Patent ID: 8081561

Claim:
A signal generator for generating signals within a predetermined frequency band of a first communication system, comprising: an inverse Fast Fourier Transform (IFFT) unit for generating an output signal; a filter operatively connected to the IFFT unit, the filter being configured to filter out, from the output signal, interference located at at least one frequency range, wherein the filter comprises a first mixer operatively connected to the IFFT unit, a lowpass (LP) filter operatively connected to the first mixer, and a second mixer operatively connected to the LP filter; the first mixer is configured to down-convert the output signal, which has a certain frequency, to DC (Direct Current); the LP filter is configured to LP filter the down-converted output signal; and the second mixer is configured to up-convert the LP filtered signal to the certain frequency; and a subtractor operatively connected to the IFFT unit and to the filter, the subtractor being configured to subtract the interference from the output signal; wherein the signal generator is configured to at least temporarily disable carrier frequencies within the at least one frequency range, which is located within the predetermined frequency band and which is provided for a second communication system; the filter is controllable based on carrier frequencies allocated in the frequency range by the second communication system.