| 摘要 |
PURPOSE: To recognize the switching between a preamble and an information signal at a low-order level by comparing the preamble which is correlatively demodulated by a diffusion code with the reference value and recognizing a changing point to the transmission of information from the preamble. CONSTITUTION: The code generator 105 of a receiver outputs a pilot code 301 that is outputted by a transmitter as a preamble in addition to a diffusion code 205 that is used for correlative demodulation of every information channel. The code 301 is demodulated by a correlator 302. The preamble of the demodulated pilot signal is compared with the reference value by a comparator 304. When the preamble is smaller than the reference value, a changing point to the transmission of information from the preamble is recognized and the corresponding treatment is carried out at a data processing part 10. The timing when the preamble shifts to the transmission of an information signal can be decided at a low-order level without putting a unique word into a data stream. In such a constitution signal can be decided at a low-order level is reduced and deterioration of the transmission efficiency can be prevented. |
