Simultaneous voice and data modem
First Claim
Patent Images
1. A modem for simultaneous communication of voice and data comprising:
- a voice input circuit for receiving digital samples of voice content;
a data input circuit for receiving digital data for transmission;
a modulator for modulating a predetermined audio frequency carrier with the received digital data to form a modulated data signal; and
a digital signal processing module for combining the voice content and the modulated data signal together for simultaneous transmission over a single voice communication channel by reducing the frequency spectrum of the voice content to frequencies below approximately a first frequency cutoff value selected so as to substantially preserve the voice content, and wherein the modulated data signal is limited in frequency spectrum to frequencies above approximately the first frequency cutoff value so as to minimize interference with the voice content.
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Abstract
Simultaneous transmission of voice and data over the voice channel of a wireless communications network, such as a “cell phone” network, is reconfigurable on the fly among multiple operating modes, including a lull detection mode in which data is transferred during a lull or quiet period in the voice content. Additionally, control signaling in the voice channel, rather than over a separate control or “overhead” channel is employed to support SVD. The described system operates transparently over any wireless telecommunications system.
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Citations
39 Claims
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1. A modem for simultaneous communication of voice and data comprising:
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a voice input circuit for receiving digital samples of voice content;
a data input circuit for receiving digital data for transmission;
a modulator for modulating a predetermined audio frequency carrier with the received digital data to form a modulated data signal; and
a digital signal processing module for combining the voice content and the modulated data signal together for simultaneous transmission over a single voice communication channel by reducing the frequency spectrum of the voice content to frequencies below approximately a first frequency cutoff value selected so as to substantially preserve the voice content, and wherein the modulated data signal is limited in frequency spectrum to frequencies above approximately the first frequency cutoff value so as to minimize interference with the voice content. - View Dependent Claims (2, 3, 4, 5, 6)
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7. An asymmetric method of operation of a wireless communication system for voice and data communication over a single voice channel, the method comprising the steps of:
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transmitting voice and data from a wireless mobile unit to a base station using a continuous voice and data mode of operation; and
transmitting voice and data from the base station to the wireless mobile unit using a data burst with reduced voice spectrum mode of operation. - View Dependent Claims (8, 9)
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10. A method of simultaneous transmission of voice content and data over a single voice channel of a wireless telecommunications system, the voice channel being established between first and second stations, and the method comprising the steps of:
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transmitting voice content from the first station to the second station over the voice channel;
while transmitting voice content, monitoring the voice content to detect a lull;
responsive to detecting a lull in the voice content, reducing the frequency spectrum of the transmitted voice content and continuing to transmit voice content; and
also responsive to said detecting a lull in the voice content, commencing simultaneous transmission of data over the voice channel. - View Dependent Claims (11, 12, 13, 14, 15, 16, 17, 18, 19, 20, 21, 22)
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23. A method of simultaneous transmission of voice content and data over a single voice channel of a wireless telecommunications system, the voice channel being established between first and second stations, and the method comprising the steps of:
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partitioning the voice channel so as to comprise three bands, namely a voice band, a data band and a control band, all within the audio range of frequencies;
transmitting voice content from the first station to the second station over the voice band of the voice channel;
while transmitting voice content, monitoring the voice content to detect a lull; and
responsive to detecting a lull in the voice content, transmitting data over the data band of the voice channel while continuing to simultaneously transmit voice content over the voice band of the voice channel. - View Dependent Claims (24, 25, 26, 27, 28, 29, 30, 31, 32)
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33. A method of simultaneous transmission of voice content and data over a single voice channel of a wireless telecommunications system, the voice channel being established between first and second stations, and the method comprising the steps of:
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band limiting the voice content to frequencies up to approximately a first predetermined audio frequency while data is not being transmitted;
while transmitting voice content, monitoring the voice content to detect a lull;
responsive to detecting a lull in the voice content, further band limiting the voice content to frequencies up to approximately a second predetermined audio frequency, the second frequency being lower than the first frequency, thereby reducing the voice spectrum of the transmitted signal while data also is being transmitted; and
also responsive to said detecting a lull in the voice content, commencing simultaneous transmission of data over the voice channel. - View Dependent Claims (34, 35, 36, 37, 38, 39)
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Specification