Abstract: The present invention is directed to a method for use in a cognitive radio. A Fourier transform of a time domain signal is performed to obtain a series of frequency domain samples covering substantially the entire predetermined RF spectrum, the time domain signal corresponding to the RF waveform, each frequency domain sample being characterized by a predetermined waveform characteristic. The predetermined waveform characteristic of each frequency domain sample is evaluated in each subcarrier block to obtain a subcarrier block activity level for each subcarrier block. A subcarrier block is selected when its subcarrier block activity level is greater than a predetermined threshold.

Abstract: Methods and systems for injecting a wireless message in a cellular communication system. The attacking system receives a synchronization waveform from a base station and synchronizes in time and frequency. The attacking system transmits the correct time and frequency, and also transmits one or more attack messages. The mobile transceiver receives the one or more attack messages and responds. The attacking system then transmits a first wireless message configured to alter a characteristic of a physical layer of the mobile station.

Abstract: The present invention is directed to a method for use in a cognitive radio. A Fourier transform of a time domain signal is performed to obtain a series of frequency domain samples covering substantially the entire predetermined RF spectrum, the time domain signal corresponding to the RF waveform, each frequency domain sample being characterized by a predetermined waveform characteristic. The predetermined waveform characteristic of each frequency domain sample is evaluated in each subcarrier block to obtain a subcarrier block activity level for each subcarrier block. A subcarrier block is selected when its subcarrier block activity level is greater than a predetermined threshold.