| 摘要 |
<P>PROBLEM TO BE SOLVED: To provide a radio apparatus for efficiently reducing circumferential noise with an inexpensive configuration. <P>SOLUTION: A radio apparatus 1 includes: a sound microphone 11-1 for collecting sound and circumferential noise; a circumferential noise microphone 11-2 for collecting circumferential noise; a stereo codec 12 having a Lch to which the sound microphone 11-1 is connected, a Rch to which the circumferential noise microphone 11-2 is connected, a programmable gain amplifier (PGA) 121 for amplifying an input to the Lch, an analog/digital converter (ADC) 123 for digitally converting the output of the PGA 121, a PGA 122 for amplifying an input to the Rch, and an ADC 124 for digitally converting the output of the PGA 122; a digital signal processor (DSP) 13 for canceling the same phase noise components and outputting only a sound signal with software processing concerning a first digital signal from the ADC 123 and a second digital signal from the ADC 124; an orthogonal modulator 15 which is a transmission part for converting an output signal from the DSP 13 into a radio signal and transmitting it; a power amplifier 16; and an antenna 17. <P>COPYRIGHT: (C)2013,JPO&INPIT |
