1. Interference in DVB-T reception resulting from LTE base stations
Ivan Pasković, dipl.ing.el.
04. October 2011.

2. Introduction Background Interference concerns
Preliminary field measurements
Conclusions
HAKOM Open
20/11/2018

3. Migration to DVB-T and digital dividend
Migration to DVB-T finished in 2010.
Succesfull analog TV switch-off in 2010.
Digital dividend:
Figure 1*: Preferred harmonised frequency arrangement plan
*(taken from CEPT report 30. ref 1)
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20/11/2018

4. Interference concerns
Figure 2: Interference to existing DVB-T recievers
(image taken from
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20/11/2018

5. Outdoor measurements - objectives
Objectives of preliminary mesurements:
To determine protection ratios sufficient for normal DVB-T reception
To determine LTE performance with present DVB-T interference
3 different scenarios tested:
Same channel interference
Overlaping channels interference
1MHz gap between interfering channels (expected real case situation)
Preliminary measurements to test the interference concerns have been performed in July and results collected for analysis
HAKOM Open
20/11/2018

6. Outdoor measurements – test setup
TEST DVB-T TX
Outdoor measurements – test setup
Measurement vehicle equipped with:
R&S ETL (DVB-T reception evaluation)
R&S ESMD (field strenght measurement)
HL033 measurement antenna
4 commercial DVB-T receivers
Separate vehicle for LTE measurements
TEST DVB-T TX TEST LTE TX
Figure 3: Measurement setup
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20/11/2018

7. Outdoor measurements – test setup
DVB-T transmitter parameters:
Selectable transmitting power resulting in 5W - 1kW ERP
BW = 8MHz
64QAM
FEC 3/4
FFT 8k
LTE transmitter parameters
Selectable transmitting power resulting in 16W W ERP
Selectable BW: 5MHz, 10MHz, 20MHz
Full load simulation mode
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20/11/2018

8. Outdoor measurements – test setup
1MHz gap between DVB-T and LTE scenario
Figure 4: Channel spacing
Test DVB-T transmission on >790MHz to avoid interference to existing users
Real case scenario would be DVB-T channels on <790MHz with LTE on >791MHz
HAKOM Open
20/11/2018

9. Outdoor measurements - method
Evaluate DVB-T reception via ETL receiver (MER, BER)
Evaluate DVB-T reception via 4 comercial DVB-T receivers (subjective picture evaluation)
Reduce DVB-T Tx power and repeat reception evaluation until achieveing border case of acceptable reception (with LTE turned on)
Measure received signal levels from both LTE and DVB-T Tx
Repeat evaluation of DVB-T signal with switched off LTE Tx
Analyze results and draw a preliminary conclusion
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20/11/2018

10. Outdoor measurements - results
6 different measurement locations
DVB-T TX
LTE TX
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20/11/2018

11. Outdoor measurements - results
Example of measured parameters at border reception case:
EDVB-T=68dBμV/m
BER before RS (after Viterbi) ~ 2.3e-4 (LTE switched on)
ELTE =95,6dBμV/m
resulting C/I = -27,6dB
LTE Tx switch-off results in acceptable reception
Protection ratio according to ECC/TG4 work group is
-30,2dB for 1MHz separation between DVB-T and LTE channels. Other sources give C/I from -26 to -33dB.
HAKOM Open
20/11/2018

12. Conclusions
Preliminary measurements confirm that in certain cases LTE base stations could have impact on DVB-T reception
Measurements follow theoretical predictions, altough there are some differences between measured and predicted values, probably due to limited number of measurement points
Preliminary measurements give opportunity for improvement to future measurements method
HAKOM Open
20/11/2018

13. Future plans Laboratory measurements
Outdoor measurements on several locations, different transmitter settings
Measurements at different channel spacing (up to N+9)
Statistical evaluation of gathered results
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20/11/2018

14. Thank You!
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20/11/2018