12 Output intermodulation
25.1433GPPRelease 17TSUTRA repeater conformance testing
The output intermodulation requirement is a measure of the ability of the repeater to inhibit the generation of intermodulation products signals created by the presence of an interfering signal reaching the repeater via the output port.
12.1 Definition and applicability
The output intermodulation level is the power of the intermodulation products when a WCDMA modulated interference signal is injected into the output port at a level of 30 dB lower than that of the wanted signal. The frequency of the interference signal shall be 5 MHz, 10 MHz and 15 MHz offset from the wanted signal, but within the frequency band allocated for UTRA FDD downlink as specified in subclause 4.1.
The requirement is applicable for downlink signals.
The normative reference for this requirement is in TS25.106 [12] section 12.
12.2 Minimum requirement
In normal conditions as specified in section 5.4.1, the output intermodulation level shall not exceed the out of band emission or the spurious emission requirements of section 9.1 and 9.2.
12.3 Test purpose
The test purpose is to verify the ability of the repeater to restrict the generation of intermodulation products in the presence of a subject signal on the repeater input and output ports, and an interfering signal applied at the repeater output port.
12.4 Method of test
12.4.1 Initial conditions
1) Set-up the equipment as shown in annex A.
2) Connect a signal generator to the input port of the Repeater for tests of repeaters with a pass band corresponding to one 5 MHz channel. Connect a signal generator to the circulator on the output port and make sure the signal generator power is directed to the repeater output port.
3) Measurements with an offset from the carrier centre frequency between 2,515 MHz and 4,0 MHz shall use a 30 kHz measurement bandwidth.
4) Measurements with an offset from the carrier centre frequency between 4,0 MHz and (fmax – 500 kHz) shall use a 1 MHz measurement bandwidth. The 1MHz measurement bandwidth may be calculated by integrating multiple 50 kHz or narrower filter measurements
5) Detection mode: True RMS.
12.4.2 Procedures
1) Set the Repeater to maximum gain.
2) Set the signal generator at the repeater input port (subject signal) to generate a signal in accordance to test model 1, TS 25.141 subclause 6.1.1.1, at the level which produce the manufacturer specified maximum output power at maximum gain.
3) Set the signal generator at the repeater output port (interference signal) to generate a signal in accordance to test model 1, TS 25.141 subclause 6.1.1.1, at the level producing signal power corresponding to 30 dB below the manufacturer specified maximum output power at the repeater output port with the specified frequency offset from the wanted signal.
4) Measure the emission at the specified frequencies with specified measurement bandwidth and note that the measured value does not exceed the specified value. Measurements in the band of the interfering signal shall be excluded. The measurements can be limited to the power of all third and fifth order intermodulation products.
5) Repeat from clause 3 until interference signals 5 MHz, 10 MHz and 15 MHz frequency offset from the wanted signal has been tested. Note that interfering signals outside the UTRA-FDD allocated frequency band , as specifies in section 4.1. need not be tested.
12.5 Test requirements
In all measurements, the requirements according to sections 9.1.1.5 and the downlink requirements in section 9.2.2.1 or 9.2.2.2 shall be fulfilled.