Patent ID: 7031289

Claim:
A baseband signal multiplexing circuit for multiplexing a plurality of baseband signals spread with different spread codes into one baseband signal, comprising: a plurality of baseband filters for respectively limiting bands of the respective baseband signals input thereto; adding means for adding and code-multiplexing the plurality of baseband signals with the bands limited by said respective baseband filters to produce one baseband signal; level adjusting means for adjusting an amplitude value of the baseband signal produced by said adding means based on a control signal to output the signal; D/A converting means for converting the baseband signal which is a digital signal outputted from said level adjusting means into an analog signal; and gain setting means for calculating a gain set value with which the amplitude value of the baseband signal outputted from said level adjusting means is adjusted to an amplitude value matching a dynamic range of said D/A converting means based on the number of transmission codes which is the number of multiplexed baseband signals, and for notifying said level adjusting means of the gain set value with said control signal.