106478603-rsrp-vs-rsrq-vs-sinr.pdf

1 © Nokia Siemens Networks Presentation / Author / Date

I insert classification level

SINR vs. RSRP and RSRQ For field measurements

Jyri Lamminmäki

22.9.2009


Soc Classification level

RSRP

•RSRP 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.



RSRP reporting range

•From -44 dBm to -133 dBm

•Document explaining RSRP reporting range details:



RSRQ

•RSRQ = RSRP / (RSSI/N)

– N is the number of resource blocks over which the RSSI is measured

– RSSI is wide band power, including intracell power

Definition:

Reference Signal Received Quality (RSRQ) is defined as the ratio N×RSRP/(E-UTRA carrier RSSI), where N is the number of RB’s 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.



RSRQ reporting range

•Impact 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 then

RSRQ = 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:



SINR definition

• SINR is the reference value used in the system simulation

• SINR can be defined:

1. Wide band SINR

2. SINR for a specific subcarrier (or for a specific RE)

• Straight forward SINR measurement is difficult on field

– Own cell power should be separated from other cell power.



Field measurement parameters

•Terminals are measuring from service cell:

– RSRP

– RSRQ

• Scanners are measuring from all decoded cells:

– RSRP

– RSRQ

– Wideband channel power

– P-SCH and S-SCH RSSI

– Reference signal SINR

• Mapping from RSRP/RSRQ to SINR needed



SNR

• RSRP to SNR mapping

• Open question: does RSRP include noise power from measured bandwidth?

– Impact on RSRP -> SNR mapping with low RSRP values

• RSRP is measured for a single subcarrier

– noisepower_for_15KHz= -125.2dBm

▪ Noise figure = 7 dB

▪ Temperature = 290 K

• Case 1: RSRP doesn’t contain noise power

• Case 2: RSRP contains noise power

powernoiseKHzP

P

PRSRPSNR

REn

REn

REn

__15_

_

_

powernoiseKHzP

P

RSRPSNR

REn

REn

__15_

_



SNR

•Comparing two equations

– Case 1

– Case 2

powernoiseKHzP

P

PRSRPSNR

REn

REn

REn

__15_

_

_

Case 1 Case 2

RSRP linear RSRP(dBm) SNR(dB) SNR(dB)

1.0E-08 -50 75.21 75.21

3.2E-09 -55 70.21 70.21

1.0E-09 -60 65.21 65.21

3.2E-10 -65 60.21 60.21

1.0E-10 -70 55.21 55.21

3.2E-11 -75 50.21 50.21

1.0E-11 -80 45.21 45.21

3.2E-12 -85 40.21 40.21

1.0E-12 -90 35.21 35.21

3.2E-13 -95 30.21 30.21

1.0E-13 -100 25.21 25.20

3.2E-14 -105 20.21 20.17

1.0E-14 -110 15.21 15.08

3.2E-15 -115 10.21 9.78

1.0E-15 -120 5.21 3.66

3.2E-16 -125 0.21 -12.96

1.0E-16 -130 -4.79 #NUM!

3.2E-17 -135 -9.79 #NUM!

powernoiseKHzP

P

RSRPSNR

REn

REn

__15_

_



RSRQ to SINR mapping

• RSRQ depends on own cell traffic load, but SINR doesn’t depend on own cell load. – Used Resource Elements per Resource Block (RE/RB) in serving cell is an input

parameter for RSRQ -> SINR mapping

• Two cases: – Case 1: RSRP doesn’t contain noise power

– Case2: RSRP contains noise power

RSSI

RSRPNRSRQ

PxNRSRPPRSSI

RBsN

usedRBREx

xNPP

PP

PNRSRPSINR

Nxni

REnxNn

Nni

Nn

*

*

#

_/

12*

)12_(

__

12_

12_

xNn

Nn

NnNxn

Nn

PxNRSRPRSRQ

RSRPN

PNRSRP

PPxNRSRPRSRQ

RSRPN

PNRSRPSINR

_

12_

12_)12_(

12_

**

12*

**

12*

RSSI

RSRPNRSRQ

PxNRSRPPRSSI

RBsN

usedRBREx

xNPP

PP

NRSRPSINR

Nni

REnxNn

Nni

*

*

#

_/

12*

12_

__

12_

xRSRQ

xNRSRPRSRQ

RSRPN

NRSRPSINR

1

12

**

12*

Case 1: Case 2:




•Case 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.

xRSRQ

SINR

1

12

RSRP vs. SNR

-15.00

-10.00

-5.00

0.00

5.00

10.00

15.00

20.00

25.00

30.00

35.00

40.00

-135 -130 -125 -120 -115 -110 -105 -100 -95 -90 -85 -80 -75 -70

RSRP (dBm)

SN

R (

dB

)

SNR

RSRQ vs SINR

-10.00

-5.00

0.00

5.00

10.00

15.00

20.00

25.00

30.00

-20 -19 -18 -17 -16 -15 -14 -13 -12 -11 -10 -9 -8 -7 -6 -5 -4 -3

RSRQ (dB)

SIN

R (

dB

)

2 RE/RB

4 RE/RB

6 RE/RB

8 RE/RB

10 RE/RB

12 RE/RB




•Lab measurements matches well the calculated results

•Measured with Agilent scanner

– RSRP

– RSRQ

– Reference signal SINR

•Cable connection between BTS and scanner

– Attenuator used to reduce signal level

– No traffic = only control chs and reference signals

– Full traffic load = data send in each RB

SINR vs. RSRQ

-10

-5

0

5

10

15

20

25

30

35

-20 -19 -18 -17 -16 -15 -14 -13 -12 -11 -10 -9 -8 -7 -6 -5 -4 -3 -2 -1 0

RSRQ

SIN

R

Measured - full traffic Caculated - no traffic Calculated - full traffic load Measured - no traffic

SNR vs. RSRP

-15

-10

-5

0

5

10

15

20

25

30

35

40

-140 -135 -130 -125 -120 -115 -110 -105 -100 -95 -90 -85 -80

RSRP

SN

R

Measured-full traffic

Calculated

Measured - no traffic



Coverage criteria for field measurements

•Coverage criteria for field measurement can be estimated with link budget tool – Depends on UL and DL parameters

•Typical 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 power

If 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)

Channel Model

Antenna Configuration 1Tx-2Rx 1Tx-2Rx

FDPS Type Round Robin -

Users in Frequency Domain per TTI 2 10

FDPS Gain (dB) 0.00 -

HARQ Gain (dB) 4.58 5.45

Minimum Required SINR (dB) -1.69 3.76

Coding Rate Offset (dB) 0.20 0.34

Required SINR at Cell Edge (dB) -6.06 -1.35

Maximum SINR at Cell Edge (dB) -0.03 -

Neighbour Cell Load 50% 50%

Method for Interference Margin User Defined User Defined

Interference Margin [Formula/Simulation] (dB) not selected not selected

Interference Margin [User Defined] (dB) 1.00 1.00

Number of Received Subcarriers (dB) 27.8 10.8

Thermal Noise Density (dBm/Hz)

Subcarrier Bandwidth (kHz)

Noise Power per Subcarrier (dBm)Receiver Sensitivity (dBm) -103.45 -120.53

Maximum Allowable Path Loss (dB)

(clutter not considered) 162.96 160.03

-174

15

-132.17

Enhanced Pedestrian A 5 Hz

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