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US RE45,037 E1Granted
Method for modulation and transmission apparatus
AssigneeOptis Wireless Technology, LLC
InventorsYutaka Murakami, Masayuki Orihashi, Akihiko Matsuoka, Morikazu Sagawa
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Abstract
An input digital signal is periodically and alternately subjected to first modulation and second modulation, being thereby converted into a pair of a baseband I signal and a baseband Q signal. The first modulation and the second modulation are different from each other. The pair of the baseband I signal and the baseband Q signal are outputted. The first modulation may be at least 8-signal-point modulation while the second modulation may be phase shift keying.
Claims34
A method for modulation, comprising the steps of:
- regularly subjecting an input digital signal to first modulation and second modulation to convert the input digital signal into a pair of a baseband I signal and a baseband Q signal, the first modulation and the second modulation being different from each other;
- and
- outputting the pair of the baseband I signal and the baseband Q signal;
- wherein the first modulation is at least 8-signal-point modulation, and the second modulation is phase shift keying;
- wherein the phase shift keying provides periodically-spaced symbols which represent corresponding portions of the input digital signal in terms of differences between phases of the periodically-spaced symbols;
- and
- wherein the at least 8-signal-point modulation assigns logic states of the input digital signal to respective signal points for a first symbol in response to a signal point used by a second symbol of the phase shift keying which precedes the first symbol.
4 more elements
A transmission apparatus comprising:
- first means for periodically and alternately subjecting an input digital signal to first modulation and second modulation to convert the input digital signal into a pair of a baseband I signal and a baseband Q signal, the first modulation and the second modulation being different from each other, the first modulation being at least 8-signal-point modulation, the second modulation being phase shift keying;
- second means for outputting the pair of the baseband I signal and the baseband Q signal;
- wherein the phase shift keying provides periodically-spaced symbols which represent corresponding portions of the input digital signal in terms of differences between phases of the periodically-spaced symbols;
- wherein the at least 8-signal-point modulation assigns logic states of the input digital signal to respective signal points for a first symbol in response to a signal point used by a second symbol of the shift keying which precedes the first symbol;
- and
- wherein said first symbol is demodulated by using said second symbol which is not a known prescribed pattern but a part of information transmitted by said transmission apparatus.
3 more elements
A method for modulation, comprising the steps of:
- regularly subjecting an input digital signal having different transmission timings to first modulation and second modulation, respectively, to convert the input digital signal having different transmission timings into a pair of a baseband I signal and a baseband Q signal, the first modulation and the second modulation being different from each other;
- and outputting the pair of the baseband I signal and the baseband Q signal;
- wherein the first modulation is at least 8-signal-point modulation, and the second modulation is phase shift keying;
- wherein the phase shift keying provides periodically-spaced symbols which represent corresponding portions of the input digital signal in terms of differences between phases of the periodically-spaced symbols;
- and wherein the at least 8-signal-point modulation assigns logic states of the input digital signal having different transmission timings to respective signal points for a first symbol in response to a signal point used by a second symbol of the phase shift keying which precedes the first symbol.
2 more elements
A transmission apparatus comprising:
- first means for periodically and alternately subjecting an input digital signal having different transmission timings to first modulation and second modulation, respectively, to convert the input digital signal having different transmission timings into a pair of a baseband I signal and a baseband Q signal, the first modulation and the second modulation being different from each other, the first modulation being at least 8-signal-point modulation, the second modulation being phase shift keying;
- second means for outputting the pair of the baseband I signal and the baseband Q signal;
- wherein the phase shift keying provides periodically-spaced symbols which represent corresponding portions of the input digital signal in terms of differences between phases of the periodically-spaced symbols;
- wherein the at least 8-signal-point modulation assigns logic states of the input digital signal having different transmission timings to respective signal points for a first symbol in response to a signal point used by a second symbol of the shift keying which precedes the first symbol;
- and wherein said first symbol is demodulated by using said second symbol which is not a known prescribed pattern but a part of information transmitted by said transmission apparatus.
2 more elements
Dependencies are inferred from the claim text.