Time switching transmit diversity device of a mobile communication system, especially capable of transceiving data with a time switching transmit diversity function

PURPOSE: A time switching transmit diversity device of a mobile communication system is provided to use one quadrature code only for one of user data, so that only one signal channel receiver for demodulating user data can be configured regardless of the number of transmit antennas, thereby simplifying a receiver structure. CONSTITUTION: A signal converter(611) inputs a signal combined with coded user data and a long code. A serial/parallel converter(613) converts a serial signal outputted from signal converter(611) the into a parallel signal. A multiplier(615) mixes an even-numbered signal outputted from the serial/parallel converter(613) with a quadrature code, and outputs the mixed signal. A multiplier(617) mixes an odd-numbered signal outputted from the serial/parallel converter(613) with the quadrature code, and outputs the mixed signal. A controller(600) generates a switch control signal to distribute signals to be transmitted to plural antennas. LPFs(623,625) low pass-filter PN spread signals of an I channel and a Q channel outputted from a switch(621), and output the filtered signals. Multipliers(631,633) mix the signals outputted from the LPFs(623,625) with a carrier, and up-convert the frequencies. An adder(641) adds the signals outputted from the multipliers(631,633), and outputs the added signals to a transmit antenna(A).