI reporting is the precoding matrix corresponding to the reported PMI applicable to and for UE configured without PMI reporting is the selected precoding matrix corresponding to the reported CQI applicable to . The corresponding PDSCH signals transmitted on antenna ports would have a ratio of EPRE to CSI-RS EPRE equal to the ratio given in Clause 7.2.5.
– For transmission mode 10 CSI reporting, if a CSI process is configured without PMI/RI reporting:
– If the number of antenna ports of the associated CSI-RS resource is one, a PDSCH transmission is on single-antenna port, port 7. The channel on antenna port {7} is inferred from the channel on antenna port {15} of the associated CSI-RS resource.
– CRS REs are as in non-MBSFN subframes. The CRS overhead is assumed to be the same as the CRS overhead corresponding to the number of CRS antenna ports of the serving cell;
– The UE-specific reference signal overhead is 12 REs per PRB pair.
– Otherwise,
– If the number of antenna ports of the associated CSI-RS resource is 2, the PDSCH transmission scheme assumes the transmit diversity scheme defined in Clause 7.1.2 on antenna ports {0,1} except that the channels on antenna ports {0,1} are inferred from the channels on antenna port {15, 16} of the associated CSI resource respectively.
– If the number of antenna ports of the associated CSI-RS resource is 4, the PDSCH transmission scheme assumes the transmit diversity scheme defined in Clause 7.1.2 on antenna ports {0,1,2,3} except that the channels on antenna ports {0,1,2,3} are inferred from the channels on antenna ports {15, 16, 17, 18} of the associated CSI-RS resource respectively.
– The UE is not expected to be configured with more than 4 antenna ports for the CSI-RS resource associated with the CSI process configured without PMI/RI reporting.
– The overhead of CRS REs is assuming the same number of antenna ports as that of the associated CSI-RS resource.
– UE-specific reference signal overhead is zero.
– For transmission mode 10 CSI reporting, if a CSI process is configured with PMI/RI reporting or without PMI reporting:
– CRS REs are as in non-MBSFN subframes. The CRS overhead is assumed to be the same as the CRS overhead corresponding to the number of CRS antenna ports of the serving cell;
– The UE-specific reference signal overhead is consistent with the most recent reported rank for the CSI process if more than one CSI-RS port is configured, and is consistent with rank 1 transmission if only one CSI-RS port is configured; and PDSCH signals on antenna ports for layers would result in signals equivalent to corresponding symbols transmitted on antenna ports , as given by,
if the UE is configured with higher layer parameter semiOpenLoop and not configured with higher layer parameter FeCoMPCSIEnabled,
for
for
where is a vector of symbols from the layer mapping in clause 6.3.3.2 of [3], is the number of CSI-RS ports configured, and if UE reports a PMI, where associated with PMI codebook Table 7.2.4-0A and Table 7.2.4-0B for 4 antenna ports when alternativeCodeBookEnabledFor4TX-r12=TRUE is configured, associated with PMI codebook Table 7.2.4-1 and Table 7.2.4-2 for 8 antenna ports when higher layer parameter eMIMO-Type is not configured, associated with PMI codebook Table 7.2.4-10 and Table 7.2.4-11 for 8/12/16/20/24/28/32 antenna ports when higher layer parameter eMIMO-Type is configured, and where is the column vector associated with the reported first PMI i1 and the second PMI i2 configured according to codebook subset restriction, and otherwise is the selected precoding matrix corresponding to the reported CQI applicable to . The corresponding PDSCH signals transmitted on antenna ports would have a ratio of EPRE to CSI-RS EPRE equal to the ratio given in clause 7.2.5,
otherwise if the UE is not configured with higher layer parameter FeCoMPCSIEnabled or the UE is configured with higher layer parameter FeCoMPCSIEnabled and UE reports CRI with value of 0 or 1,
,
where is a vector of symbols from the layer mapping in Clause 6.3.3.2 of [3], is the number of antenna ports of the associated CSI-RS resource, and if P=1,is 1, otherwise for UE configured for PMI/RI reporting is the precoding matrix corresponding to the reported PMI applicable to and for UE configured without PMI reporting is the selected precoding matrix corresponding to the reported CQI applicable to . The corresponding PDSCH signals transmitted on antenna ports would have a ratio of EPRE to CSI-RS EPRE equal to the ratio given in Clause 7.2.5,
otherwise if the UE is configured with higher layer parameter FeCoMPCSIEnabled and UE reports CRI=2 then the PDSCH signals on antenna ports corresponding to layers of codeword k would result in signals equivalent to corresponding symbols transmitted on antenna ports corresponding to the (k+1)th CSI-RS resource, where are the number of antenna ports for the (k+1)th CSI-RS resource, as given by
where is a vector of symbols from the layer mapping in Clause 6.3.3.2 of [3] for codeword k=0, 1 and where the CSI corresponding to a codeword is calculated based on the assumption that inter-codeword interference is derived from channel measurement obtained from the NZP CSI-RS resource and the precoding matrix corresponding to the other codeword. The corresponding PDSCH signals transmitted on antenna ports would have a ratio of EPRE to CSI-RS EPRE equal to the ratio given in Clause 7.2.5 for the (k+1)th CSI-RS resource. If =1, then is 1 otherwise for UE configured for PMI/RI reporting is the precoding matrix corresponding to the reported PMI applicable to and for UE configured without PMI reporting is the selected precoding matrix corresponding to the reported CQI applicable to .
