Patent ID: 7023897
Filing Date: 2006-04-04
Classification: H04B,H04J

Abstract:
1. A transmission circuit, comprising: a baseband circuit for generating and outputting transmission data including first and second channel data; a spreading unit for spreading the transmission data with a spreading code that differs for each transmission channel; a multiplication unit for respectively weighting amplitudes of the first and second channel data by using a combination of two gain factors determined by a transmission data rate; a digital modulation unit for digitally modulating the first and second channel data whose amplitudes are weighted by said multiplication unit; and a quadrature modulator for quadrature-modulating the first and second channel data digitally modulated by said digital modulation unit and outputting the data as a transmission signal, wherein: said multiplication unit weights the amplitudes of the first and second channel data by using gain factors that keep power of the transmission signal output from said quadrature modulator constant regardless of the transmission data rate without changing a ratio of a combination of gain factors determined by the transmission data rate, and said multiplication unit weights the amplitudes of the first and second channel data by using gain factors determined on the basis of the power of the transmission signal output from said quadrature modulator without changing the ratio of the combination of gain factors determined by the transmission data rate.