11 Input Intermodulation
25.1533GPPRelease 17TSUTRA repeater conformance testing (LCR TDD)
The input intermodulation is a measure of the capability of the repeater to inhibit the generation of interference in the pass band, in the presence of interfering signals on frequencies other than the pass band.
11.1 Definition and applicability
Third and higher order mixing of the two interfering RF signals can produce an interfering signal in the band of the desired channel. Intermodulation response rejection is a measure of the capability of the Repeater to maintain the wanted frequency free of internally created interference.
This test applies to uplink and downlink path of the Repeater.
11.2 Minimum requirement
11.2.1 General requirement
For the parameters specified in table 11.1, the power in the pass band shall not increase with more than 10 dB at the output of the repeater as measured in the centre of the pass band, compared to the level obtained without interfering signals applied.
The frequency separation between the two interfering signals shall be adjusted so that the 3rd order intermodulation product is positioned in the centre of the pass band.
Table 11.1 specifies the parameters for two interfering signals, where:
– f1 offset is the offset from the channel edge frequency of the first or last channel in the pass band of the closer carrier.
Table 11.1: Input intermodulation requirement
f1 offset |
Interfering Signal Levels |
Type of signals |
Measurement bandwidth |
1,0 MHz |
-40 dBm |
2 CW carriers |
1 MHz |
11.2.2 Co-location with BS in other systems
This additional input intermodulation requirement may be applied for the protection of TDD Repeater input when GSM900, DCS1800, PCS1900, GSM850, UTRA FDD, UTRA TDD and/or E-UTRA BS are co-located with an LCR TDD Repeater.
Unless otherwise stated this requirement applies to the uplink and downlink of the repeater, at maximum gain.
For the parameters specified in table 11.2, the power in the pass band shall not increase with more than 10 dB at the output of the repeater as measured in the centre of the pass band, compared to the level obtained without interfering signals applied.
The frequency separation between the two interfering signals shall be adjusted so that the lowest order intermodulation product is positioned in the centre of the pass band.
NOTE 1: The lowest intermodulation products correspond to the 4th and 3rd order for the GSM 900 and DCS 1800 bands, respectively.
Table 11.2: Input intermodulation requirements for interfering signals in co-located other systems
Co-located other systems |
Frequency of interfering signals |
Interfering Signal Levels |
Type of signals |
Measurement bandwidth |
Note |
GSM900 |
921 ‑ 960 MHz |
+16 dBm |
2 CW carriers |
1 MHz |
|
DCS1800 |
1805 ‑ 1880 MHz |
+16 dBm |
2 CW carriers |
1 MHz |
|
PCS1900 |
1930 – 1990 MHz |
+16 dBm |
2 CW carriers |
1 MHz |
|
GSM850 |
869 – 894 MHz |
+16 dBm |
2 CW carriers |
1 MHz |
|
UTRA-FDD Band I or |
2110 – 2170 MHz |
+16 dBm |
2 CW carriers |
1 MHz |
|
UTRA-FDD Band II or |
1930 – 1990 MHz |
+16 dBm |
2 CW carriers |
1 MHz |
|
UTRA-FDD Band III or |
1805 – 1880 MHz |
+16 dBm |
2 CW carriers |
1 MHz |
|
UTRA-FDD Band IV or |
2110 – 2155 MHz |
+16 dBm |
2 CW carriers |
1 MHz |
|
UTRA-FDD Band V or |
869 – 894 MHz |
+16 dBm |
2 CW carriers |
1 MHz |
|
UTRA-FDD Band VI or |
875 – 885 MHz |
+16 dBm |
2 CW carriers |
1 MHz |
|
UTRA-FDD Band VII or |
2620 – 2690 MHz |
+16 dBm |
2 CW carriers |
1 MHz |
|
UTRA-FDD Band VIII or |
925 – 960 MHz |
+16 dBm |
2 CW carriers |
1 MHz |
|
UTRA-FDD Band IX or |
1844.9 – 1879.9 MHz |
+16 dBm |
2 CW carriers |
1 MHz |
|
UTRA-FDD Band X or |
2110 – 2170 MHz |
+16 dBm |
2 CW carriers |
1 MHz |
|
UTRA-FDD Band XI or |
1475.9 – 1500.9 MHz |
+16 dBm |
2 CW carriers |
1 MHz |
|
UTRA FDD Band XII or |
728 – 746 MHz |
+16 dBm |
2 CW carriers |
1 MHz |
|
UTRA FDD Band XIII or |
746 – 756 MHz |
+16 dBm |
2 CW carriers |
1 MHz |
|
UTRA FDD Band XIV or |
758 – 768 MHz |
+16 dBm |
2 CW carriers |
1 MHz |
|
UTRA TDD in Band a) or |
1900 – 1920 MHz |
+16 dBm |
2 CW carriers |
1 MHz |
