| 摘要 |
<P>PROBLEM TO BE SOLVED: To provide a radio communication unit whose quadrature demodulation method and transmission capacity can be changed readily, and to provide its quadrature amplitude demodulation circuit. <P>SOLUTION: In a control unit 37, an inverter (INV) 371, an exclusive OR gate (EX-OR) 372, and a selectors (SELs) 374, 375 are provided. I channel and Q channel data in each 8 lines from analog/digital converters 29, 30 are sent to the inverter (INV) 371 and the exclusive OR gate (EX-OR) 372, respectively. In addition, according to a reception bit rate, by averaging a reversal of an error signal and sending it to amplifiers 27, 28, an offset control of the analog/digital converters 29, 30 is implemented. Also, by averaging an exclusive OR of an Most Significant Bit and the error signal and sending it to an automatic gain control amplifier 21, an AGC control of the analog/digital converters 29, 30 is implemented. <P>COPYRIGHT: (C)2004,JPO |
