发明授权
- 专利标题: .pi./4 shift QPSK modulator and communication apparatus
- 专利标题(中): pi / 4移位QPSK调制器和通信设备
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申请号: US653895申请日: 1991-02-12
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公开(公告)号: US5210775A公开(公告)日: 1993-05-11
- 发明人: Yasuaki Takahara , Tomohiro Ezaki , Shigeyuki Sudo , Teiji Okamoto
- 申请人: Yasuaki Takahara , Tomohiro Ezaki , Shigeyuki Sudo , Teiji Okamoto
- 申请人地址: JPX Tokyo
- 专利权人: Hitachi, Ltd.
- 当前专利权人: Hitachi, Ltd.
- 当前专利权人地址: JPX Tokyo
- 优先权: JPX2-29579 19900213
- 主分类号: H04L27/20
- IPC分类号: H04L27/20
摘要:
A .pi./4 shift QPSK modulator for receiving digital signals and for outputting a modulated signal therefrom in accordance with each of the inputted digital signals. The .pi./4 QPSK modulator is utilized in a communication apparatus and includes a counter for counting the number of the inputted digital signals, a phase information arithmetic unit for receiving a value of an output from the counter and a value of each of the inputted digital signals for outputting phase information of the signal to be modulated, an arithmetic unit for performing an arithmetic operation on values representing an impulse response of the output phase information from the phase information arithmetic unit and outputting impulse response values in accordance therewith, and an accumulating unit for accumulating impulse response values outputted from the arithmetic unit and for performing an arithmetic operation for enabling generation of a .pi./4 shift QPSK modulated signal.
公开/授权文献
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