8.5 Performance requirements for Narrowband IoT
36.1043GPPBase Station (BS) radio transmission and receptionEvolved Universal Terrestrial Radio Access (E-UTRA)Release 18TS
8.5.1 Requirements for NPUSCH format 1
8.5.1.1 Requirements
The performance requirement of NPUSCH format 1 is determined by a minimum required throughput for a given SNR. The required throughput is expressed as a fraction of maximum throughput for the FRCs listed in Annex A16. The performance requirements assume HARQ retransmissions.
An NB-IoT Base Station supports 15 kHz subcarrier spacing requirements, or 3.75 kHz subcarrier spacing requirements, or both.
For 15kHz subcarrier spacing single-subcarrier/multi-subcarrier, the demodulation requirements apply for the supported number of subcarriers.
Table 8.5.1.1-1: Test parameters
|
Parameter |
Value |
|
Maximum number of HARQ transmissions |
4 |
|
RV sequence |
RV0, RV2 |
8.5.1.1.1 Minimum requirements
The throughput shall be equal to or larger than the fraction of maximum throughput stated in table 8.5.1.1.1-1 for the single-subcarrier of 3.75KHz subcarrier spacing, in table 8.5.1.1.1-2 for 15KHz subcarrier spacing at the given SNR for 1Tx, and in table 8.5.1.1.1-3 for multi-subcarrier of 15KHz subcarrier spacing at the given SNR for 1Tx.
Table 8.5.1.1.1-1: Minimum requirements for NPUSCH format 1, 200KHz Channel Bandwidth, 3.75KHz subcarrier spacing, 1Tx
|
Number of TX antennas |
Number of RX antennas |
Subcarrier spacing |
Number of allocated subcarriers |
Propagation conditions and correlation matrix (Annex B) |
FRC |
Repetition number |
Fraction of maximum throughput |
SNR [dB] |
|
1 |
2 |
3.75KHz |
1 |
ETU 1Hz Low |
A16-1 |
1 |
70% |
-1.9 |
|
16 |
70% |
-9.2 |
||||||
|
64 |
70% |
-12.2 |
Table 8.5.1.1.1-2: Minimum requirements for NPUSCH format 1, 200KHz Channel Bandwidth, 15KHz subcarrier spacing, single subcarrier, 1Tx
|
Number of TX antennas |
Number of RX antennas |
Subcarrier spacing |
Number of allocated subcarriers |
Propagation conditions and correlation matrix (Annex B) |
FRC |
Repetition number |
Fraction of maximum throughput |
SNR [dB] |
|
1 |
2 |
15KHz |
1 |
ETU 1Hz Low |
A16-2 |
1 |
70% |
-2.1 |
|
16 |
70% |
-8.8 |
||||||
|
64 |
70% |
-12.6 |
Table 8.5.1.1.1-3: Minimum requirements for NPUSCH format 1, 200KHz Channel Bandwidth, 15KHz subcarrier spacing, multiple subcarriers, 1Tx
|
Number of TX antennas |
Number of RX antennas |
Subcarrier spacing |
Number of allocated subcarriers |
Propagation conditions and correlation matrix (Annex B) |
FRC |
Repetition number |
Fraction of maximum throughput |
SNR [dB] |
|
1 |
2 |
15KHz |
3 |
ETU 1Hz Low |
A16-3 |
2 |
70% |
-3.0 |
|
16 |
70% |
-8.1 |
||||||
|
64 |
70% |
-11.4 |
||||||
|
6 |
ETU 1Hz Low |
A16-4 |
2 |
70% |
-0.6 |
|||
|
16 |
70% |
-6.8 |
||||||
|
64 |
70% |
-10.5 |
||||||
|
12 |
ETU 1Hz Low |
A16-5 |
2 |
70% |
-0.7 |
|||
|
16 |
70% |
-6.4 |
||||||
|
64 |
70% |
-10.1 |
Table 8.5.1.1.1-4: Minimum requirements for NPUSCH format 1 with two HARQ processes and multiple TBs with interleaved transmission
|
Number of TX antennas |
Number of RX antennas |
Subcarrier spacing |
Number of allocated subcarriers |
Propagation conditions and correlation matrix (Annex B) |
FRC |
Repetition number |
Fraction of maximum throughput |
SNR [dB] |
|
1 |
2 |
15KHz |
12 |
ETU 1Hz Low |
A16-6 |
64 |
70% |
-13.9 |
Table 8.5.1.1.1-5: Minimum requirements for NPUSCH format 1 with 16QAM, single TB scheduling
|
Number of TX antennas |
Number of RX antennas |
Subcarrier spacing |
Number of allocated subcarriers |
Propagation conditions and correlation matrix (Annex B) |
FRC |
Repetition number |
Fraction of maximum throughput |
SNR [dB] |
|
1 |
2 |
15KHz |
12 |
ETU 1Hz Low |
A16-7 |
64 |
70% |
9.1 |
8.5.2 Performance requirements for NPUSCH format 2
8.5.2.1 DTX to ACK performance
The DTX to ACK probability for NPUSCH format 2 case denotes the probability that ACK is detected when nothing is sent on the wanted signal and only the noise is present per NPUSCH format 2 transmission.