This requirement does not apply to LCR TDD Repeater operating in band a), since it is already covered by the requirement in sub-clause 11.1, but requires a 86dB coupling loss between base station and the repeater DL receive port. |
UTRA TDD in Band a) or |
2010 – 2025 MHz |
+16 dBm |
2 CW carriers |
1 MHz |
This requirement does not apply to LCR TDD Repeater operating in band a), since it is already covered by the requirement in sub-clause 11.1, but requires a 86dB coupling loss between base station and the repeater DL receive port. |
UTRA TDD in Band b) or |
1850 – 1910 MHz |
+16 dBm |
2 CW carriers |
1 MHz |
This requirement does not apply to LCR TDD Repeater operating in band b), since it is already covered by the requirement in sub-clause 11.1, but requires a 86dB coupling loss between base station and the repeater DL receive port. |
UTRA TDD in Band b) or |
1930 – 1990 MHz |
+16 dBm |
2 CW carriers |
1 MHz |
This requirement does not apply to LCR TDD Repeater operating in band b), since it is already covered by the requirement in sub-clause 11.1, but requires a 86dB coupling loss between base station and the repeater DL receive port. |
UTRA TDD in Band c) or |
1910 – 1930 MHz |
+16 dBm |
2 CW carriers |
1 MHz |
This requirement does not apply to LCR TDD Repeater operating in band c), since it is already covered by the requirement in sub-clause 11.1, but requires a 86dB coupling loss between base station and the repeater DL receive port. |
UTRA TDD in Band d) or |
2570 – 2620 MHz |
+16 dBm |
2 CW carriers |
1 MHz |
This requirement does not apply to LCR TDD Repeater operating in band d), since it is already covered by the requirement in sub-clause 11.1, but requires a 86dB coupling loss between base station and the repeater DL receive port. |
UTRA TDD in Band e) or E-UTRA Band 40 |
2300 – 2400 MHz |
+16 dBm |
2 CW carriers |
1 MHz |
This requirement does not apply to LCR TDD Repeater operating in band e), since it is already covered by the requirement in sub-clause 11.1, but requires a 86dB coupling loss between base station and the repeater DL receive port. |
UTRA TDD in Band f) or E-UTRA Band 39 |
1880 – 1920 MHz |
+16 dBm |
2 CW carriers |
1 MHz |
This requirement does not apply to LCR TDD Repeater operating in band f), since it is already covered by the requirement in sub-clause 11.1, but requires a 86dB coupling loss between base station and the repeater DL receive port. |
NOTE 1: The co-location requirements in Table 11.2 do not apply when the repeaters pass band frequency range is adjacent to the band for the co-location requirement in the Table 11.2. The current state-of-the-art technology does not allow a single generic solution for co-location with other system on adjacent frequencies for 30dB Repeater-BS minimum coupling loss. However, there are certain site-engineering solutions that can be used. These techniques are addressed in TR 25.942 [13].
NOTE 2: The Table 11.2 assumes that two operating bands, where the corresponding transmit and receive frequency ranges would be overlapping, are not deployed in the same geographical area. For such a case of operation with overlapping frequency arrangements in the same geographical area, special co-location requirements may apply that are not covered by the 3GPP specifications.
11.2.3 Co-existence with other systems
This additional input intermodulation requirement may be applied when GSM900, DCS1800, PCS1900, GSM850, UTRA FDD, UTRA TDD and/or E-UTRA BS operating in another frequency band co-exist with an E-UTRA FDD Repeater.
Unless otherwise stated this requirement applies to the uplink and downlink of the repeater, at maximum gain.
For the parameters specified in table 11.3, the power in the pass band shall not increase with more than 10 dB at the output of the repeater as measured in the centre of the pass band, compared to the level obtained without interfering signals applied.
The frequency separation between the two interfering signals shall be adjusted so that the lowest order intermodulation product is positioned in the centre of the pass band.
NOTE 1: The lowest intermodulation products correspond to the 4th and 3rd order for the GSM 900 and DCS 1800 bands, respectively.
