Transmission of data by ultrasound
First Claim
1. A method for transmitting voice data between a head part and a base part of a hands-free telephone, which comprises:
- compressing information, being the voice data, to be transmitted using compression coding;
digitizing the compressed information;
spreading the digitized information over a wider frequency band using a CDMA technique;
performing a digital to analog conversion on the spread digitized information;
converting the digital to analog converted spread information into an ultrasound signal;
transmitting the ultrasound signal via an air interface;
at a receiver component, receiving the transmitted ultrasound signal and converting the received ultrasonic signal into an analog electrical signal;
performing an analog to digital conversion on the analog electrical signal;
despreading the analog to digital converted signal using a CDMA technique; and
decoding the despread analog to digital converted signal.
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Accused Products
Abstract
An ultrasonic transmission system in which, for the purpose of transmission, a signal is used which generates a broadband signal by means of code spreading and is capable of eliminating any echoes by means of correlation. The transmission system exhibits a transmitter and a receiver. In this configuration, digital information is spread to a great bandwidth in accordance with a CDMA technique, D/A converted and then transmitted by means of ultrasound via an air Preferred applications of the present invention are air interfaces having a length of a few meters. One field of application is, for example, the connection of cordless handsets or hands-free telephones to telephones.
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Citations
6 Claims
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1. A method for transmitting voice data between a head part and a base part of a hands-free telephone, which comprises:
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compressing information, being the voice data, to be transmitted using compression coding;
digitizing the compressed information;
spreading the digitized information over a wider frequency band using a CDMA technique;
performing a digital to analog conversion on the spread digitized information;
converting the digital to analog converted spread information into an ultrasound signal;
transmitting the ultrasound signal via an air interface;
at a receiver component, receiving the transmitted ultrasound signal and converting the received ultrasonic signal into an analog electrical signal;
performing an analog to digital conversion on the analog electrical signal;
despreading the analog to digital converted signal using a CDMA technique; and
decoding the despread analog to digital converted signal. - View Dependent Claims (2, 3, 4)
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5. A hands-free telephone comprising an ultrasonic transmission system including:
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a compression coder for compression coding analog information;
wherein the analog information is voice data;
a CDMA spreader for spreading digital information, which is obtained from said coded analog information, to a number of carrier frequencies using a CDMA technique;
a digital to analog converter for digital to analog converting the spread information;
an ultrasonic transducer for converting the digital to analog converted spread information into an ultrasound signal and for transmitting the ultrasound signal over an air interface; and
a receiver including;
an ultrasonic transducer for receiving the transmitted ultrasound signal and for converting the received ultrasonic signal into an electrical signal;
an analog to digital converter for analog to digital converting the electrical signal; and
a CDMA despreader for despreading the analog to digital converted signal using a CDMA technique. - View Dependent Claims (6)
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Specification