why suggestion for lte rsrp is -105dbm

8/10/2019 Why Suggestion for LTE RSRP is -105dBm

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2014-12-20 1, 3

Why suggestion for LTE RSRP is -105dBm?

LTE coverage standard is measured by RS pilot channel power RSRP (Reference

Signal Received Power), we can get the indoor edge field strength of RS based on the

RXsensitivity:RSRP -174 + 10lg(15000) + NF + SINR + IoT + SM, (NF :

Noise figure; SINR: Signal to interference plus noise ratio; IOT: Interference over

thermal; SM: slow fading margin ) According to the requirements of edge rate, SINR

is based on the 10RB occupied by one user, IoT is supposed to be 7dB, NF is equal to

7dB, the slow fading margin SM value is depende on coverage probability and

standard variance of SM. Based on the current research: in case of 95% indoor

coverage area, the SM standard error criterion values of different scenarios as follows:

In this paper, the slow fading margin is defined as 7dB, then the requriements of the

RSRP are as follows:

No. Edge rate Edge SINR Edge RSRP

1 2 Mbps 6 dB -105 dBm

2 1 Mbps 4 dB -110 dBm

3 0.5 Mbps 0 dB -115 dBm

For indoor coverage, the -105dBm edge strength can satisfy the severice requirement.

In LTE, the RS is defined as pilot signal, the RSRP is a sub-carrier power, for 20MHz

scenarioshadow fading standard

variance

shadow fading

margin(dB)

Recreation Ground

7

8.6

Office Building

6

7

Hotel

7

8.6

Supermarket

6

7

Airport/

exhibition hall

6

7

Parking

6

4
http://www.iciba.com/sensitivity/http://www.iciba.com/sensitivity/


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2014-12-20 2, 3

carrier band , there are 1200 sub-carrier , if the edge RSRP is -85dBm, the coverage radius is

15m, the edge total power=-85dBm+10log(1200)=-54.2dBm, then we can calculate the output

power of antenna is about 30dBm by ITU-R P.1238propagation, when the indoor antenna

output power is more than 15dBm, it will affect public security according to the ICNIRP

(International Commission on Non-ionizing Radiation Protection) standard.

ITU-R P.1238 indoor propagation model .

XdB28loglog20 nfLdNfL

NDistance loss coefficient

fFrequency (unit: MHz)

dDistance between a mobile station and a transmitter (unit:

m) m1d

nfL Floor penetration loss coefficient

XSlow fading margin: Its value is related to the coverage

probability requirement and the indoor slow fading standard variance. It

has been considered in edge coverage criterion.

For example, N=20, f=2600MHz, Lf(n)=20dB, X= 7dB, the total output power of antenna is

10dBm, the output RSRP of antenna=10-10log1200=-20.8dBm, If the the edge RSRP is -85dBm,

then it can calculate the coverage raduis d=2.21m, so the distance between two antennas is

2*d=4.41m, if the edge RSRP is -85dBm, the cost of deployment and implementation of the


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2014-12-20 3, 3

project can not be realized.

Comparing GSM900, UMTS2100 and LTE 2600, if LTE RSPR is -85dBm, the GSM900 BCCH

coverage level must be up to -40.7dBm, and UMTS2100 CPICH level must be up to -52dBm. It is

difficult for GSM900 and UMTS2100 to achieve this coverage requirement

Cost of deployment and implementation of the project can not be realized

According to the HUAWEI commerical and trial network experience, RS power of single RE is

difficult to meet the -85dBm requirement. So Huawei suggest the edge RSRP is -105dBm.

System GSM UMTS LTE

Frequency(MHz) 900 2100 2600

RRU output pilot

power(dBm)

46 33 15.2

why suggestion for lte rsrp is -105dbm

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