Wireless signal transmission systems, methods and apparatus
First Claim
1. A local wireless audio signal transmission system for transmitting audio signals within a local signal transmission area, comprising:
- local radio transmitter means for transmitting the audio signals wirelessly within the local signal transmission area in the form of frequency modulated radio signals within a first, relatively high frequency band; and
wireless receiver means for receiving the frequency modulated radio signals for reproducing the audio signals therefrom, the wireless receiver means comprising;
an antenna for receiving the locally transmitted frequency modulated radio signals;
a fixed frequency downconverter coupled with the antenna to receive the locally transmitted frequency modulated radio signals therefrom and operative to downconvert the received frequency modulated radio signals to a second frequency band including signal frequencies lower than signal frequencies included in the first, relatively high frequency band, said second frequency band being an FM frequency band which when supplied to an FM radio produces said audio signals therefrom; and
frequency modulation receiver means in said FM radio connected to said downconverter to receive the downconverted frequency modulated radio signals and reproduce the audio signals therefrom.
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Accused Products
Abstract
Systems, methods and apparatus are provided for conducting local wireless audio signal transmissions from a local audio signal source to a person within a local signal transmission area. In certain embodiments, the transmissions are conducted over the 900 MHz local transmission band to a portable receiver unit supported on the headband of a stereo headphone unit. The receiver unit serves to down convert the 900 MHz signal to a local frequency band which is received by an FM receiver of the receiver unit which serves to reproduce the audio signals therefrom which are, in turn, converted to acoustic signals by electroacoustic transducers of the headphone. A transmitter unit includes a ceramic resonator stabilized FM transmitter, as well a filter for suppressing high frequency noise in an audio modulation signal, a stereo audio multiplexing unit utilizing a 3fH subcarrier and an overmodulation detection unit. In certain embodiments, the receiver unit is powered by a rechargeable battery which is recharged from the transmitter unit.
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Citations
29 Claims
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1. A local wireless audio signal transmission system for transmitting audio signals within a local signal transmission area, comprising:
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local radio transmitter means for transmitting the audio signals wirelessly within the local signal transmission area in the form of frequency modulated radio signals within a first, relatively high frequency band; and wireless receiver means for receiving the frequency modulated radio signals for reproducing the audio signals therefrom, the wireless receiver means comprising; an antenna for receiving the locally transmitted frequency modulated radio signals; a fixed frequency downconverter coupled with the antenna to receive the locally transmitted frequency modulated radio signals therefrom and operative to downconvert the received frequency modulated radio signals to a second frequency band including signal frequencies lower than signal frequencies included in the first, relatively high frequency band, said second frequency band being an FM frequency band which when supplied to an FM radio produces said audio signals therefrom; and frequency modulation receiver means in said FM radio connected to said downconverter to receive the downconverted frequency modulated radio signals and reproduce the audio signals therefrom. - View Dependent Claims (2, 3, 4, 5, 6, 7, 20, 27)
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8. A wireless receiver unit for receiving locally transmitted frequency modulated audio signals produced by a local wireless audio signal transmitter, the locally transmitted signals being produced within a first, relatively high frequency band, comprising:
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an antenna for receiving the locally transmitted signals; a fixed frequency downconverter coupled with the antenna to receive the locally transmitted frequency modulated audio signals therefrom and operative to downconvert the received locally transmitted frequency modulated audio signals to a second frequency band including signal frequencies lower than signal frequencies included in the first, relatively high frequency band of the received locally transmitted frequency modulated audio signals, said second frequency band being an FM frequency band which when supplied to an FM radio produces audio signals therefrom; and frequency modulation receiver means in said FM radio connected to said downconverter to receive the downconverted frequency modulated radio signals and reproduce the audio signals therefrom. - View Dependent Claims (9, 10, 11, 12, 13, 14, 23, 28)
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15. A local wireless audio signal transmission system for transmitting audio signals within a local signal transmission area, comprising:
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local radio transmitter means for transmitting the audio signals wirelessly within the local signal transmission area in the form of modulated radio signals at a first relatively high frequency band, the local radio transmitter means including input means for receiving the audio signals, low pass filter means for attenuating noise in the received audio signals above a predetermined frequency value, and means for producing radio frequency transmission signals modulated by the filtered audio signals; and radio receiver means for receiving the modulated radio frequency transmission signals, said radio receiver means comprising a fixed frequency downconverter to downconvert the modulated radio signals in said first frequency band to a second frequency band, said radio receiver means being tunable to a frequency band within said second frequency band but being outside the range of 88-108 MHz, said second frequency band producing said audio signals when supplied to an FM radio, said radio receiver means further comprising means for demodulating the received signals to reproduce the filtered audio signals and electroacoustic transducer means for converting the filtered audio signals to signals audible by a user. - View Dependent Claims (16, 17, 18, 19, 29)
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21. A local wireless audio signal transmission system for transmitting audio signals within a local signal transmission area, comprising:
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local radio transmitter means for transmitting the audio signals wirelessly within the local signal transmission area in the form of frequency modulated radio signals within a first, relatively high frequency band; and wireless receiver means for receiving the frequency modulated radio signals for reproducing the audio signals therefrom, the wireless receiver means comprising; an antenna for receiving the locally transmitted frequency modulated radio signals; a fixed frequency downconverter coupled with the antenna to receive the locally transmitted frequency modulated radio signals therefrom and operative to downconvert the received frequency modulated radio signals to a second frequency band including signal frequencies lower than signal frequencies included in the first, relatively high frequency band, said second frequency band being an FM frequency band which when supplied to an FM radio produces audio signals therefrom; and a frequency modulation integrated circuit receiver having an input connected to the downconverter to receive the downconverted frequency modulated radio signals and operative to reproduce the audio signals therefrom. - View Dependent Claims (22)
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24. A wireless receiver unit for receiving locally transmitted frequency modulated audio signals produced by a local wireless audio signal transmitter, the locally transmitted signals being produced within a first, relatively high frequency band, comprising:
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an antenna for receiving the locally transmitted signals; a fixed frequency downconverter coupled with the antenna to receive the locally transmitted frequency modulated audio signals therefrom and operative to downconvert the received locally transmitted frequency modulated audio signals to a second frequency band including signal frequencies lower than signal frequencies included in the first, relatively high frequency band of the received locally transmitted frequency modulated audio signals; and a frequency modulation integrated circuit receiver having an input connected to the downconverter to receive the downconverted frequency modulated audio signals and operative to reproduce the audio signals therefrom, said second frequency band being an FM frequency band which when supplied to an FM radio produces audio signals therefrom. - View Dependent Claims (25, 26)
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Specification