Table 11.3: Input intermodulation requirements for interfering signals in co-existing other systems
Co-existence with other systems |
Frequency of interfering signals |
Interfering Signal Levels |
Type of signals |
Measurement bandwidth |
Note |
GSM900 |
876 – 915 MHz |
-15 dBm |
2 CW carriers |
1 MHz |
|
DCS1800 |
1710 ‑ 1785 MHz |
-15 dBm |
2 CW carriers |
1 MHz |
|
PCS1900 |
1850 ‑ 1910 MHz |
-15 dBm |
2 CW carriers |
1 MHz |
|
GSM850 |
824 ‑ 849 MHz |
-15 dBm |
2 CW carriers |
1 MHz |
|
UTRA FDD Band I or |
1920 – 1980 MHz |
-15 dBm |
2 CW carriers |
1 MHz |
|
UTRA FDD Band II or |
1850 – 1910 MHz |
-15 dBm |
2 CW carriers |
1 MHz |
|
UTRA FDD Band III or |
1710 – 1785 MHz |
-15 dBm |
2 CW carriers |
1 MHz |
|
UTRA FDD Band IV or |
1710 – 1755 MHz |
-15 dBm |
2 CW carriers |
1 MHz |
|
UTRA FDD Band V or |
824 – 849 MHz |
-15 dBm |
2 CW carriers |
1 MHz |
|
UTRA FDD Band VI or |
815 – 850 MHz |
-15 dBm |
2 CW carriers |
1 MHz |
|
UTRA FDD Band VII or |
2500 – 2570 MHz |
-15 dBm |
2 CW carriers |
1 MHz |
|
UTRA FDD Band VIII or |
880 – 915 MHz |
-15 dBm |
2 CW carriers |
1 MHz |
|
UTRA FDD Band IX or |
1749.9 – 1784.9 MHz |
-15 dBm |
2 CW carriers |
1 MHz |
|
UTRA FDD Band X or |
1710 – 1770 MHz |
-15 dBm |
2 CW carriers |
1 MHz |
|
UTRA FDD Band XI or |
1427.9 – 1452.9 MHz |
-15 dBm |
2 CW carriers |
1 MHz |
|
UTRA FDD Band XII or |
698 – 716 MHz |
-15 dBm |
2 CW carriers |
1 MHz |
|
UTRA FDD Band XIII or |
777 – 787 MHz |
-15 dBm |
2 CW carriers |
1 MHz |
|
UTRA FDD Band XIV or |
788 – 798 MHz |
-15 dBm |
2 CW carriers |
1 MHz |
|
UTRA TDD in Band a) or |
1900 – 1920 MHz |
-15 dBm |
2 CW carriers |
1 MHz |
This requirement does not apply to LCR TDD Repeater operating in band a), since it is already covered by the requirement in sub-clause 11.1. |
UTRA TDD in Band a) or |
2010 – 2025 MHz |
-15 dBm |
2 CW carriers |
1 MHz |
This requirement does not apply to LCR TDD Repeater operating in band a), since it is already covered by the requirement in sub-clause 11.1. |
UTRA TDD in Band b) or |
1850 – 1910 MHz |
-15 dBm |
2 CW carriers |
1 MHz |
This requirement does not apply to LCR TDD Repeater operating in band b), since it is already covered by the requirement in sub-clause 11.1. |
UTRA TDD in Band b) or |
1930 – 1990 MHz |
-15 dBm |
2 CW carriers |
1 MHz |
This requirement does not apply to LCR TDD Repeater operating in band b), since it is already covered by the requirement in sub-clause 11.1. |
UTRA TDD in Band c) or |
1910 – 1930 MHz |
-15 dBm |
2 CW carriers |
1 MHz |
This requirement does not apply to LCR TDD Repeater operating in band c), since it is already covered by the requirement in sub-clause 11.1. |
UTRA TDD in Band d) or |
2570 – 2620 MHz |
-15 dBm |
2 CW carriers |
1 MHz |
This requirement does not apply to LCR TDD Repeater operating in band d), since it is already covered by the requirement in sub-clause 11.1. |
UTRA TDD in Band e) or E-UTRA Band 40 |
2300 – 2400 MHz |
-15 dBm |
2 CW carriers |
1 MHz |
This requirement does not apply to LCR TDD Repeater operating in band e), since it is already covered by the requirement in sub-clause 11.1. |
UTRA TDD in Band f) or E-UTRA Band 39 |
1880 – 1920 MHz |
-15 dBm |
2 CW carriers |
1 MHz |
This requirement does not apply to LCR TDD Repeater operating in band f), since it is already covered by the requirement in sub-clause 11.1. |
NOTE 1: The co-existence requirements in Table 11.3 do not apply when the repeaters pass band frequency range is adjacent to the band for the co-existence requirement in the Table 11.3. The current state-of-the-art technology does not allow a single generic solution for co-existence.
NOTE 2: The Table 11.3 assumes that two operating bands, where the frequency ranges would be overlapping, are not deployed in the same geographical area. For such a case of operation with overlapping frequency arrangements in the same geographical area, special co-existence requirements may apply that are not covered by the 3GPP specifications.
11.3 Test purpose
The purpose of this test is to verify that the Repeater meets the intermodulation characteristics requirements as specified by the minimum requirements.
11.4 Method of test
11.4.1 Initial conditions
1) A measurement system set-up is shown in annex A.
2) Set the Repeater to maximum gain.
3) Connect two signal generators with a combining circuit or one signal generator with the ability to generate several CW carriers to the input.
4) Connect a spectrum analyser to the output of the Repeater. Set the resolution bandwidth to 1 MHz in the centre of the pass band. Set averaging to 1 second or more.
11.4.2 Procedure
1) Adjust the frequency of the input signals, either below or above the pass band, so that one carrier, f1, is 1 MHz outside the channel edge frequency of the first or last channel in the pass band, and the lowest order intermodulation product from the two carriers is positioned in the centre of the pass band, according to subclause 11.2.
2) Take the measurement of the rise of the output signal.
3) Repeat the measurement for the opposite path of the Repeater.
11.5 Test requirements
The Input intermodulation measured according to subclause 11.4.2 shall not exceed the limits specified in the relevant tables of 11.2.