An Integrated True Zero-Wait-Time Dynamic Frequency Selection (DFS) Look-Ahead Scheme for WiFi-Radar System co-Existence

An integrated look-ahead DFS scheme relies on having a dedicated low-cost receiver that constantly scans the WiFi band for radar existence. A table of radar-occupied WiFi channels is constructed as a result. When it is time to switch channels upon radar in-channel detection, the WiFi transceiver can directly jump to an empty channel without having to sniff for 60s, as required by FCC/ETSI regulations. The scheme results in zero-wait time and zero impact to WiFi throughput. Circuit implementation relies on reusing some readily existing hardware in a 55nm CMOS n×n MIMO WiFi transceiver to reduce die cost.