| 摘要 |
PROBLEM TO BE SOLVED: To provide a coding communication system in spread spectrum communication that can enhance noise immunity in the case of transmission reception so as to extend the communication distance without adopting a method where the number of chips of spread codes in the spread spectrum processing is increased to increase the communication amount. SOLUTION: At a transmitter side, a data spread section 6 applies spread processing to transmission data by using two systems of spread codes each having a different code length, outputs two systems of spread data, and a QPSK modulation section 7 makes the 2 systems of spread data respectively corresponding to I and Q components and outputs orthogonal modulation signals. At a receiver side, a QPSK demodulation section 11 extracts the orthogonal modulation signal, applies orthogonal demodulation to the signal to provide an output of I and Q channel signals, an inverse spread arithmetic section 16 uses each of the 2 systems of the spread codes to apply inverse spread processing to the I and Q channel signals and outputs a correlation signal denoting the correlation of the I and Q channel signals with respect to the 2 systems of spread codes as a result, and a block decoder 65 decodes the transmission data on the basis of two sets of the correlation signals. |
