Q.1 Interferer configurations in downlink

3GPP45.005GSM/EDGE Radio transmission and receptionTS

Four different interference scenarios are defined for VAMOS downlink as follows:

Table Q.1-1 Reference Test Scenario for synchronous single co-channel interferer

Reference Test Scenario	Interfering Signal	Interferer relative power level	TSC	Interferer Delay range
VDTS-1	Co-channel 1	–	none	no delay

Table Q.1-2 Reference Test Scenarios for synchronous multiple interferers

Reference Test Scenario	Interfering Signal	Interferer power level relative to Co-channel 1	TSC	Interferer Delay range
VDTS-2	Co-channel 1 Co-channel 2 Adjacent 1 AWGN	– -10 dB 3 dB -17 dB	none none none –	no delay no delay no delay –

Table Q.1-3 Reference Test Scenario for asynchronous single co-channel interferer

Reference Test Scenario	Interfering Signal	Interferer relative power level	TSC	Interferer Delay
VDTS-3	Co-channel 1	–	none	74 symbols
Note: In calculating I1, the power of the delayed interferer burst is averaged over the active part of the wanted signal burst.

Table Q.1-4 Reference Test Scenario for synchronous single adjacent channel interferer

Reference Test Scenario	Interfering Signal	Interferer relative power level	TSC	Interferer Delay
VDTS-4	Adjacent 1	–	none	no delay

In all reference test scenarios in tables Q.1-1 to Q.1-4, the co channel and adjacent channel interferers are AQPSK modulated with SCPIR_DL = 0 dB. The power of the interferer is measured before any receiver filtering and during the active part of the desired burst (see 3GPP TS 45.004). No Training Sequence Code (TSC) is used for the interferers, and thus the midamble is filled with random data bits.

In some test scenarios an AWGN signal is added to the interferers. The AWGN signal power is measured over a bandwidth of 270,833 kHz.

Power ramping according to the requirements in Annex B shall be applied to all delayed interferers. The other interferers shall be random and continuous modulated signals.

NOTE: The non-delayed interferer is the same signal for which reference interference performance requirements normally apply (see clause 6.3).

In adjacent timeslots of the delayed interferers no power shall be applied. The delay is measured from the same bit position in the wanted signal burst and the interferer burst, where the position in the wanted signal is the reference position.

The C/I1 values in tables 2aa, 2ab and 2ag are ratios of received powers expressed in dB; where C is the received power of the downlink signal using Normal burst for AQPSK (see 3GPP TS 45.002) and I1 is the received power of the dominant external interferer (Co-channel 1 in tables Q.1-1 to Q.1-3) for VDTS-1 to VDTS-3 or the received power of the adjacent channel interferer for VDTS-4 (Adjacent 1 in table Q.1-4).