Method and system for channel scanning in a wireless communications system

1. A method for channel scanning in a wireless communications system, for the identification of one or more narrow-band channels present in a certain frequency band and which can be used for connection between a wireless communications device and a communications network, the method comprising:

applying a FFT function to at least one signal corresponding to a given frequency band during a certain time interval, providing an output signal, and registering a maximum power value provided for each sub-channel of the output signal during the time interval;

analyzing said maximum power values with a processing device so as to detect at least one frequency region having at least one predetermined feature, and

determining at least one channel position, by considering that each of said at least one frequency region having at least one predetermined feature is a guard band of one of said at least one channel.

2. The method for channel scanning of claim 1 , wherein the wireless communications device performs a network connection attempt for at least one channel identified in said frequency band.

3. The method for channel scanning of claim 1 , wherein the frequency band is divided into a plurality of frequency segments and the FFT function is applied to a plurality of input signals, each input signal having a bandwidth corresponding to one of said frequency segments.

4. The method for channel scanning of claim 1 , further comprising normalizing the power values provided by the FFT function to a common reference.

5. The method for channel scanning of claim 1 , wherein, based on said determined guard bands, determining bandwidth and a center frequency for each determined channel position.

6. The method for channel scanning of claim 3 , wherein the FFT function provides the output signal which has a usable bandwidth smaller than the input signal to which said FFT function is applied, and wherein each frequency segment has a bandwidth which is a determined usable bandwidth.

7. The method for channel scanning of claim 1 , the method further comprising classifying each channel bandwidth into one of a predefined bandwidth category set.

8. The method for channel scanning of claim 1 , further comprising, based on said determined channel positions, identifying one channel plan of a plurality of channel plans stored in the wireless communications device.

9. The method for channel scanning of claim 1 , further comprising, based on said determined channel positions, identifying a channel pattern corresponding to a specific geographical region.

10. The method for channel scanning of claim 1 , wherein the time interval is a WiMAX frame interval.

11. The method for channel scanning of claim 1 , wherein the time interval is a WiMAX frame interval, and wherein for each channel used to attempt to connect with the network, correlating the FFT output for each symbol of the input signal to a power pattern corresponding to the WiMAX frame, and using said correlation to estimate the preamble location of the WiMAX frame.

12. The method for channel scanning of claim 1 , wherein the time interval is a WiMAX frame interval, and wherein for each channel used to attempt to connect with the network, correlating the FFT output for each symbol of the input signal to a power pattern corresponding to the WiMAX frame, and using said correlation to estimate the preamble location of the WiMAX frame, and wherein said correlation is used for determining if the channel supports a WiMAX wireless communications standard.

13. A non-transitory computer readable medium comprising a program product stored thereon and executable by a processor, the program product comprising program instructions for implementing a method for channel scanning in a wireless communications system, for the identification of one or more narrow-band channels present in a certain frequency band and which can be used for connection between a wireless communications device and a communications network, wherein the program instructions comprise:

instructions configured to apply a FFT function to at least one signal corresponding to a given frequency band during a certain time interval, providing an output signal, and registering a maximum power value provided for each sub-channel of the output signal during the time interval;

instructions configured to analyze said power values so as to detect at least one frequency region having at least one predetermined feature, and

instructions configured to determine at least one channel position, by considering that each of said at least one frequency region having at least one predetermined feature is a guard band of one of said at least one channel.

14. A wireless communications device comprising:

means adapted for identification of one or more narrow-band channels present in a certain frequency band and which can be used for connection between a wireless communications device and a communications network and comprising means adapted for:

applying a FFT function to at least one signal corresponding to a given frequency band during a certain time interval, providing an output signal, and registering a maximum power value provided for each sub-channel of the output signal during the time interval, and

analyzing said power values so as to detect at least one frequency region having at least one predetermined feature; and

means adapted for determining at least one channel position, by considering that each of said at least one frequency region having at least one predetermined feature is a guard band of one of said at least one channel.