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SINR vs. RSRP and RSRQ For field measurements Only for internal use; Confidential document

Rsrp vs Rsrq vs Sinr

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Rsrp vs Rsrq vs Sinr

Text of Rsrp vs Rsrq vs Sinr

  • SINR vs. RSRP and RSRQFor field measurements

    Only for internal use; Confidential document

    * Meritech.co.ltdFor internal use only

    RSRPRSRP is the power of a single resource element. UE measures the power of multiple resource elements used to transfer the reference signal but then takes an average of them rather than summing them.

    Definition: Reference signal received power (RSRP), is defined as the linear average over the power contributions (in [W]) of the resource elements that carry cell-specific reference signals within the considered measurement frequency bandwidth.For RSRP determination the cell-specific reference signals R0 according TS 36.211 [3] shall be used. If the UE can reliably detect that R1 is available it may use R1 in addition to R0 to determine RSRP.If receiver diversity is in use by the UE, the reported value shall not be lower than the corresponding RSRP of any of the individual diversity branches.

    * Meritech.co.ltdFor internal use only

    RSRP reporting rangeFrom -44 dBm to -133 dBm

    Document explaining RSRP reporting range details:

    1

    TSG-RAN Working Group 4 (Radio) meeting #46bis R4-080625

    Shenzhen, China, 31 March 4 April, 2008

    Source:Ericsson

    Title:Reporting Range of RSRP

    Agenda item:5.2.7.7

    Document for:Approval

    1. Background

    The RSRP measurement requirements are being defined in TS 36.133 [1]. The measurement quantity will be reported for up to certain range. This paper derives the reporting range of RSRP and some thoughts also on the range of RSRP over which the guaranteed accuracy requirements should be specified.

    2. Derivation of Reporting Range

    The RSRP shall be reported between certain minimum and maximum values. They are derived in the following sections:

    2.1 Minimum Reportable Level

    Let RSRPmin be the lowest RSRP that can be measured by the UE. Therefore UE should be able to report RSRP up to this level (RSRPmin). The level is derived as follows:

    Let noise power (PN) within bandwidth B at a point where the measurement is carried out is expressed as:

    (1)

    Where:

    NF: Noise figure = 7 dB

    K: Boltzmann constant = 1.380 6504 x 1023 JK-1T: Temperature = 290 0K

    B: Bandwidth of one sub-carrier = 15 KHz; RSRP is measured on resource element level (i.e. resource element containing the reference symbols) and the reported quantity is the average of all contributions.

    Using the above assumptions: PN = -125.2 dBm. RSRP is the received power of reference symbols measured by the UE at a certain geometry factor. Therefore RSRP can be transformed from PN according to the following expression:

    (2)

    Where

    is the lowest geometry factor for which RSRP could be reported and is assumed to be -8 dB; note the RSRP measurement accuracy is being defined for geometry factor up to -6 dB.

    Using transformation according to (2): RSRPmin = -133.2 dBm

    Based on the above analysis the RSRP can be reported up to the lowest level of -133 dBm.

    From network perspective it is beneficial to have large RSRP reportable value. This will enable network to keep the UE in a cell especially in idle mode as long as it can detect the serving cell.

    2.2 Maximum Reportable Level

    The maximum input level for the UE is -25 dBm for all bands [4]. This corresponds to the total received power (or). But RSRP is measured only on the reference symbols, which constitute only fraction of total power. Therefore the maximum RSRP should be the fraction of maximum input level. Furthermore RSRP is defined as the received power per resource element containing the reference symbols. Therefore the maximum RSRP for shortest measurement bandwidth (6 RB) can be derived as follows:

    Maximum RSRP = Maximum input level + 10log10(1/72)

    Maximum RSRP = -25 - 18.57 [dBm] ( -44 dBm

    Therefore maximum reportable RSRP should be: -44 dBm

    2.3 Range with guaranteed measurement accuracy

    The RSRP accuracy becomes worse at lower geometry factors when reported RSRP level is also very low. An implementation margin is to be added to the lowest reportable RSRP to obtain the corresponding RSRP with guaranteed accuracy requirements. This is typically dependent upon the frequency band as specified for RSCP in WCDMA [3]; e.g. guaranteed accuracy up to RSCP = -114 dBm for band I (2 GHz) whereas the reporting range up to -120 dBm (i.e. margin = 6 dB for band I).

