Signal to interference plus noise ratio

SINR is the ratio of the received signal level and the sum of interference and noise. The 3GPP specification does not include the SINR parameter. UE (user equipment) does not send the results back to the network. SINR is measured and used only in UE. It is used to better express the ralitionship between radio conditions and throughput. For example it can be used for calculating CQI value. Specific implementations may vary and it is up to the manufacturer to decide, how to implement this measurement. This is making difficult to compare results of different devices. SINR is also measured in UMTS and 5G NR

CQI (Channel Quality Indication) - Instead of expressing the CQI as a received signal quality, the CQI expressed as a data rate that terminal (UE) can support under the actual radio conditions. SINR is used for calculating CQI. In LTE, CQI has only 15 codes. MCS parameter is assigned based on the CQI value. CQI can be increased if the BLER value is under 10%.

SINR and CQI calculation


SINR and CQI mapping table in LTE

SINR [dB] CQI code Modulation Code Rate Spectral efficiency
-6.7 1 QPSK 0.076 0.15
-4.7 2 QPSK 0.12 0.23
-2.3 3 QPSK 0.19 0.38
0.2 4 QPSK 0.3 0.60
2.4 5 QPSK 0.44 0.88
4.3 6 QPSK 0.59 1.18
5.9 7 16QAM 0.37 1.48
8.1 8 16QAM 0.48 1.91
10.3 9 16QAM 0.6 2.41
11.7 10 64QAM 0.45 2.73
14.1 11 64QAM 0.55 3.32
16.3 12 64QAM 0.65 3.90
18.7 13 64QAM 0.75 4.52
21.0 14 64QAM 0.85 5.12
22.7 15 64QAM 0.93 5.55
CQI
Ilustration of MCS assignment

Source: GHOSH, Amitabha a Rapeepat RATASUK. Essentials of LTE and LTE-A.

Please enter the values in the required format.

Please fill in all the required fields.