– Assume no REs allocated for CSI-RS and zero-power CSI-RS
– Assume no REs allocated for PRS
– The PDSCH transmission scheme given by Table 7.2.3-0 depending on the transmission mode currently configured for the UE (which may be the default mode).
– If CRS is used for channel measurements, the ratio of PDSCH EPRE to cell-specific RS EPRE is as given in Clause 5.2 with the exception of which shall be assumed to be
– [dB] for any modulation scheme, if the UE is configured with transmission mode 2 with 4 cell-specific antenna ports, or transmission mode 3 with 4 cell-specific antenna ports and the associated RI is equal to one;
– [dB] for any modulation scheme and any number of layers, otherwise.
The shift is given by the parameter nomPDSCH-RS-EPRE-Offset which is configured by higher-layer signalling.
When the CSI request field from an uplink DCI format 7-0A/7-0B is set to trigger a report, the UE shall assume the number of available REs assumed for the reference resource for the purpose of deriving the CQI index, and if also configured, PMI and RI is:
– half of the number of available REs assumed for the reference resource when the CSI request field from an uplink DCI format other than 7-0A/7-0B is set to trigger a report if the UE is configured for slot-based uplink transmissions,
– one sixth of the number of available REs assumed for the reference resource when the CSI request field from an uplink DCI format other than 7-0A/7-0B is set to trigger a report if the UE is configured for subslot-based uplink transmissions
Table 7.2.3-0: PDSCH transmission scheme assumed for CSI reference resource
|
Transmission mode |
Transmission scheme of PDSCH |
|
1 |
Single-antenna port, port 0 |
|
2 |
Transmit diversity |
|
3 |
Transmit diversity if the associated rank indicator is 1, otherwise large delay CDD |
|
4 |
Closed-loop spatial multiplexing |
|
5 |
Multi-user MIMO |
|
6 |
Closed-loop spatial multiplexing with a single transmission layer |
|
7 |
If the number of PBCH antenna ports is one, Single-antenna port, port 0; otherwise Transmit diversity |
|
8 |
If the UE is configured without PMI/RI reporting: if the number of PBCH antenna ports is one, single-antenna port, port 0; otherwise transmit diversity. If the UE is configured with PMI/RI reporting: closed-loop spatial multiplexing. |
|
9 |
For activated serving cells, and a non-BL/CE UE, if the UE is configured without PMI/RI reporting: if the number of PBCH antenna ports is one, single-antenna port, port 0; otherwise transmit diversity. For activated serving cells, and a non-BL/CE UE, if the UE is configured with PMI/RI reporting or without PMI reporting: if the number of CSI-RS ports is one, single-antenna port, port 7; otherwise up to 8 layer transmission, ports 7-14 (see Clause 7.1.5B). For activated serving cells, and a BL/CE UE, if the UE is not configured with periodic CSI reporting mode 1-1: if the number of PBCH antenna ports is one, single-antenna port, port 0; otherwise transmit diversity. For activated serving cells, and a BL/CE UE, if the UE is configured with periodic CSI reporting mode 1-1: if the number of PBCH antenna ports is one, single-antenna port, port 0; otherwise closed-loop spatial multiplexing with a single transmission layer. For dormant serving cells: if the number of PBCH antenna ports is one, single-antenna port, port 0; otherwise transmit diversity. |
|
10 |
