发明名称 Spread spectrum transmission circuit
摘要 A transmission circuit includes a baseband circuit, spreading section, multiplier, digital modulator, quadrature modulator, and antenna. The baseband circuit generates and outputs at least one transmission data constituted by first and second channel data. The spreading section spreads the transmission data with a spreading code that differs for each transmission channel. The multiplier respectively weights the amplitudes of the first and second channel data by using a combination of two gain factors determined by a transmission data rate. The digital modulator digitally modulates the first and second channel data whose amplitudes are weighted by the multiplier. The quadrature modulator quadrature-modulates the digitally modulated first and second channel data and outputs the data as a, transmission signal. The antenna emits the transmission signal output from the quadrature modulator as a radio wave. The multiplier weights the amplitudes of the first and second channel data by using gain factors that keep power of the transmission signal output from the quadrature modulator constant regardless of the transmission data rate without changing the ratio of a combination of gain factors determined by the transmission data rate. <IMAGE>
申请公布号 EP1217759(A3) 申请公布日期 2004.04.07
申请号 EP20010130226 申请日期 2001.12.19
申请人 NEC CORPORATION 发明人 KURIHARA, KAZUHIRO
分类号 H04L27/20;H04B1/04;H04B1/707;H04J13/00 主分类号 H04L27/20
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