    3 Proposal

    Based on the analysis and arguments provided in this document the RSRP reporting range is suggested to be specified between -44 dBm to -133 dBm. A text proposal is provide for a new section 9.1.x (9.1.4) in TS 36.133 [2].

    If the proposal is acceptable then we suggest LS is sent to RAN2 so that corresponding RRC signalling is defined in the RRC specification (TS 36.331).

    4 References

    [1] 3GPP TS 36.133, Evolved Universal Terrestrial Radio Access (E-UTRA); Requirements for support of radio resource management.

    [2] 3GPP TS 36.214, Evolved Universal Terrestrial Radio Access (E-UTRA); Physical layer; Measurements.

    [3] 3GPP TS 25.133, Requirements for support of radio resource management (FDD).

    [4] 3GPP TS 36.101, Evolved Universal Terrestrial Radio Access (E-UTRA); User Equipment (UE) radio transmission and reception.

    ----------------------START OF TEXT PROPOSAL --------------------------

    9.1.2Intra-frequency RSRP Accuracy Requirements

    9.1.2.1Absolute RSRP Accuracy

    The absolute accuracy of RSRP is defined as the RSRP measured from a cell on the same frequency as that of the serving cell.

    The accuracy requirements in table 9.1.2.1-1 are valid under the following conditions:

    Cell specific reference signals are transmitted either from one, two or four antenna ports.

    RSRP|dBm( [TBD] dBm for Bands [TBD]

    Table 9.1.2.1-1: RSRP Intra frequency absolute accuracy

    Parameter

    Unit

    Accuracy [dB]

    Conditions

    Normal condition

    Extreme condition

    Bands

    Io

    RSRP for or/Ioc ( -6 dB

    dBm

    TBD

    TBD

    TBD

    9.1.2.2Relative Accuracy of RSRP

    The relative accuracy of RSRP is defined as the RSRP measured from one cell compared to the RSRP measured from another cell on the same frequency.

    The accuracy requirements in table 9.1.2.2-1 are valid under the following conditions:

    Cell specific reference signals are transmitted either from one, two or four antenna ports.

    RSRP1,2|dBm( [TBD] dBm for Bands [TBD]

    Table 9.1.2.2-1: RSRP Intra frequency relative accuracy

    Parameter

    Unit

    Accuracy [dB]

    Conditions

    Normal condition

    Extreme condition

    Bands

    Io

    RSRP for or/Ioc > -3 dB

    dBm

    ( [2]

    TBD

    TBD

    RSRP for or/Ioc -6 dB

    dBm

    ( [3]

    TBD

    TBD

    9.1.3Inter-frequency RSRP Accuracy Requirements

    9.1.xRSRP Measurement Report Mapping

    The reporting range of RSRP is defined from -133 dBm to -44 dBm with 1 dB resolution.

    The mapping of measured quantity is defined in table 9.1.x-1. The range in the signalling may be larger than the guaranteed accuracy range.

    Table 9.1.x-1: RSRP measurement report mapping

    Reported value

    Measured quantity value

    Unit

    RSRP_00

    RSRP ( -133

    dBm

    RSRP_01

    -133 ( RSRP < -132

    dBm

    RSRP_02

    -132 ( RSRP < -131

    dBm

    RSRP_88

    -46 ( RSRP < -45

    dBm

    RSRP_89

    -45 ( RSRP < -44

    dBm

    RSRP_90

    -44 ( RSRP

    dBm

    ------------------------END OF TEXT PROPOSAL-----------------------

    3GPP

    _1267700995.unknown

    _1267720592.unknown

    _1267720606.unknown

    _1263646248.unknown

    * Meritech.co.ltdFor internal use only

    RSRQRSRQ = RSRP / (RSSI/N)N is the number of resource blocks over which the RSSI is measuredRSSI is wide band power, including intracell power

    Definition:Reference Signal Received Quality (RSRQ) is defined as the ratio NRSRP/(E-UTRA carrier RSSI), where N is the number of RBs of the E-UTRA carrier RSSI measurement bandwidth. The measurements in the numerator and denominator shall be made over the same set of resource blocks.E-UTRA Carrier Received Signal Strength Indicator (RSSI), comprises the linear average of the total received power (in [W]) observed only in OFDM symbols containing reference symbols for antenna port 0, in the measurement bandwidth, over N number of resource blocks by the UE from all sources, including co-channel serving and non-serving cells, adjacent channel interference, thermal noise etc. If receiver diversity is in use by the UE, the reported value shall not be lower than the corresponding RSRQ of any of the individual diversity branches.