For activated serving cells, if a CSI process of the UE is configured without PMI/RI reporting: if the number of CSI-RS ports is one, single-antenna port, port7; otherwise transmit diversity. For activated serving cells, and if a CSI process of the UE is configured with PMI/RI reporting or without PMI reporting: if the number of CSI-RS ports is one, single-antenna port, port 7; otherwise up to 8 layer transmission, ports 7-14 (see Clause 7.1.5B). For dormant serving cells: if the number of PBCH antenna ports is one, single-antenna port, port 0; otherwise transmit diversity. |
Table 7.2.3-1: 4-bit CQI Table
|
CQI index |
modulation |
code rate x 1024 |
efficiency |
|
0 |
out of range |
||
|
1 |
QPSK |
78 |
0.1523 |
|
2 |
QPSK |
120 |
0.2344 |
|
3 |
QPSK |
193 |
0.3770 |
|
4 |
QPSK |
308 |
0.6016 |
|
5 |
QPSK |
449 |
0.8770 |
|
6 |
QPSK |
602 |
1.1758 |
|
7 |
16QAM |
378 |
1.4766 |
|
8 |
16QAM |
490 |
1.9141 |
|
9 |
16QAM |
616 |
2.4063 |
|
10 |
64QAM |
466 |
2.7305 |
|
11 |
64QAM |
567 |
3.3223 |
|
12 |
64QAM |
666 |
3.9023 |
|
13 |
64QAM |
772 |
4.5234 |
|
14 |
64QAM |
873 |
5.1152 |
|
15 |
64QAM |
948 |
5.5547 |
Table 7.2.3-2: 4-bit CQI Table 2
|
CQI index |
modulation |
code rate x 1024 |
efficiency |
|
0 |
out of range |
||
|
1 |
QPSK |
78 |
0.1523 |
|
2 |
QPSK |
193 |
0.3770 |
|
3 |
QPSK |
449 |
0.8770 |
|
4 |
16QAM |
378 |
1.4766 |
|
5 |
16QAM |
490 |
1.9141 |
|
6 |
16QAM |
616 |
2.4063 |
|
7 |
64QAM |
466 |
2.7305 |
|
8 |
64QAM |
567 |
3.3223 |
|
9 |
64QAM |
666 |
3.9023 |
|
10 |
64QAM |
772 |
4.5234 |
|
11 |
64QAM |
873 |
5.1152 |
|
12 |
256QAM |
711 |
5.5547 |
|
13 |
256QAM |
797 |
6.2266 |
|
14 |
256QAM |
885 |
6.9141 |
|
15 |
256QAM |
948 |
7.4063 |
Table 7.2.3-3: 4-bit CQI Table 3
|
CQI index |
modulation |
code rate x 1024 x
|
efficiency x
|
|
0 |
out of range |
||
|
1 |
QPSK |
40 |
0.0781 |
|
2 |
QPSK |
78 |
0.1523 |
|
3 |
QPSK |
120 |
0.2344 |
|
4 |
QPSK |
193 |
0.3770 |
|
5 |
QPSK |
308 |
0.6016 |
|
6 |
QPSK |
449 |
0.8770 |
|
7 |
QPSK |
602 |
1.1758 |
|
8 |
16QAM |
378 |
1.4766 |
|
9 |
16QAM |
490 |
1.9141 |
|
10 |
16QAM |
616 |
2.4063 |
|
11 |
Reserved |
Reserved |
Reserved |
|
12 |
Reserved |
Reserved |
Reserved |
|
13 |
Reserved |
Reserved |
Reserved |
|
14 |
Reserved |
Reserved |
Reserved |
|
15 |
Reserved |
Reserved |
Reserved |
Table 7.2.3-4: 4-bit CQI Table 4
|
CQI index |
modulation |
code rate x 1024 |
Efficiency |
|
0 |
out of range |
||
|
1 |
QPSK |
78 |
0.1523 |
|
2 |
QPSK |
193 |
0.3770 |
|
3 |
QPSK |
449 |
0.8770 |
|
4 |
16QAM |
378 |
1.4766 |
|
5 |
16QAM |
616 |
2.4063 |
|
6 |
64QAM |
567 |
3.3223 |
|
7 |
64QAM |
666 |
3.9023 |
|
8 |
64QAM |
772 |
4.5234 |
|
9 |
64QAM |
873 |
5.1152 |
|
10 |
256QAM |
711 |
5.5547 |
|
11 |
256QAM |
797 |
6.2266 |
|
12 |
256QAM |
885 |
6.9141 |
|
13 |
256QAM |
948 |
7.4063 |
|
14 |
1024QAM |
853 |
8.3301 |
|
15 |
1024QAM |
948 |
9.2578 |
Table 7.2.3-5: 4-bit CQI Table 5
|
CQI index |
modulation |
code rate x 1024 |
efficiency |
|
0 |
out of range |
||
|
1 |
QPSK |
40 |
0.0781 |
|
2 |
QPSK |
78 |
0.1523 |
|
3 |
QPSK |
120 |
0.2344 |
|
4 |
QPSK |
193 |
0.3770 |
|
5 |
QPSK |
308 |
0.6016 |
|
6 |
QPSK |
449 |
0.8770 |
|
7 |
QPSK |
602 |
1.1758 |
|
8 |
16QAM |
378 |
1.4766 |
|
9 |
16QAM |
490 |
1.9141 |
|
10 |
16QAM |
616 |
2.4063 |
|
11 |
64QAM |
466 |
2.7305 |
|
12 |
64QAM |
567 |
3.3223 |
|
13 |
64QAM |
666 |
3.9023 |
|
14 |
64QAM |
772 |
4.5234 |
|
15 |
64QAM |
873 |
5.1152 |
Table 7.2.3-6: 4-bit CQI Table 6
|
CQI index |
modulation |
code rate x 1024 |
repetition |
|
0 |
out of range |
||
|
1 |
QPSK |
56 |
32 |
|
2 |
QPSK |
207 |
16 |
|
3 |
QPSK |
266 |
4 |
|
4 |
QPSK |
195 |
2 |
|
5 |
QPSK |
142 |
1 |
|
6 |
QPSK |
266 |
1 |
|
7 |
QPSK |
453 |
1 |
|
8 |
QPSK |
637 |
1 |
|
9 |
16QAM |
423 |
1 |
|
10 |
16QAM |
557 |
1 |
|
11 |
16QAM |
696 |
1 |
|
12 |
16QAM |
845 |
1 |
|
13 |
64QAM |
651 |
1 |
|
14 |
64QAM |
780 |
1 |
|
15 |
64QAM |
888 |
1 |