The Signal-to-Interference-plus-Noise Ratio (SINR), also known as the Signal-to-Noise-plus-Interference Ratio (SNIR), is a fundamental metric used in wireless communication systems. Let’s break it down:
- Definition:
- The SINR/SNIR quantifies the quality of a received signal by comparing the power of the desired signal to the combined interference and background noise.
- It’s analogous to the Signal-to-Noise Ratio (SNR) used in wired communication.
- Mathematically, it’s expressed as:\text{SINR} = \frac{P}{I + N}where:
- (P) is the power of the desired signal.
- (I) is the interference power from other signals.
- (N) represents the background noise power.
- Wireless Networks:
- In wireless networks, signal strength typically decreases with distance due to path loss.
- SINR accounts for additional factors like interference from other simultaneous transmissions.
- It helps assess connection quality and reliability.
- Propagation Models:
- To estimate SINR, we use mathematical models that consider both random and deterministic components of signal propagation.
- Stochastic geometry models are often used for cellular networks.