    * Meritech.co.ltdFor internal use only

    RSRQ reporting rangeImpact of intra cell power to RSRQ:Example for noise limited case (no interference):If all resource elements are active and are transmitted with equal power thenRSRQ = N / 12N = -10.8 dB (because RSRP is measured over 1 resource element and RSSI per resource block is measured over 12 resource elements)

    When there is no traffic, and assuming only the reference symbols are transmitted (there are 2 of them within the same symbol of a resource block) then the RSSI is generated by only the 2 reference symbols so the result becomes;RSRQ = N / 2N = -3 dB

    Document explaining RSRQ reporting range details:

    2

    TSG-RAN Working Group 4 (Radio) meeting #47bis R4-081419

    Munich, Germany, June 16 20, 2008

    Source:Ericsson

    Title:RSRQ Reporting Range

    Agenda item:6.1.7.7

    Document for:Approval

    1. Background

    The RSRQ measurement requirements are being defined in TS 36.133 [1]. The measurement quantity will be reported for up to certain range. This paper analyzes the reporting range of RSRQ and based on this analyzes a text proposal on the reporting range is provided.

    2. Derivation of Reporting Range

    In TS 36.214 RSRQ is defined as follows:

    Reference Signal Received Quality (RSRQ) is defined as the ratio NRSRP/(E-UTRA carrier RSSI), where N is the number of RBs of the E-UTRA carrier RSSI measurement bandwidth. The measurements in the numerator and denominator shall be made over the same set of resource blocks.

    The RSRQ shall be reported between certain minimum and maximum values. They are derived in the following sections:

    2.1 Minimum Reportable Level

    The minimum RSRQ is typically observed at lowest geometry factor up to which the RSRQ should be measured and reported.

    Let us assume that RSRQ is reportable up to:

    = -8 dB.

    Let us also assume that received total power (

    ) from the cell whose RSRQ is measured is 1, i.e:

    = 1; on linear scale, then total received power from other cells and noise (

    ) = 6.3; on linear scale

    RSSI includes power and noise from all sources therefore:

    RSSI =

    = 1 + 6.3 = 7.3; (1)

    Where RSSI is expressed in linear scale

    Assuming

    = 1 then RSRP on the linear scale can be expressed as:

    RSRP = 1/(12N) (2)

    Where N is the number of resource blocks over which RSSI is measured. Note that RSRP is expressed on resource element level and each resource block comprises of 12 sub-carriers.

    By combining (1) and (2) RSRQ in linear scale can be written as:

    RSRQ = N*1/(12N)/7.3 (3)

    RSRQ = 1/87.6 ( 0.0114 (linear scale) ( -19.5 dB (4)

    Thus the minimum RSRQ (RSRQmin) should be down to -19.5 dB.

    2.2 Maximum Reportable Level

    The maximum RSRQ is derived assuming transmission from an empty cell, which transmits only reference symbols and other necessary control information e.g. SCH, PCFICH and BCH. To derive maximum RSRQ let us consider the contributions from reference symbols.

    Then main contributor to RSSI will be the power of the reference symbols. Let us express the RSSI in terms of RSRP as follows:

    RSSI = RSRP x 2N (5)

    Note again that RSRP is expressed on resource element level and there are 2 resource elements per RB, which contains RS.

    Using (5) RSRQ can be written as:

    RSRQ = N x RSRP/ (RSRPx2N) (6)

    RSRQmin = -3 dB (7)

    Thus the largest RSRQ reportable value should be -3 dB.

    In the above analysis the main contributor to RSSI is considered to be the power of the reference symbols. Hence in case of boosting of the reference symbol power both RSRP and RSSI shall be boosted with equal amount thus keeping RSRQ at constant level.

    3. Summary of Proposal

    The above analysis reveals that RSRQ should be reported between -19.5 to -3 dB. It is further suggested that RSRQ is reported with a resolution of 0.5 dB. The reported RSRQ values are numbered from 00 to 46 to cover all RSRQ ranges between -19.5 to -3 dB; this leads to a total number of 47 reportable values.

