6.6.2 Occupied bandwidth

37.145-13GPPActive Antenna System (AAS) Base Station (BS) conformance testingPart 1: conducted conformance testingRelease 17TS

Tools: ARFCN - Frequency Conversion for 5G NR/LTE/UMTS/GSM

6.6.2.1 Definition and applicability

The occupied bandwidth is the width of a frequency band such that, below the lower and above the upper frequency limits, the mean powers emitted are each equal to a specified percentage /2 of the total mean transmitted power. See also Recommendation ITU-R SM.328 [17].

The value of /2 shall be taken as 0.5%.

The occupied bandwidth requirement applies during the transmitter ON period for a single transmitted carrier. The minimum requirement below may be applied regionally. There may also be regional requirements to declare the occupied bandwidth according to the definition in the present clause.

6.6.2.2 Minimum requirement

For MSR AAS BS, the minimum requirement for occupied bandwidth is the same as that stated in TS 37.104 [12], clause 6.6.3.

For single RAT UTRA FDD AAS BS, the minimum requirement for occupied bandwidth is the same as that stated in TS 25.104 [9], clause 6.6.1.

For single RAT UTRA TDD, 1,28Mcps option AAS BS, the minimum requirement for occupied bandwidth is the same as that stated in TS 25.105 [10], clause 6.6.1.

For single RAT E-UTRA AAS BS, the minimum requirement for occupied bandwidth is the same as that stated in TS 36.104 [11], clause 6.6.1.

6.6.2.3 Test purpose

The test purpose is to verify that the emission of the TAB connector does not occupy an excessive bandwidth for the service to be provided and is, therefore, not likely to create interference to other users of the spectrum beyond undue limits.

6.6.2.4 Method of test

6.6.2.4.1 Initial conditions

6.6.2.4.1.1 General test conditions

Test environment:

– normal; see clause B.2.

RF channels to be tested:

– M; see clause 4.12.1.

6.6.2.4.1.2 UTRA FDD

Set the TAB connector to transmit a signal in accordance to TM1, clause 4.12.2.

6.6.2.4.1.3 UTRA TDD

Set the parameters of the BS transmitted signal according to table 6.6.2.4.1.3-1.

Table 6.6.2.4.1.3-1: Parameters of the TAB connector transmitted signal
for occupied bandwidth testing for 1,28 Mcps TDD

Parameter	Value/description
TDD Duty Cycle	TS i; i = 0, 1, 2, 3, 4, 5, 6: transmit, if i is 0,4,5,6; receive, if i is 1,2,3.
Time slots under test	TS4, TS5 and TS6
Number of DPCH in each time slot under test	8
Power of each DPCH	1/8 of Base Station output power
Data content of DPCH	real life (sufficient irregular)

6.6.2.4.1.4 E-UTRA and NR

Aggregated Channel Bandwidth positions to be tested for contiguous carrier aggregation:

– B_{BW Channel CA}, M_{BW Channel CA} and T_{BW Channel CA}; see clause 4.12.1.

For a AAS BS declared to be capable of single carrier operation, start transmission according to E- TM1.1 for E-UTRA or [NR-FR1-TM 1.1] for NR, clause 4.12.2.

6.6.2.4.2 Procedure

6.6.2.4.2.1 General Procedure

The minimum requirement is applied to all TAB connectors, they may be tested one at a time or multiple TAB connectors may be tested in parallel as shown in clause D.1.1. Whichever method is used the procedure is repeated until all TAB connectors necessary to demonstrate conformance have been tested.

1) Connect TAB connector to measurement equipment as shown in clause D.1.1. All TAB connectors not under test shall be terminated.

2) For UTRA and E-UTRA and NR declared capable of single carrier operation set the TAB connector to transmit at manufacturers declared rated carrier output power per TAB connector (P_Rated,c,TABC).

For E-UTRA and NR declared capable of contiguous carrier aggregation operation set the TAB connector to transmit on all carriers configured using the applicable test configuration and corresponding power setting specified in clause 5.

6.6.2.4.2.2 UTRA FDD

1) Measure the spectrum of the transmitted signal across a span of 10 MHz, based on an occupied bandwidth requirement of 5 MHz. The selected resolution bandwidth (RBW) filter of the analyser shall be 30 kHz or less. The spectrum shall be measured at 400 or more points across the measurement span.

NOTE: The detection mode of the spectrum analyzer will not have any effect on the result if the statistical properties of the out-of-OBW power are the same as those of the inside-OBW power. Both are expected to have the Rayleigh distribution of the amplitude of Gaussian noise. In any case where the statistics are not the same, though, the detection mode is power responding. There are at least two ways to be power responding. The spectrum analyser can be set to "sample" detection, with its video bandwidth setting at least three times its RBW setting. Or the analyser may be set to respond to the average of the power (root-mean-square of the voltage) across the measurement cell.

2) Compute the total of the power, P0, (in power units, not decibel units) of all the measurement cells in the measurement span. Compute P1, the power outside the occupied bandwidth on each side. P1 is half of the total power outside the bandwidth. P1 is half of (100 % – (occupied percentage)) of P0. For the occupied percentage of 99 %, P1 is 0.005 times P0.

3) Determine the lowest frequency, f1, for which the sum of all power in the measurement cells from the beginning of the span to f1 exceeds P1.

