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US 6,320,842 B1Granted
Spread spectrum communication apparatus
AssigneeCanon Kabushiki Kaisha
InventorNorihiro Mochizuki
Life of this patent
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Abstract
In a communication apparatus of the transmitting side, n number of parallel signals are respectively spread-modulated by the n number of spreading codes and summation thereof is obtained. Also, m number of parallel signals are respectively spread-modulated by the m number of spreading codes and summation thereof is obtained. These two signals are modulated with quadrature carriers, synthesized and transmitted to the receiving side.
Claims11
A spread spectrum communication apparatus comprising:
- first, second and third differential modulators, arranged for differentially encoding first, second and third data sequences into first, second and third differentially encoded data sequences;
- a first spread modulator arranged for spreading the first differentially encoded data sequence in accordance with a first spread code;
- a second spread modulator arranged for spreading the second differentially encoded data sequence in accordance with a second spread code different from the first spread code;
- a third spread modulator arranged for spreading the third differentially encoded data sequence in accordance with a third spread code different from the first and second spread codes;
- and
- a transmitter, arranged for transmitting an output from said first and second spread modulator, and for transmitting an output from said third spread modulator on a first phase of a carrier different from a second phase of the carrier on which an output from said first spread modulator is transmitted.
3 more elements
A spread spectrum communication apparatus comprising:
- first and second differential modulators, arranged for differentially encoding first and second transmission data in units of first and second code divided channels and forming first and second n-phase shift keying modulated signals, wherein n is a natural number;
- third and fourth differential modulators, arranged for differentially encoding third and fourth transmission data in units of third and fourth code divided channels and forming first and second π/n-shifted n-phase shift keying modulated signals;
- first, second, third and fourth spread modulators, arranged for spreading the first and second n-phase shift keying modulated signals and the first and second π/n-shifted n-phase shift keying modulated signals using corresponding spread codes different from each other;
- and
- a transmitter, arranged for transmitting an output from said first, second, third and fourth spread modulators.
2 more elements
A spread spectrum communication apparatus comprising:
- a differential modulator for encoding first, second and third transmission data into first and second differentially encoded data;
- and
- a spread modulator for spreading the first differentially encoded data in accordance with a first spreading code and spreading the second differentially encoded data in accordance with a second spreading code,
- wherein said differential modulator encodes the first, second and third transmission data such that a difference between the first and second transmission data is encoded into the first differentially encoded data and a difference between the second and third transmission data is encoded into the second differentially encoded data.
1 more element
A method for a spread spectrum communication, comprising the steps of:
- encoding first, second and third transmission data into first and second differentially encoded data;
- and
- spreading the first differentially encoded data in accordance with a first spreading code and spreading the second differentially encoded data in accordance wiht a second spreading code,
- wherein the first, second and third transmission data are encoded in said encoding step such that a difference between the first and second transmission data is encoded into the first differentially encoded data and a difference between the second and third transmission data is encoded into the second differentially encoded data.
1 more element
Dependencies are inferred from the claim text.