    A text proposal is provide for a new section 9.1.x (9.1.7) in TS 36.133 [1].

    If the proposal is acceptable then we suggest LS is sent to RAN2 so that corresponding RRC signalling is defined in the RRC specification TS 36.331 [2].

    3 References

    [1] 3GPP TS 36.133, Evolved Universal Terrestrial Radio Access (E-UTRA); Requirements for support of radio resource management.

    [2] 3GPP TS 36.331, Evolved Universal Terrestrial Radio Access (E-UTRA); Radio Resource Control (RRC); Protocol specification.

    ----------------------START OF TEXT PROPOSAL --------------------------

    9.1.5Intra-frequency RSRQ Accuracy Requirements

    9.1.5.1Absolute RSRQ Accuracy

    The absolute accuracy of RSRQ is defined as the RSRQ measured from a cell on the same frequency as that of the serving cell.

    The accuracy requirements in table 9.1.5.1-1 are valid under the following conditions:

    Cell specific reference signals are transmitted either from one, two or four antenna ports.

    RSRP|dBm( [-127] dBm for Bands [I]

    Table 9.1.5.1-1: RSRQ Intra frequency absolute accuracy

    Parameter

    Unit

    Accuracy [dB]

    Conditions1

    Normal condition

    Extreme condition

    Bands I,..

    Bands

    Io

    Io

    RSRQ when RSRP s/Iot > -3 dB

    dBm

    ( [2.5]

    ( [4]

    [-121dBm/15kHz -50dBm]

    TBD

    RSRQ when RSRP s/Iot -6 dB

    dBm

    ( [3.5]

    ( [4]

    [-121dBm/15kHz -50dBm]

    TBD

    Note 1. Io is assumed to have constant EPRE across the bandwidth.

    [Editors note: Definition of s and Iot should be added to Symbols]

    9.1.6Inter-frequency RSRQ Accuracy Requirements

    9.1.6.1Absolute RSRQ Accuracy

    The absolute accuracy of RSRQ is defined as the RSRQ measured from a cell that has different carrier frequency from the serving cell.

    The accuracy requirements in table 9.1.6.1-1 are valid under the following conditions:

    Cell specific reference signals are transmitted either from one, two or four antenna ports.

    RSRP|dBm( [-127] dBm for Bands [I]

    Table 9.1.6.1-1: RSRQ Inter frequency absolute accuracy

    Parameter

    Unit

    Accuracy [dB]

    Conditions1

    Normal condition

    Extreme condition

    Bands I,..

    Bands

    Io

    Io

    RSRQ when RSRP s/Iot > -3 dB

    dBm

    ( [2.5]

    ( [4]

    [-121dBm/15kHz -50dBm]

    TBD

    RSRQ when RSRP s/Iot -6 dB

    dBm

    ( [3.5]

    ( [4]

    [-121dBm/15kHz -50dBm]

    TBD

    Note 1. Io is assumed to have constant EPRE across the bandwidth.

    [Editors note: Definition of s and Iot should be added to Symbols]

    9.1.6.2Relative Accuracy of RSRQ

    The relative accuracy of RSRQ in inter frequency case is defined as the RSRQ measured from one cell compared to the RSRQ measured from another cell on a different frequency.

    The accuracy requirements in table 9.1.6.2-1 are valid under the following conditions:

    Cell specific reference signals are transmitted either from one, two or four antenna ports.

    RSRP1|dBm ( [-127] dBm if RSRP1 is on Band [I],

    RSRP2|dBm ( [-127] dBm if RSRP2 is on Bands [I],

    | Channel 1_Io Channel 2_Io | ( [20] dB

    Table 9.1.6.2-1: RSRQ Inter frequency relative accuracy

    Parameter

    Unit

    Accuracy [dB]

    Conditions1

    Normal condition

    Extreme condition

    Bands I,..

    Bands

    Io

    Io

    RSRQ when RSRP s/Iot > -3 dB

    dBm

    ( [3]

    ( [4]

    [-121dBm/15kHz -50dBm]

    TBD

    RSRQ when RSRP s/Iot -6 dB

    dBm

    ( [4]

    ( [4]

    [-121dBm/15kHz -50dBm]

    TBD

    Note 1. Io is assumed to have constant EPRE across the bandwidth.

