6.6.1 General

37.1053GPPActive Antenna System (AAS) Base Station (BS) transmission and receptionRelease 17TS

Unwanted emissions consist of so-called out-of-band emissions and spurious emissions according to ITU definitions ITU-R SM.329 [14]. In ITU terminology, out of band emissions are unwanted emissions immediately outside the channel bandwidth resulting from the modulation process and non-linearity in the transmitter but excluding spurious emissions. Spurious emissions are emissions which are caused by unwanted transmitter effects such as harmonics emission, parasitic emission, intermodulation products and frequency conversion products, but exclude out of band emissions.

For AAS BS in single RAT E-UTRA operation and MSR operation, the out-of-band emissions requirement for the AAS BS transmitter is specified in terms of an operating band unwanted emissions requirement that defines limits for emissions in each supported downlink operating band plus the frequency ranges ΔfOBUE above and ΔfOBUE below each band, where ΔfOBUE is the maximum offset of the operating band unwanted emission mask from the operating band edge. Emissions outside of this frequency range are limited by a spurious emissions requirement. For UTRA FDD single RAT AAS BS, the out of band emission requirement for AAS BS transmitter is specified in terms of spectrum emission mask requirement.

The values of ΔfOBUE are defined for hybrid AAS BS for E-UTRA and UTRA operating bands in Table 6.6.1-1.

Table 6.6.1-1: Maximum offset of OBUE outside the downlink operating band

BS type

Operating band characteristics


Hybrid AAS BS

FDL_high – FDL_low < 100 MHz


100 MHz ≤ FDL_high – FDL_low ≤ 900 MHz


The unwanted emission level limit of a TAB connector TX min cell group is in general defined by the unwanted emission basic limit which is the same as the corresponding applicable non-AAS BS per transmitter requirement specified in 3GPP TS 25.104 [2], 3GPP TS 25.105 [3], 3GPP TS 36.104 [4] or 3GPP TS 37.104 [5], and its scaling by NTXU,countedpercell. The unwanted emission requirements are applied per the TAB connector TX min cell groups for all the configurations supported by the AAS BS. The basic limits and corresponding scaling are defined in each relevant subclause.

There is in addition a requirement for occupied bandwidth and an ACLR requirement.