B.7 Interference models for enhanced downlink control channel performance requirements Type A and B

36.1013GPPEvolved Universal Terrestrial Radio Access (E-UTRA)Release 18TSUser Equipment (UE) radio transmission and reception

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

This clause provides a description for the modelling of interfering cell transmissions for the enhanced downlink control channel performance requirements Type A and B.

B.7.1 PDCCH, PCFICH and PHICH interference model

This subclause provides a description of the interfering cell transmissions model for the enhanced PDCCH/PCFICH and PHICH downlink control channel performance requirements Type A and B under synchronous network scenarios.

The transmitted physical signals and channels shall include CRS, PSS, SSS, PBCH and PCFICH. The PDCCH and PHICH transmit signals are emulated as virtual PDCCH signals described further in the clause.

The PDCCH signals are modelled with a per control channel element (CCE) level granularity and have guaranteed 50% CCE resource loading in each subframe. For each subframe the set of active and inactive CCEs is derived in accordance to the following procedure:

1) All available CCEs for the PDCCH and PHICH are marked as CCE₀, CCE₁, …, CCE_N-1.

2) For the given partial loading ratio X = 50% the numbers of active CCEs M_Active and inactive CCEs M_Inactive are derived

3) The indexes of M_Inactive inactive CCEs are randomly selected out of the full set of CCEs.

4) The remaining M_Active CCEs are assigned to be active.

No signals are transmitted in the REs corresponding to the inactive CCEs. The PDCCH signals are transmitted in the REs corresponding to the active CCEs. For PDCCH REs, precoding for transmit diversity for the number of antenna ports in the requirement scenario shall be applied to QPSK randomly modulated layer symbols, as specified in subclause 6.3.4.3 of [4]. The EPRE ratio of the PDCCH REs in the active CCEs shall be derived in accordance to the following procedure:

1) For each generated active i-th CCE the PDCCH power boosting level shall be randomly generated using the uniform distribution in the [Pmin, Pmax] range. The Pmin is equal to -6 dB, the Pmax is equal to 6 dB. The random values should be derived in the dB scale.

2) Additional power normalization is applied for each generated i-th PDCCH power boosting level:

where and are the PDCCH power boosting coefficients before and after normalization in the dB scale; the power normalization factor α is equal to 1.3 dB.

3) The normalized PDCCH power boosting coefficients are further applied to the PDCCH_RA and PDCCH_RB values to derive the EPRE ratio of the PDCCH signals transmitted in the REs corresponding the i-th CCE in each subframe.