RS SINR/PDSCH SINR

[gunpowder]

Dear all,

is LTE CQI calculated based on RS SINR or PDSCH SINR (scheduler will depend on which SINR)
and why always PDSCH SINR is way better than RS SINR values (from DT measurements)

Thanks,

[DANORM]

As i know RS SINR should be better than PDSCH SINR due to power utilization is less on RS and impact on SINR from neighbor cells should be less.


Dear all,

is LTE CQI calculated based on RS SINR or PDSCH SINR (scheduler will depend on which SINR)
and why always PDSCH SINR is way better than RS SINR values (from DT measurements)

Thanks,

[gunpowder]

all my logs (E// and Huawei) show that RS SINR is lower Than PDSCH SINR [[Tems Investigation and Discovery]]

[DANORM]

Have you tried prediction using your power configurations?

[gunpowder]

currently i'm not using CRSGain or RS Power boosting/deboosting
so RS power shoud be equal to PDSCH Power == Pa

[linhhy]

This result comes from low load network. With good PCI planning, synchronization network, we could say network load for RS is 20-30% because the interference only comes from neighbors in different sites. I believe that PDSCH load even lower than 20%.
In high load network, PDSCH CINR will worst than RS CINR.


Dear all,

is LTE CQI calculated based on RS SINR or PDSCH SINR (scheduler will depend on which SINR)
and why always PDSCH SINR is way better than RS SINR values (from DT measurements)

Thanks,

[DANORM]

even totally no load on the cells, the simulations in Atoll shows that everytime RS SINR is better. Just better to see other guys opinions and practical experience

[gunpowder]

can anyone share their network experience to confirm this issue :)

[linhhy]

even totally no load on the cells, the simulations in Atoll shows that everytime RS SINR is better. Just better to see other guys opinions and practical experience

It's not everytime actually. Figure below show PDSCH CINR is better.
4031940320

[linhhy]

can anyone share their network experience to confirm this issue :)

It's not easy because not many handsets can capture PDSCH CINR today

[DANORM]

Can you explain why is PDSCH CINR better and whats the power configurations you have including total output power and RS


It's not everytime actually. Figure below show PDSCH CINR is better.
4031940320

[gunpowder]

i know it is a basic question :) but CQI will be calcualated on which SINR

[khurrambilal01]

Actually LTE Scheduler is generally interference based scheduler which doesn't assign the worst PDSCHs. So most of the times you will be assigned cleaner subcarriers.
On the other hand RS is transmitted on same frequencies for generally all NW cells and PDSCH on the other hand is not always being used for all neighbor cells. Hence PDSCH SINR is better compared with RS SINR... UE reports Sub-Band CQI (If activated) as well as Wideband CQI...

[marcengo]

DL-RS....filling................................................

i know it is a basic question :) but CQI will be calcualated on which SINR

[DANORM]

CQI is measured on Cell Specific RS and in Rel-10 introduced CSI-RS iChannel State Information Reference Signal (which is different location)


i know it is a basic question :) but CQI will be calcualated on which SINR

[linhhy]

Can you explain why is PDSCH CINR better and whats the power configurations you have including total output power and RS

It's normal power configuration:
- Downlink transmit power calculation: RS EPRE: 0-Calculated.
- No power offset between RS and PDSCH channel.
- DL load: 50%.
- Not yet PCI planning.

[DANORM]

I guess if DL load is 50%, PDSCH SINR should be worse


It's normal power configuration:
- Downlink transmit power calculation: RS EPRE: 0-Calculated.
- No power offset between RS and PDSCH channel.
- DL load: 50%.
- Not yet PCI planning.

[linhhy]

I missed one more important parameter: Multi-antenna interference calculation Method: 0-indipendent of the number of antennas.. With other setting I guess PDSCH SINR (50% load, 2Tx) should be same as RS CINR in case not yet PCI planning.


I guess if DL load is 50%, PDSCH SINR should be worse

[hieuphong]

Hi Guys,

I also saw that Sc RS CINR (Scanner) is worse than RS SINR (Dedicated_DL). We used PC Tel to test Scanner and Note 4 for Dedicated). Who can explain that for me?
One thing: Why is maximum the Sc RS CINR value of Scanner is 40, the maximum the SINR value of UE is 30?

[crisnspro]

I know the scanner, UE maybe is different

[Weiland86]

Just wondering, Why RS SINR is affected by the load of the cell, if RS power is not affected by the load also the power used in that secific period of time should be the same does not amttter the number of UEs allocated to the cell.
If someone can explain me this and also what is the better SINR measurement to take in consideration.

Thanks in advanced.

[hassan.attique]

RS SINR will be impact due to interference from the neighboring sites. SINR formula in denominator has interference from neighbor sites. So if load increased in neighbor sites PDSCH will be used which will cause interference.


Just wondering, Why RS SINR is affected by the load of the cell, if RS power is not affected by the load also the power used in that secific period of time should be the same does not amttter the number of UEs allocated to the cell.
If someone can explain me this and also what is the better SINR measurement to take in consideration.

Thanks in advanced.