SINR → CQI → MCS Throughput Calculator
Map SINR (dB) to CQI, modulation, code rate and estimated peak throughput for LTE and 5G NR per 3GPP TS 36.213 / TS 38.214.
Technology
| CQI Index | 8 |
| Modulation | 16QAM |
| Code Rate (×1024) | 490 |
| Spectral Efficiency | 1.9141 bps/Hz |
| PRBs | 50 (10 MHz) |
| MIMO Layers | 1 |
| Overhead | 14% |
| Peak Throughput | 27.65 Mbps |
Shannon bound at +10 dB: C = B · log₂(1 + 10^(10/10)) ≈ 3.46 bps/Hz theoretical max
CQI Table — 3GPP TS 36.213 Table 7.2.3-1
| CQI | Modulation | Code Rate ×1024 | SE (bps/Hz) | SINR ≥ (dB) |
|---|---|---|---|---|
| 0 | — | — | 0 | < −6.7 |
| 1 | QPSK | 78 | 0.1523 | -6.7 |
| 2 | QPSK | 120 | 0.2344 | -4.7 |
| 3 | QPSK | 193 | 0.3770 | -2.3 |
| 4 | QPSK | 308 | 0.6016 | +0.2 |
| 5 | QPSK | 449 | 0.8770 | +2.4 |
| 6 | QPSK | 602 | 1.1758 | +4.3 |
| 7 | 16QAM | 378 | 1.4766 | +5.9 |
| 8◀ | 16QAM | 490 | 1.9141 | +8.1 |
| 9 | 16QAM | 616 | 2.4063 | +10.3 |
| 10 | 64QAM | 466 | 2.7305 | +11.7 |
| 11 | 64QAM | 567 | 3.3223 | +14.1 |
| 12 | 64QAM | 666 | 3.9023 | +16.3 |
| 13 | 64QAM | 772 | 4.5234 | +18.7 |
| 14 | 64QAM | 873 | 5.1152 | +21 |
| 15 | 64QAM | 948 | 5.5547 | +22.7 |
Reference — Formulas & Modulation
Shannon capacity: C = B · log₂(1 + SINR)
Peak Throughput (Mbps) = PRBs × 12 × 14 × slots/ms × SE × layers × (1 − overhead) / 1000
LTE: 2 slots/ms · NR SCS 30 kHz: 4 slots/ms
The Shannon bound gives the theoretical maximum; practical LTE/NR systems achieve roughly 70–80% of the Shannon limit due to coding overhead, pilot signals, and guard intervals. The spectral efficiency calculator lets you compare across 2G/3G/4G/5G. Measured RSRP/RSRQ values from a drive test can be converted to an approximate SINR as a starting point. PRB counts for each bandwidth option are listed in the PRB calculator.
| Modulation | Bits/symbol | Typical SINR | Notes |
|---|---|---|---|
| QPSK | 2 | < 6 dB | LTE + NR, robust, low throughput |
| 16QAM | 4 | 6–11 dB | LTE + NR, moderate quality |
| 64QAM | 6 | 11–23 dB | LTE + NR, good quality |
| 256QAM | 8 | > 23 dB | 5G NR only (TS 38.214), indoor/small cell |
| 1024QAM | 10 | > 30 dB | Future / proprietary mmWave |
Note: the SINR → CQI mapping shown is typical/average per 3GPP. Actual mapping varies by UE vendor implementation, receiver algorithm, and network configuration. Operators may shift thresholds by ±1–2 dB.
Frequently Asked Questions
What is CQI and how is it reported?▾
CQI (Channel Quality Indicator) is a 4-bit value (0–15) reported by the UE to the eNB/gNB to indicate the downlink channel quality. A CQI of 0 means the channel quality is too poor for any transmission. CQI 1–15 correspond to specific modulation and coding scheme (MCS) combinations defined in 3GPP TS 36.213 (LTE) and TS 38.214 (5G NR). The UE derives CQI from the measured SINR and reports it every few milliseconds via the PUCCH or PUSCH.
What is the relationship between SINR and throughput?▾
SINR determines the maximum modulation order and code rate the receiver can use reliably. Low SINR forces QPSK with low code rate (robust but slow). High SINR allows 64QAM or 256QAM with high code rate (fast). Throughput scales roughly as: bps = PRBs × spectral_efficiency × bandwidth_per_PRB × MIMO_layers × (1 − overhead). A 10 dB improvement in SINR can more than double throughput by enabling a higher MCS.
What is 256QAM in 5G NR and when is it used?▾
256QAM (8 bits per symbol) is supported in 5G NR for both downlink and uplink, providing ~33% more throughput than 64QAM (6 bits/symbol) when SINR is sufficiently high (typically > 25 dB sustained). It requires very high signal quality and low interference, making it most practical for indoor deployments, small cells, or UEs close to a gNB. 3GPP TS 38.214 Table 5.2.2.1-3 defines the 256QAM CQI table.
How many MIMO layers can LTE and 5G NR support?▾
LTE supports up to 4 spatial layers (4×4 MIMO) per carrier per TS 36.213. 5G NR supports up to 8 layers for downlink massive MIMO (TS 38.214). Each layer carries an independent data stream, multiplying peak throughput by the layer count — provided the propagation channel has sufficient spatial diversity. Practical layer counts depend on antenna configuration (2T2R, 4T4R, 8T8R, 32T32R, 64T64R) and UE capability.