Spread spectrum conference call system and method
First Claim
1. A spread-spectrum conference calling communications system for simultaneously listening to a plurality of spread-spectrum channels of a spread-spectrum-communications signal comprising:
- generic-spread-spectrum-processing means for recovering a carrier signal from the spread-spectrum-communications signal and for generating a replica of a generic-chip-code signal; and
a plurality of spread-spectrum receivers, each of said spread-spectrum receivers including,acquisition means responsive to acquiring and tracking the recovered carrier signal for synchronizing said generic-spread-spectrum-processing means to the recovered carrier signal;
message-spread-spectrum-processing means for despreading the spread-spectrum-communications signal as a plurality of modulated-data signals; and
demodulation means for demodulating the modulated-data signal as a demodulated signal, said demodulation means including detection means for sequentially detecting each of the plurality of modulated-data signals as a detected signal, respectively.
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Accused Products
Abstract
A spread spectrum communications system for use over a communications channel, including a transmitter-generic-chip-code generator, a transmitter-message-chip-code generator, an EXCLUSIVE-OR gate, a combiner, a transmitter, a receiver-generic-chip-code generator, a generic mixer, a generic-bandpass filter, a receiver-message-chip-code generator, a message mixer, a message-bandpass filter, and a synchronous detector. The transmitter-generic-chip-code generator generates a generic-chip-code signal and the transmitter-message-chip-code generator generates a message-chip-code signal. The EXCLUSIVE-OR gate spread-spectrum processes message data with the message-chip-code signal to generate a spread-spectrum signal. The combiner combines the generic-chip-code signal with the spread-spectrum signal. The transmitter transmits the combined generic-chip-code signal and spread-spectrum signal, on a carrier signal over the communications channel as a spread-spectrum-communications signal. The receiver-generic-chip-code generator generates a replica of the generic-chip-code signal. The generic mixer recovers the carrier signal from the spread-spectrum-communications signal. The receiver-message-chip-code generator generates a replica of the message-chip-code signal. The message mixer despreads the spread-spectrum-communications signal as a modulated-data signal. The tracking and acquisition circuit uses the recovered carrier signal for synchronizing the replicas of the generic-chip-code signal to the recovered carrier signal. The synchronous detector synchronously demodulates the modulated-data signal as received data.
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Citations
17 Claims
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1. A spread-spectrum conference calling communications system for simultaneously listening to a plurality of spread-spectrum channels of a spread-spectrum-communications signal comprising:
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generic-spread-spectrum-processing means for recovering a carrier signal from the spread-spectrum-communications signal and for generating a replica of a generic-chip-code signal; and a plurality of spread-spectrum receivers, each of said spread-spectrum receivers including, acquisition means responsive to acquiring and tracking the recovered carrier signal for synchronizing said generic-spread-spectrum-processing means to the recovered carrier signal; message-spread-spectrum-processing means for despreading the spread-spectrum-communications signal as a plurality of modulated-data signals; and demodulation means for demodulating the modulated-data signal as a demodulated signal, said demodulation means including detection means for sequentially detecting each of the plurality of modulated-data signals as a detected signal, respectively. - View Dependent Claims (2, 3, 4, 5)
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6. A method for receiving spread-spectrum conference calls, comprising the steps of:
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recovering, using a replica of a generic-chip-code signal, a carrier signal from a spread-spectrum-communications signal; acquiring and tracking the recovered-carrier signal; generating the replica of the generic-chip-code signal synchronized to the recovered-carrier signal; generating a replica of the message-chip-code signal;
synchronized to the replica of the generic-chip-code signal;despreading, using the replica of the message-chip-code signal, the spread-spectrum-communications signal as a modulated-data signal; synchronizing the replica of the generic-chip-code signal to the recovered carrier signal; and demodulating the modulated-data signal as received data. - View Dependent Claims (7)
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8. A spread-spectrum conference calling communications system for simultaneously listening to a plurality of spread-spectrum channels of a spread-spectrum-communications signal comprising:
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generic-spread-spectrum-processing means for recovering a carrier signal from the spread-spectrum-communications signal and for generating a replica of a generic-chip-code signal; and a plurality of spread-spectrum receivers, each of said spread-spectrum receivers including, acquisition means responsive to acquiring and tracking the recovered carrier signal for synchronizing said generic-spread-spectrum-processing means to the recovered carrier signal; message-spread-spectrum-processing means for despreading the spread-spectrum-communications signal as a plurality of modulated-data signals; and demodulation means for demodulating the modulated-data signal as a demodulated signal. - View Dependent Claims (9, 10, 11, 12)
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13. A spread-spectrum conference calling communications system for simultaneously listening to a plurality of spread-spectrum channels of a spread-spectrum-communications signal comprising:
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a receiver-generic-chip-code generator for recovering a carrier signal from the spread-spectrum-communications signal and for generating a replica of a generic-chip-code signal; and a plurality of spread-spectrum receivers, each of said spread-spectrum receivers including, an acquisition and tracking circuit, responsive to acquiring and tracking the recovered carrier signal, for synchronizing said receiver-generic-chip-code generator to the recovered carrier signal; a receiver-message-chip-code generator for despreading the spread-spectrum-communications signal as a plurality of modulated-data signals; and demodulation means for demodulating the modulated-data signal as a demodulated signal. - View Dependent Claims (14, 15, 16, 17)
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Specification