13.17.1c Phase and amplitude coherency in EC-GSM-IoT Configuration

3GPP51.010-1Mobile Station (MS) conformance specificationPart 1: Conformance specificationTS

13.17.1c.1 Definition

Phase and amplitude coherency is required for blind physical layer transmissions, used for higher Coverage Classes in EC-GSM-IoT configuration. It is achieved by repeating a Tx burst in subsequent timeslots in a TDMA frame with the same amplitude and phase. No coherency of blind physical layer transmissions between TDMA frames is required.

13.17.1c.2 Conformance requirement

The normalized coherency error () as defined in 3GPP TS 45.005[50], Annex S, between any two bursts of the blind physical layer transmissions transmitted over consecutive timeslots in Coverage Class CC2, CC3 or CC4 shall not exceed -23 dB at received signal levels from the maximum applicable level for NER, specified for static conditions at a bit error rate of 10-3 in 3GPP TS 45.005 [50] subclause 6.1.1.2, down to the reference sensitivity level of EC-SCH, see 3GPP TS 45.005 table 1aa. The phase and amplitude coherency requirement applies to the 2 TS EC-RACH mapping, EC-PDTCH and EC-PACCH, see 3GPP TS 45.002 [47] for how the bursts of a block for a specific logical channel are mapped onto the physical channel(s). The requirement applies for any given Overlaid CDMA code assigned, see 3GPP TS 44.018 [111].

13.17.1c.3 Test purpose

1. To verify that, in EC-GSM-IoT configuration, phase and amplitude coherency requirements are met when transmitting uplink data on EC-PDTCH for any given Overlaid CDMA code assigned, see 3GPP TS 44.018 [111] and receiving signalling on EC-PACCH/D, both UL and DL using Coverage Class CC4, whereby the normalized coherency error (see definition in subclause 13.7.1c.2) does not exceed -23 dB under normal conditions.

2. To verify that, in EC-GSM-IoT configuration, phase and amplitude coherency requirements are met when transmitting 2 TS EC-RACH and receiving signalling on EC-PCH, both UL and DL using Coverage Class CC4, whereby the normalized coherency error (see definition in subclause 13.7.1c.2) does not exceed -23 dB under normal conditions.

13.17.1c.4 Method of the test

13.17.1c.4.1 Initial conditions

The tests under a) and b) shall use the static radio channel and shall be carried out on BCCH carrier C0 at RF carrier frequency M under normal conditions.

The SS shall command the MS to non-hopping mode.

a) To verify item 1) in subclause 13.7.1c.3, the test shall be run under the use of EC-PDTCH/MCS-1/16, CC4 on uplink, using Overlaid CDMA with 1 selected user of 4, with power control parameter ALPHA (α) set to 0. The MS shall be operated with four uplink slots.

b) To verify item 2) in subclause 13.7.1c.3, the test shall be run under the use of 2 TS EC-RACH/48, CC4. The MS shall be operated with two uplink slots.

The MS shall be commanded to use maximum output power, as specified for the supported band, on all active timeslots throughout the test.

The receive level at the MS is set to -123,5 dBm (minimum input level for EC-BCCH reference performance).

The Test Mode defined in 3GPP TS 44.014 subclause 5.4 shall be utilised.

Mode (a) transmitting pseudo-random data sequence in RLC data blocks;

Specific PICS statements:

– MS without vibration sensitive components (TSPC_No_Vibration_Sensitive_Components)

PIXIT Statements:

13.17.1c.4.2 Procedure

a) To verify item 1) in subclause 13.17.1c.3, following test steps are performed.

a.1) The SS instructs the MS to its maximum power control level by setting the power control parameter ALPHA () to 0 and GAMMA_TN (CH) for each active timeslot to the maximum output power level in the Packet Uplink Assignment message (using FUA for 1 RLC/MAC block transmitted over 80 ms). The same sequence of pseudo-random encrypted bits is used in consecutive four active timeslots TN2, TN3, TN4 and TN5 in a given TDMA frame.

a.2) After sending the Packet Uplink Assignment message, the SS sets the receive level at the MS to -124,5 dBm (EC-SCH reference sensitivity level).

a.3) For each transmitted uplink burst, the SS captures the signal as a series of complex valued samples over the useful part of the burst (including tail bits). These samples shall be taken at the symbol rate (147 or 148 samples).

a.4) The SS then calculates the error vector magnitude over the determined samples between any two bursts out of four consecutive bursts and determines the Normalized Coherency Error as specified in TS 45.005 [50], Annex S.

a.5) After the FUA ends, the SS sends with a delay of at least [500 ms] the next Packet Uplink Assignment message to the MS with FUA of 1 RLC block. In total 50 Packet Uplink Assignment messages are sent with FUA of 1 RLC block and the SS averages the Normalized Coherency Error over all 50 FUAs, as specified in TS 45.005 [50], Annex S.

a.6) The test is repeated with another Overlaid CDMA code assigned, see 3GPP TS 44.018 [111] and using the consecutive four active timeslots TN4, TN5, TN6 and TN7.

b) To verify item 2) in subclause 13.17.1c.3, following test steps are performed.

b.1) The SS, after sending a P-TMSI assignment to the MS, sends a paging request on EC-PCH with a matching P-TMSI in the paging subchannel corresponding to the CC4 paging block.

b.2) After sending the EC Paging Request message, the SS sets the receive level at the MS to -124,5 dBm (EC-SCH reference sensitivity level).

b.3) For each transmitted uplink burst of the EC Packet Channel Request message following the paging request, containing 48 bursts in 24 TDMA frames for CC4, the SS captures the signal as a series of complex valued samples over the useful part of the burst (including tail bits). These samples shall be taken at the symbol rate (88 samples).

b.4) The SS then calculates the error vector magnitude over the determined samples between the two bursts sent in consecutive time slots and determines the Normalized Coherency Error as specified in TS 45.005 [50], Annex S.

b.5) After the EC Packet Channel Request message ends, the SS does not send a matching response and thus enforces the MS to retransmit the EC Packet Channel Request with the maximum number of retransmissions (EC_Max_Retrans parameter sent over EC-BCCH) configured to be 7. In total 8 EC Packet Channel Request messages are sent and the SS averages the Normalized Coherency Error over the corresponding 192 TDMA frames, fulfilling closely the requirement of averaging over 200 TDMA frames as specified in TS 45.005 [50], Annex S.

For the tests under a) and b), the conformance requirement for the Normalized Coherency Error shall be met.