Patent ID: 8275323

Claim:
A system, comprising: an activity sensing module configured to sense radio frequency (RF) activity in a first sub-channel and a second sub-channel of a communication channel of a first wireless network, and generate control signals based on the RF activity sensed in at least one of the first sub-channel and the second sub-channel, wherein the activity sensing module includes N adjacent channel interference (ACI) filter modules, wherein the N ACI filter modules are arranged in parallel and are configured to receive signals from N antennas, respectively, filter out signals in channels adjacent to the communication channel, and generate N filtered signals, respectively, where N is an integer greater than 2, and wherein the activity sensing module is configured to generate the control signals based on the N filtered signals; and a channel identification module configured to process the control signals, determine that both of the first sub-channel and the second sub-channel are available for communication in response to the RF activity originating from a second wireless network being not present in both of the first sub-channel and the second sub-channel, and determine that the first sub-channel is available for communication in response to the RF activity originating from the second wireless network being present only in the second sub-channel and being less than or equal to a predetermined threshold, wherein the second wireless network is different than the first wireless network.