G.5.3 Test method for PSFCH performance

38.521-43GPPNRPart 4: PerformanceRadio transmission and receptionRelease 17TSUser Equipment (UE) conformance specification

Figure G.5.2-1 descriptively represents the course of a test based in two metrics: the noise-normalized test SNR and the performance session, represented in terms of fractional throughput. The SS counts the re-transmissions samples sent by the UE under test during performance session and calculate the performance metrics based on them. This effectively results on the discard of early re-transmission that might take place between their initialization at State 4-A and the stabilized performance session. The test method is as follows:

1) The UE is set on state 4-A with generic procedure parameters Test Loop Function = On according to TS 38.508-1 [6] clause 4.4A.2. The UE is configured as the transmitting UE.

2) Once the UE is operating on state 4-A, the SNR is set to the test SNR level. This takes place during the test procedure stage. The SS receives and counts every PSCCH/PSSCH sent by the UE under test, then send ACK/NACK/DTX on corresponding PSFCH according to setting in test case.

3) Once the test SNR level is set, the SS shall wait for a stability window of T=10 seconds before recoding the number of sidelink HARQ feedback sent by the UE under test.

4) Upon expiration of the stability window, the SS shall recode the number of re-transmissions sent by the UE under test (Time Point A in Figure G.5.2-1). Then the performance session starts.

5) During the performance session the SS shall record the number of transmitted sidelink HARQ feedback (ACK, NACK and DTX) starting in Time Point A and ending in Time Point B and keep counting the number of re-transmission sent by the UE under test. The performance session lasts for the Test Time defined in sections G.5.6 for PSFCH miss-detection probability, respectively.

6) Once the Test Time is completed the SS shall recode the number of re-transmissions sent by the UE under test (Time Point B in Figure G.5.2-1) and then stop counting. The SS shall use the retrieved counter values at Time Point A and Time Point B, as well as the recorded number of transmitted sidelink HARQ feedbacks (ACK, NACK and DTX) between Time Point A and Time Point B, to calculate the PSFCH probability of miss-detection.

Figure G.5.3-1: Proposed Test Method for PSFCH performance

According to both the test method described in this section and Figure G.5.3-1, the PSFCH probability of miss-detection can be defined as follows when ACK/NACK HARQ or NACK-only HARQ is applied, respectively.

When NACK-only HARQ is applied, the DTX to NACK probability defined in TS 38.101-4 [5] clause 11.1.5.1.1.2 can be defined as follows:

When ACK/NACK HARQ is applied, the success detection probability of ACK can be defined as follows:

And the success detection probability of NACK/DTX can be defined as follows:

Where:

P^MD = Probability of Miss-Detection

P^SD = Probability of success detection

ReTx_ACK = number of re-transmissions corresponding to the ACK sent by the SS.

ReTx_NACK = number of re-transmissions corresponding to the NACK sent by the SS.

ReTx_DTX = number of re-transmissions corresponding to the DTX sent by the SS.

NACK_Counter = number of ACK feedback sent by the SS

NACK_Counter = number of NACK feedback sent by the SS

DTX_Counter = number of PSFCH occasions on which SS chooses to send nothing

T = 10 seconds stability window

MNAS = Minimum Number of Active Subframes, as per Table G.5.6-1 for PSFCH probability of miss-detection.