Tunable Band-Reject Filter and Suppression of In-Band Interfering Signals in Mobile Communication

For supporting a more efficient usage of available spectrum by mobile communication in unlicensed bands, a solution for robust and frequency agile receivers is proposed. Interfering signals of increased power level, expected in these bands, get acceptable as they are reduced by a tunable band-reject filter controlled by the digital receiver unit. The interfering signal position gets identified, the filter stopband gets moved on this position, and distortions of the wanted signal get compensated. A performance evaluation is done on a lab set-up based on hardware prototypes and on implemented control algorithms.