| 摘要 |
PURPOSE:To demodulate a data With a single correlation device by applying spread modulation to a reference signal and plural information signals With a retarded PN code respectively, multiplexing them, transmitting the result and using the single correlation device to apply correlation calculation to the multiplexed reception signal and the reference signal. CONSTITUTION:A sender side synthesizes a reference signal and an information signal (data) and sends the result, a sender side applies serial/parallel conversion to an inputted high speed data at a circuit 101 and applies spread modulation for each channel. Then the modulated signal is retarded sequentially by a shift register 107 at each channel based on a sounder and modulates a high frequency carrier signal by each delay signal and the result is synthesized and sent. A receiver side takes correlation to a reception signal with a single correlation device. A PN code used for the reference signal of the correlation device is selected so as to cause correlation spike when, e.g. a data is logical 1. Even in the case of the multiplexed spread spectral communication, one correlation device is enough for the processing and the circuit is simplified. |
