摘要 |
A method (200) and system (300) for detecting temporarily available bandwidth in a frequency band: select (205) a channel in the frequency band; measure (210) an energy received in the selected channel; compare (215) the measured energy to a first threshold; when the measured energy exceeds the first threshold, determine that the channel is unavailable (220) for transmission, otherwise determine (225) that the channel is available for transmission; correlate (255) a signal received in the channel with a known feature of a signal conforming to a particular transmission format; compare (260) the correlation result to a second threshold; when the correlation result in the channel exceeds the second threshold, determine (265) that a signal conforming to the particular transmission format is present in the channel, otherwise determine (270) that the signal conforming to the particular transmission format is not present in the channel. |