| 摘要 |
PROBLEM TO BE SOLVED: To demodulate a direct sequence-spectrum spreading (DS-SS) signal, which is subjected to differential code phase shift keying(DQOSK) demodulation. SOLUTION: An A to D converter 2 is made to discretely fetch a signal in a 1/4 cycle of a carrier frequency and to transmit it to a delay line 3. The delay line 3 obtains an intermediate correlation output of the same phase quadrature component from output terminals IOUT 1 and QOUT 1. Also, regarding a signal one symbol befor, the intermediate correlation output of the same phase, the quadrature component is obtained from the output terminals IOUT 2 and QOUT 2 of a delay line 4. Then, the addition signal of the output terminals IOUT 2 and QOUT 2 and a signal of the output terminal IOUT 1 and a multiplication signal are made to be an output signal IOUT of the same component, and the addition signal of the output terminals IOUT 2 and QOUT 2, and the signal of the output terminal QOUT 1 and the multiplication signal are made to be the output signal QOUT of the quadrature component. |
