Patent ID: 6178317
Filing Date: 2001-01-23
Classification: H04B,H04H,H04L

Abstract:
A system for mitigating intermittent interruptions in an audio radio broadcast system, comprising:a source of an audio signal;transmitter means having a first input coupled to said audio source for modulating at least one first carrier signal with said audio signal to broadcast a primary radio signal;first delay means having an input coupled to said audio source for adding a first predetermined time delay to said audio signal to form a delayed redundant audio signal at an output thereof, said output being coupled to a second input of said transmitter means for modulating at least one second carrier signal with said delayed redundant audio signal to broadcast a delayed redundant radio signal simultaneously with said primary radio signal;receiver means for receiving said primary radio signal and said delayed redundant radio signal, said receiver means demodulating said primary radio signal to provide said audio signal to a first output thereof and demodulating said delayed redundant radio signal to provide said delayed redundant audio signal to a second output thereof, said receiver means including means for detecting degradation of said received primary radio signal, said means for degradation detection providing a quality measurement signal to a third output of said receiver means;second delay means having an input coupled to said first output of said receiver means for adding a second predetermined time delay to said audio signal to form a delayed primary audio signal at an output thereof, said second predetermined time delay being substantially equal to said first predetermined time delay;blending means having a first input coupled to an output of said second delay means and second and third inputs respectively coupled to said second and third outputs of said receiver means for combining a first weighting factor with said delayed primary audio signal and a second weighting factor with said delayed redundant audio signal and combining said weighted delayed primary audio signal with said weighted delayed redundant audio signal to form a composite audio signal, said first weighting factor being smoothly transitioned between a first value and a second value responsive to said quality measurement signal being less than a predetermined threshold value, said second weighting factor being smoothly transitioned between said second value and said first value responsive to said quality measurement signal being less than said predetermined threshold value; andaudio output means coupled to said blending means for converting said composite audio signal to an aural signal.