A wireless local area network (WLAN) device processes received samples for a radio frequency channel in an unlicensed radio frequency band to detect radio frequency interference from a long term evolution (LTE) wireless communication system. The WLAN device performs a correlation of received time-domain samples to detect the presence of a cyclic prefix for an orthogonal frequency division multiplexing (OFDM) symbol used by the LTE wireless communication system. The WLAN device searches for cross-correlation peaks (1) that exceed a peak power threshold value, (2) that a ratio of which exceed a ratio threshold, and (3) that are separated by a time period corresponding to the OFDM symbol. The WLAN device detects the presence of the LTE wireless communication system without decoding the OFDM symbols.