| 摘要 |
PURPOSE: To increase the number of users without increasing a spread band or reducing data transmission speed by performing spread spectrum modulation to transmission data signals, performing sampling, then extracting the signals of a prescribed band width and generating transmission signals. CONSTITUTION: On a transmission side, input data signals are sampled (21), replicas are generated on a frequency axis and transmission to a spread modulator 23 is performed after modulation (23). In the modulator 23, spread code signals are multiplied with data modulation signals, spread modulation is performed and the band is widened in a base band. Then, the real number component and imaginary number component of digital signals are respectively turned to analog (27 and 28), a prescribed band is extracted in BPFs 29 and 30, frequency conversion (31 and 32) is performed, addition (35) is performed and the transmission from an antenna 36 is performed. On a reception side, after extracting the signals of the prescribed band, spread spectrum demodulation is performed. |
