发明授权
- 专利标题: QPSK/QBL-MSK waveform enhancement
- 专利标题(中): QPSK / QBL-MSK波形增强
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申请号: US708807申请日: 1996-09-09
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公开(公告)号: US5818867A公开(公告)日: 1998-10-06
- 发明人: Donald J. Rasmussen , Timothy P. Dempsey , Daniel D. Shearer, III
- 申请人: Donald J. Rasmussen , Timothy P. Dempsey , Daniel D. Shearer, III
- 申请人地址: NY White Plains
- 专利权人: ITT Industries, Inc.
- 当前专利权人: ITT Industries, Inc.
- 当前专利权人地址: NY White Plains
- 主分类号: H04B1/707
- IPC分类号: H04B1/707 ; H04L27/20 ; H04B15/00 ; H04K1/00 ; H04L27/30
摘要:
A modulator device is disclosed for a spread spectrum communication system which generates a modulated signal from incoming data. The device includes a QPSK portion for separating the incoming data into two data channels and for further spreading the two channels over a wide bandwidth according to a predetermined spreading code. A phase mapping element coupled to the QPSK portion for processing both channels in order to minimize spectral regrowth of the modulated signal by preventing the RF envelope deviation from going close to zero. Pulse shaping elements coupled to the phase mapping element for further processing each channel in order to improve the modulator spectral efficiency and minimize adjacent channel interference. A quad-mixer coupled to the pulse shaping elements for combining both channels into a recombined signal and for further modulating the recombined signal according to a predetermined carrier frequency.
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