4) Determine the highest frequency, f2, for which the sum of all power in the measurement cells from the end of the span to f2 exceeds P1.

5) Compute the occupied bandwidth as f2 – f1.

In addition, for multi-band TAB connector(s), the following steps shall apply:

6) For multi-band TAB connectors and single band tests, repeat the steps above per involved band where single band test configurations and test models shall apply with no carrier activated in the other band.

6.6.2.4.2.3 UTRA TDD

1) Measure the power of the transmitted signal with a measurement filter of bandwidth 30 kHz. The characteristic of the filter shall be approximately Gaussian (typical spectrum analyser filter). The centre frequency of the filter shall be stepped in contiguous 30 kHz steps from a minimum frequency, which shall be (2,4 – 0,015) MHz below the assigned channel frequency of the transmitted signal, up to a maximum frequency, which shall be (2,4 ‑ 0,015) MHz above the assigned channel frequency of the transmitted signal. The time duration of each step shall be sufficiently long to capture one active time slot. The measured power shall be recorded for each step.

2) Determine the total output power by accumulating the recorded power measurement results of all steps.

3) Sum up the recorded power measurement results, starting from the step at the minimum frequency defined in (3) up to the step at a lower limit frequency by which this sum is equal to or greater than 0,5 % of the total output power determined in (4). This limit frequency is recorded as "Lower Frequency".

4) Sum up the recorded power measurement results, starting from the step at the maximum frequency defined in (3) down to the step at an upper limit frequency by which this sum is equal to or greater than 0,5 % of the total output power determined in (4). This limit frequency is recorded as "Upper Frequency".

5) Calculate the occupied bandwidth as the difference between the "Upper Frequency" obtained in (5) and the "Lower Frequency" obtained in (6).

In addition, for multi-band TAB connector(s), the following steps shall apply:

6.6.2.4.2.4 E-UTRA and NR

1) Measure the spectrum emission of the transmitted signal using at least the number of measurement points, and across a span, as listed in table 6.6.2.4.2.4-1 for E-UTRA and 6.6.2.4.2.4-2 for NR. The selected resolution bandwidth (RBW) filter of the analyser shall be 30 kHz or less.

Table 6.6.2.4.2.4-1: Span and number of measurement points for OBW measurements

Bandwidth	E-UTRA channel bandwidth BW_Channel (MHz)						Aggregated channel bandwidth BW_{Channel_CA} (MHz)
	1.4	3	5	10	15	20	> 20
Span (MHz)	10	10	10	20	30	40
Minimum number of measurement points	1429	667	400	400	400	400

Table 6.6.2.4.2.4-2: Span and number of measurement points for OBW measurements for NR

Bandwidth	BS channel bandwidth BW_Channel (MHz)					Aggregated BS channel bandwidth BW_{Channel_CA}（MHz）
	5	10	15	20	> 20	> 20
Span (MHz)	10	20	30	40
Minimum number of measurement points	400	400	400	400	[]	[]
[NOTE 1: T = 200 kHz, when the BS channel bandwidth of outermost carriers are both larger than 50 MHz; Otherwise, T = 100 kHz.]

NOTE: The detection mode of the spectrum analyzer will not have any effect on the result if the statistical properties of the out-of-OBW power are the same as those of the inside-OBW power. Both are expected to have the Rayleigh distribution of the amplitude of Gaussian noise. In any case where the statistics are not the same, though, the detection mode is power responding. The analyser may be set to respond to the average of the power (root-mean-square of the voltage) across the measurement cell.

3) Determine the lowest frequency, f1, for which the sum of all power in the measurement cells from the beginning of the span to f1 exceeds P1.

4) Determine the highest frequency, f2, for which the sum of all power in the measurement cells from f2 to the end of the span exceeds P1.

5) Compute the occupied bandwidth as f2 – f1.

In addition, for multi-band TAB connector(s), the following steps shall apply:

6.6.2.5 Test requirements

6.6.2.5.1 MSR

The occupied bandwidth of a single carrier shall be less than the values listed in table 6.6.2.5.1-1. In addition, for E‑UTRA and NR intra-band contiguous carrier aggregation, test requirement in clause 6.6.1.5 of TS 36.141 [17] or clause 6.6.2.5 of TS 38.141-1 [37] applies for the E-UTRA or NR component carriers that are aggregated.

Table 6.6.2.5.1-1: Occupied bandwidth

RAT	Occupied bandwidth limit
E-UTRA and NR	BW_Channel
UTRA FDD	5 MHz
1.28 Mcps UTRA TDD	1.6 MHz

6.6.2.5.2 UTRA FDD

The occupied bandwidth shall be less than 5 MHz based on a chip rate of 3,84 Mcps.

NOTE: If the above Test Requirement differs from the Minimum Requirement then the Test Tolerance applied for this test is non-zero. The Test Tolerance for this test is defined in clause 4.1.2 and the explanation of how the Minimum Requirement has been relaxed by the Test Tolerance is given in annex C.

6.6.2.5.3 UTRA TDD

The occupied bandwidth shall be less than 1,6 MHz.

6.6.2.5.4 E-UTRA

The occupied bandwidth for each E-UTRA carrier shall be less than the channel bandwidth. For contiguous CA, the occupied bandwidth shall be less than or equal to the Aggregated Channel Bandwidth as defined in TS 36.141 [17] clause 5.6.