Patent ID: 7986739

Claim:
A method, implemented in a communications transceiver, of detecting communications by narrowband communications systems for avoidance of interference with the narrowband communication systems, comprising: receiving a signal in a receive path of the communications transceiver; correlating the received signal with a plurality of different signal patterns stored in a library; determining, based on the correlating, whether the received signal corresponding to a selected frequency has characteristics of a signal expected to be communicated by a narrowband transmission system; marking a center frequency for nulling transmissions corresponding to the selected frequency in response to the determining operation; and adjusting a center frequency for transmissions, via a transmit path of the communications transceiver, in response to the determining operation, such that the center frequency for transmission avoids the marked center frequency, wherein the correlating further comprises performing an autocorrelation of the received signal corresponding to the selected frequency and performing a cross-correlation of the received signal with the signal expected to be communicated by the narrowband transmission system.