A matched filter is a signal processing technique that maximizes the signal-to-noise ratio (SNR) of a received signal by correlating it with a known reference template, effectively "matching" the filter's impulse response to the expected signal waveform. In WiFi CSI sensing, matched filtering is applied to enhance the detectability of weak or overlapping channel response patterns associated with specific activities or physical states, making it particularly valuable for energy-efficient sensing scenarios where transmitted power is limited and clean signal extraction is critical. Key variants include time-domain matched filtering applied to CSI amplitude or phase sequences and compressed or adaptive versions that reduce computational overhead for lightweight deployment on resource-constrained sensing nodes.
Source Papers
- A Survey on Green Wireless Sensing: Energy-Efficient Sensing via WiFi CSI and Lightweight Learning ↗ — A Survey on Green Wireless Sensing: Energy-Efficient Sensing
- A low-cost automatic people-counting system at bus stops using Wi-Fi probe requests and deep learning ↗ — A low-cost automatic people-counting system at bus stops usi