Patent ID: 7369836
Filing Date: 2008-05-06
Classification: H04B

Abstract:
1. An adjacent interference removal device for removing an influence of an adjacent interference caused by an interference signal contained in an IF signal having passed through an IF filter having a pass frequency band width with the carrier frequency as its center, said device comprising: a first narrow band filter which inputs into itself the IF signal and has a pass frequency band width extending from the carrier frequency of the IF filter to a predetermined frequency higher than an upper side closest adjacent channel carrier frequency; a second narrow band filter which inputs into itself the IF signal and has a pass frequency band width extending from the carrier frequency of the IF filter to a predetermined frequency lower than a lowe side closest adjacent channel carrier frequency; first detecting means for detecting a first signal having passed through the first narrow band filter; second detecting means for detecting a second signal having passed through the second narrow band filter; signal selecting means for outputting at least a first detection signal outputted from the first detecting means or a second detection signal outputted from the second detecting means; identifying means for identifying whether an interference signal is contained in the first signal or contained in the second signal; and control means which allows the signal selecting means to output the first detection signal when the identifying means identifies that the interference signal is contained in the first signal but not in the second signal, and allows the signal selecting means to output the second detection signal when the identifying means identifies that the interference signal is contained in the second signal but not in the first signal; main detecting means for supplying a main detection signal generated by detecting the IF signal to the signal selecting means; a narrow band pass filter that inputs into itself the IF signal and has a narrow pass frequency band width coincident with the carrier frequency of an adjacent channel; and adjacent station detecting means that detects whether an interference signal is contained in an output signal of the narrow band pass filter, and allows the signal selecting means to output the first or second detection signal when an interference signal is detected, but allows the signal selecting means to putout the main detection signal when the interference signal is not detected.