An NB-IoT Base Station supports 15 KHz sub-carrier spacing requirements, or 3.75 KHz sub-carrier spacing requirements, or both.
8.5.2.1.1 Minimum requirement
The DTX to ACK probability, i.e. the probability that ACK is detected when nothing was sent, shall not exceed 1% per NPUSCH format 2 transmission. Where the performance measure definition is as follows:
where:
– #(false ACK bits) denotes the number of detected ACK bits.
– #(ACK/NACK bits) denotes the number of HARQ-ACK information bit per NPUSCH format 2 transmission.
– #( NPUSCH format 2 DTX) denotes the number of DTX occasions.
8.5.2.2 ACK missed detection requirements
The ACK missed detection probability is the probability of not detecting an ACK when an ACK was sent per NPUSCH format 2 transmission.
8.5.2.2.1 Minimum requirements
The ACK missed detection probability shall not exceed 1% at the SNR given in table 8.5.2.2.1-1 and table 8.5.2.2.1-2 for 1Tx case.
Table 8.5.2.2.1-1: Minimum requirements for NPUSCH format 2, 200KHz Channel Bandwidth, 3.75KHz subcarrier spacing, 1Tx
|
Number of TX antennas |
Number of RX antennas |
Propagation conditions and correlation matrix (Annex B) |
Number of allocated subcarriers |
Subcarrier spacing |
Repetition number |
SNR [dB] |
|
1 |
2 |
EPA 5 Low |
1 |
3.75KHz |
1 |
7.0 |
|
16 |
-5.3 |
|||||
|
64 |
-10.9 |
Table 8.5.2.2.1-2: Minimum requirements for NPUSCH format 2, 200KHz Channel Bandwidth, 15KHz subcarrier spacing, 1Tx
|
Number of TX antennas |
Number of RX antennas |
Propagation conditions and correlation matrix (Annex B) |
Number of allocated subcarriers |
Subcarrier spacing |
Repetition number |
SNR [dB] |
|
1 |
2 |
EPA 5 Low |
1 |
15KHz |
1 |
6.3 |
|
16 |
-3.9 |
|||||
|
64 |
-9.5 |
8.5.3 Performance requirements for NPRACH
8.5.3.1 NPRACH False alarm probability
The false alarm requirement is valid for any number of receive antennas, for all repetition numbers and for any number of subcarriers.
The false alarm probability is the conditional total probability of erroneous detection of the preamble (i.e. erroneous detection from any detector) when input is only noise.
8.5.3.1.1 Minimum requirement
The false alarm probability shall be less than or equal to 0.1%.
8.5.3.2 NPRACH detection requirements
The probability of detection is the conditional probability of correct detection of the preamble when the signal is present. There are several error cases – detecting different preamble than the one that was sent, not detecting a preamble at all or correct preamble detection but with the wrong timing estimation. A timing estimation error occurs if the estimation error of the timing of the strongest path is larger than 3.646us. The strongest path for the timing estimation error refers to the strongest path in the power delay profile.
The requirements for TDD are optional and only valid for base stations supporting TDD.
Table 8.5.3.2-1: Test preambles for NPRACH
|
Parameter |
Value |
|
Narrowband physical layer cell identity |
0 |
|
Initial subcarrier index |
0 |
|
Uplink-downlink configuration for TDD |
1 |
|
Special subframe configuration for TDD |
7 |
8.5.3.2.1 Minimum requirements
The probability of detection shall be equal to or exceed 99% for the SNR levels listed in table 8.5.3.2.1-1.
Table 8.5.3.2.1-1: NPRACH missed detection requirements for FDD
|
Number of TX antennas |
Number of RX antennas |
Repetition number |
Propagation conditions and correlation matrix (Annex B) |
Frequency offset |
SNR[dB] |
||
|
Preamble format 0 |
Preamble format 1 |
Preamble format 2 |
|||||
|
1 |
2 |
8 |
AWGN |
0 |
-2.1 |
-2.1 |
-1.0 |
|
EPA1 Low |
200 Hz |
6.1 |
6.1 |
9.0 |
|||
|
32 |
AWGN |
0 |
-6.8 |
-6.8 |
-5.1 |
||
|
EPA1 Low |
200 Hz |
0.5 |
0.5 |
2.2 |
|||
Table 8.5.3.2.1-2: NPRACH missed detection requirements for TDD
|
Number of TX antennas |
Number of RX antennas |
Repetition number |
Propagation conditions and correlation matrix (Annex B) |
Frequency offset |
SNR[dB] |
|||
|
Preamble format 0 |
Preamble format 1 |
Preamble format 0-a |
Preamble format 1-a |
|||||
|
1 |
2 |
8 |
AWGN |
0 |
5.6 |
2.5 |
4.0 |
1.0 |
|
EPA1 Low |
200 Hz |
14.7 |
10.1 |
13.7 |
9.0 |
|||
|
32 |
AWGN |
0 |
0.9 |
-2.2 |
-0.7 |
-3.6 |
||
|
EPA1 Low |
200 Hz |
9.8 |
4.3 |
10.0 |
2.5 |
|||