10 Modulation accuracy
25.1433GPPRelease 17TSUTRA repeater conformance testing
In this section the procedure for testing the modulation accuracy of Repeaters is defined. This test includes EVM and peak code domain error.
10.1 Error vector magnitude
In this section the procedure for testing the Error Vector Magnitude (EVM) of Repeaters is defined.
10.1.1 Definition and applicability
The Error Vector Magnitude is a measure of the difference between the theoretical waveform and a modified version of the measured waveform. The modification is done according to annex E of TS25.141. This difference is called the error vector. The EVM result is defined as the square root of the ratio of the mean error vector power to the modified mean reference signal power expressed as a %. The measurement interval is one power control group (timeslot).
10.1.2 Minimum Requirements
In normal conditions as specified in section 5.4.1 the Error Vector Magnitude shall not be worse than 12,5 % as defined in TS25.106.
10.1.3 Test purpose
To verify that the EVM is within the limit specified in 10.1.2 after the signal passed through the Repeater..
10.1.4 Method of test
10.1.4.1 Initial conditions
Set-up the equipment as shown in annex A.
The test is based upon the test for the base station. Test model 1 as described in TS25.141 is used for the definition of the signal to test on. A signal generator providing the required signals is connected to the input of the Repeater. The Repeater is set to operate at full gain. The signal level is adjusted to the equivalent level to obtain the nominal output power as declared by the manufacturer. A signal analyser connected to the output is used to measure the EVM value.
10.1.4.2 Procedure
The test has to be performed in the uplink and the downlink path of the Repeater. The EVM has to be measured according to Annex E of TS25.141
10.1.4.3 Stimulus EVM effect
The stimulus signal generator EVM will RSS with the tested repeater EVM. The target for the recorded value is adjusted accordingly in the test requirements.
10.1.5 Test requirements
In normal conditions as specified in section 5.4.1, the Error Vector Magnitude, as defined in TS25.106, shall not exceed 13,2%.
10.2 Peak code domain error
In this section the procedure for testing the Peak Code Domain Error of Repeaters is defined.
10.2.1 Definition and applicability
The Peak Code Domain Error is computed by projecting the error vector onto the code domain at a specific spreading factor. The Code Domain Error for every code in the domain is defined as the ratio of the mean power of the projection onto that code, to the mean power of the composite reference waveform. This ratio is expressed in dB. The Peak Code Domain Error is defined as the maximum value for the Code Domain Error for all codes. The measurement interval is one power control group (timeslot).
10.2.2 Minimum Requirements
In normal conditions as specified in section 5.4.1 the peak code domain error shall not exceed -35 dB at spreading factor 256 as defined in TS25.106.
10.2.3 Test purpose
To verify that the peak code domain error is within the limit specified in 10.2.2 after the signal passed through the Repeater.
10.2.4 Method of test
10.2.4.1 Initial conditions
Set-up the equipment as shown in annex A.
The test is based upon the test for the base station. Test model 3 as described in TS25.141 is used for the definition of the signal to test on. A signal generator providing the required signals is connected to the input of the Repeater. The spreading factor of the signal generator is set to 256. The Repeater is set to operate at full gain. The signal level is adjusted to the equivalent level to obtain the nominal output power as declared by the manufacturer. A signal analyser connected to the output is used to measure the peak code domain error value.
10.2.4.2 Procedure
The test has to be performed in the uplink and the downlink path of the Repeater. The peak code domain error as described in TS25.141 Annex E has to be measured.
10.2.5 Test requirements
In normal conditions as specified in section 5.4.1 the peak code domain error shall not exceed -33,9 dB at spreading factor 256 as defined in TS25.106.
10.3 Relative Code Domain Error (RCDE) for 64QAM modulation
10.3.1 Definition and applicability
The Relative Code Domain Error is computed by projecting the error vector (as defined in 10.1) onto the code domain at a specified spreading factor. Only the active code channels in the composite reference waveform are considered for this requirement. The Relative Code Domain Error for every active code is defined as the ratio of the mean power of the error projection onto that code, to the mean power of the active code in the composite reference waveform. This ratio is expressed in dB. The measurement interval is one frame.
The requirement for Relative Code Domain Error is only applicable for Repeater supporting 64QAM modulated codes.
See TS25.141 [11] Annex E for further details.
10.3.2 Minimum requirement
The average Relative Code Domain Error for 64QAM modulated codes shall not exceed -21 dB at spreading factor 16.
10.3.3 Test purpose
To verify that the peak code domain error is within the limit specified in 10.3.2 after the signal passed through the Repeater.
10.3.4 Method of test
10.3.4.1 Initial conditions
Set-up the equipment as shown in annex A.
The test is based upon the test for the base station. Test model 6 as described in TS25.141 is used for the definition of the signal to test on. A signal generator providing the required signals is connected to the input of the Repeater. The spreading factor of the signal generator is set to 16. The Repeater is set to operate at full gain. The signal level is adjusted to the equivalent level to obtain the nominal output power as declared by the manufacturer. A signal analyser connected to the output is used to measure the peak code domain error value.
10.3.4.2 Procedure
The test has to be performed in the uplink and the downlink path of the Repeater. The relative code domain error as described in TS25.141 Annex E has to be measured.
10.3.5 Test requirements
In normal conditions as specified in section 5.4.1 the relative code domain error shall not exceed -19.3 dB at spreading factor 16 as defined in TS25.106.