摘要 |
AN ECHO AND NOISE SUPPRESSION DEVICE FOR PROCESSING AN INFORMATION SIGNAL TO SUPPRESS UNWANTED SIGNAL COMPONENTS. IN AN EXEMPLARY EMBODIMENT, THE ECHO SUPPRESSION DEVICE INCLUDES AN AC-CENTER CLIPPER (40) HAVING A CLIPPING WINDOW WITH AN ADJUSTABLE WINDOW CENTER. A CLIPPING THRESHOLD OF THE AC-CENTER CLIPPER IS SET TO ATTENUATE THE UNWANTED SIGNAL COMPONENTS, AND THE CENTER OF THE CLIPPING WINDOW IS VARIED IN ACCORDANCE WITH THE VALUE OF THE INFORMATION SIGNAL SO THAT THE UNWANTED COMPONENTS ARE SUPPRESSED EVEN WHEN THE INFORMATION SIGNAL CONTAINS A SIGNIFICANT NOISE COMPONENT. IN ANOTHER EXEMPLARY EMBODIMENT, A MOBILE RADIO STATION IS PROVIDED INCLUDING A MICROPHONE (10) FOR RECEIVING A NEAR-END AUDIO INPUT AND FOR PRODUCING A NEAR-END AUDIO OUTPUT WHICH IS TO BE TRANSMITTED TO A FAR-END USER. THE EXEMPLARY MOBILE STATION ALSO INCLUDES A LOUDSPEAKER (20) FOR BROADCASTING, TO A NEAR-END USER OF THE MOBILE STATION, A FAR-END AUDIO SIGNAL WHICH IS GENERATED BY THE FAR-END USER AND THEN RECEIVED AT THE MOBILE STATION. AN ECHO SUPPRESSION CIRCUIT WITHIN THE MOBILE STATION IS USED TO ATTENUATE AN ECHO COMPONENT OF THE NEAR-END AUDIO SIGNAL WHICH RESULTS FROM THE MOBILE STATION MICROPHONE RECEIVING OUTPUT FROM THE MOBILE STATION LOUDSPEAKER. THE ECHOSUPPRESSION CIRCUIT INCLUDES AN AC-CENTER CLIPPER (40) HAVING A CLIPPING WINDOW WITH AN ADJUSTABLE CLIPPING CENTER.FIGURE 5
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