6.9 Intra Base Station System intermodulation attenuation, MXM 850 and MXM 1900

3GPP51.021Base Station System (BSS) equipment specificationRadio aspectsRelease 17TS

6.9.1 Test purpose

To verify that the level of intermodulation products (due to the leakage of RF power between transmitters that are operating in close vicinity of each other inside the BSS, or are combined to feed a single antenna) do not exceed the specified limit.

6.9.2 Test cases

6.9.2.1 200 kHz carriers-only

If SFH is supported by the BSS, it shall be disabled during this measurement.

The BSS shall be configured with a full complement of transceivers. Each RF transmit equipment shall be operated at the maximum power specified (Highest Static Power Control Level, subclause 6.3) and with modulation of a pseudo random sequence applied.

The equipment shall be operated at equal and minimum carrier frequency spacing specified for the BSS configuration under test.

For frequency offsets above the uppermost and below the lowermost carrier frequencies of more than 1.2 MHz and within the relevant TX band the average power of any intermodulation components shall be measured with a bandwidth of 200 kHz, zero frequency span, over a time slot period. The reference power for relative measurements is the average power measured in a bandwidth of 300 kHz for the TRX under test.

6.9.2.2 200 kHz and ANSI-136 30 kHz carriers

A BSS comprised of both ANSI-136 30 kHz carriers (see TIA-EIA-136-C) and 200 kHz carriers, shall be configured with a full complement of transceivers. Each RF transmit equipment shall be operated at the maximum power specified (Static Level 0 subclause 6.3 or, in the case of 30 kHz channels, as specified in TIA-EIA-136-C part 280) and with modulation of a pseudo random sequence applied.

The equipment shall be operated at equal and minimum carrier frequency spacing specified for each carrier type operating in the BSS configuration under test.

For frequency offsets above the uppermost and below the lowermost carrier frequencies, of more than 1.2 MHz and within the relevant TX band, the average power of any intermodulation components shall be measured as follows.

Two measurement types shall be made:

(a) For each 30 kHz carrier, measure the reference average power, in a 30 kHz bandwidth and in accordance with TIA/EIA-136 part 280, section 3.4.4. Then, for all intermodulation products, measure, in a 30 kHz bandwidth and in average power mode, the power relative to the carrier reference power.

(b) For each 200 kHz carrier, measure the reference average power, in a 300 kHz bandwidth and averaged over a time slot period in zero frequency span. Then, for all intermodulation products, measure, in a 200 kHz bandwidth and in average power mode, the power relative to the carrier reference power.

6.9.3 Void

6.9.4 Conformance requirement

Test Environment

Normal:

Minimum requirement

The average value of the measured intermodulation products shall not exceed:

(a) -60 dBc, relative to the 30 kHz carrier average power and

(b) -60 dBc, relative to the 200 kHz carrier average power.

6.9.5 Requirement reference

3GPP TS 45.005 subclause 4.7.2.