Patent ID: 6532249
Filing Date: 2003-03-11
Classification: H04B

Abstract:
A transmitter for use in a multiple frequency radio communication system providing a plurality of frequency bandwidths, the transmitter comprising:a clock generating section for receiving a predetermined bandwidth selecting control signal and then generating a clock having a speed in proportion to the predetermined bandwidth; a multiplexing section for inserting zero into a signal, spread modulated in a bandwidth selected according to the predetermined bandwidth selecting control signal, to produce an oversampled signal; a lowpass filter for receiving the clock and for lowpass filtering an output signal of the multiplexing section; a digital/analog converter for receiving the clock and then converting an output signal of the lowpass filter into an analog signal at said clock speed; and a switch for receiving the bandwidth selecting control signal and then switching an output of the digital/analog converter to a corresponding one of a plurality of intermediate frequency circuits according to the selected bandwidth.