    [Editors note: Definition of s and Iot should be added to Symbols]

    9.1.xRSRQ Measurement Report Mapping

    The reporting range of RSRQ is defined from -19.5 dB to -3 with 0.5 dB resolution.

    The mapping of measured quantity is defined in table 9.1.x-1. The range in the signalling may be larger than the guaranteed accuracy range.

    Table 9.1.x-1: RSRQ measurement report mapping

    Reported value

    Measured quantity value

    Unit

    RSRQ_00

    RSRQ ( -19.5

    dB

    RSRQ_01

    -19.5 ( RSRQ < -19

    dB

    RSRQ_02

    -19 ( RSRQ < -18.5

    dB

    RSRQ_43

    -4 ( RSRQ < -3.5

    dB

    RSRQ_44

    -3.5 ( RSRQ < -3

    dB

    RSRQ_46

    -3 ( RSRQ

    dB

    ------------------------END OF TEXT PROPOSAL-----------------------

    3GPP

    _1270555760.unknown

    _1274265025.unknown

    _1274265064.unknown

    _1274265185.unknown

    _1274264991.unknown

    _1267700995.unknown

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    Field measurement parametersTerminals are measuring from service cell:RSRPRSRQScanners are measuring from all decoded cells:RSRPRSRQRSSI => Received Signal Strength Indicator(Wideband channel power)P-SCH and S-SCH RSSIReference signal SINR

    Mapping from RSRP/RSRQ to SINR needed

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    SINRRSRP to SNR mappingOpen question: does RSRP include noise power from measured bandwidth?Impact on RSRP -> SNR mapping with low RSRP valuesRSRP is measured for a single subcarriernoisepower_for_15KHz= -125.2dBmNoise figure = 7 dBTemperature = 290 KCase 1: RSRP doesnt contain noise power

    Case 2: RSRP contains noise power

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    SNRComparing two equations Case 1

    Case 2

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    RSRQ to SINR mappingRSRQ depends on own cell traffic load, but SINR doesnt depend on own cell load.Used Resource Elements per Resource Block (RE/RB) in serving cell is an input parameter for RSRQ -> SINR mappingTwo cases:Case 1: RSRP doesnt contain noise powerCase2: RSRP contains noise power

    Case 1:Case 2:

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    RSRQ to SINR mappingCase 1 equation used, as it is simpler

    x=RE/RB

    2RE/RB equals to empty cell. Only Reference Signal power is considered from serving cell.12RE/RB equals to fully loaded serving cell. All resource elements are carrying data.

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    RSRQ to SINR mapping Lab measurements matches well the calculated resultsMeasured with Agilent scannerRSRPRSRQReference signal SINRCable connection between BTS and scannerAttenuator used to reduce signal levelNo traffic = only control chs and reference signalsFull traffic load = data send in each RB

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    Coverage criteria for field measurementsCoverage criteria for field measurement can be estimated with link budget toolDepends on UL and DL parametersTypical coverage requirement is that 95% of the measurement samples is fulfilling the criteria. (depends on operators coverage requirements)

    Example, outdoor coverage:Throughput requirement 500/64kbps (DL/UL)20W BTS Tx powerIf DL only considered:-SINR requirement -6dB=> RSRQ>-16.9dB, empty serving cell RSRQ>-17.7dB, fully loaded serving cell RSRP>-130dBm (1dB interference assumed)If DL and UL considered-DL SINR requirement -3dB=> RSRQ>-14.1dB, empty serving cell RSRQ>-15.5dB, fully loaded serving cell RSRP>-127dBm (1dB interference assumed)

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    Parameters are reported at one second interval.XCAL + Samsung reported parametersSamsung + XCAL, the most used drive test combination at the moment in trials and FiVe.

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    Scanner measurement informationPCTelMeasuring both RS SINR and SCH SINRWide band RSSI measurements and spectrum scanning supported

    R&SMeasuring only SCH SINRNo support for wide band RSSI measurements and spectrum scanning Measuring only from Sync channel bandwidth (1.4MHz). Also RSRP and RSRQ measured only from that bw.

    JDSU E6474AMeasuring only RS SINRDifficult post processing format (in Excel export)Wide band RSSI measurements and spectrum scanning supported

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    How can we calculate CQI from SINR?Basically, we can calculate as CQI= SINR * 0.51 +5.3- Sample of MIMO Switching