| 摘要 |
<p>PROBLEM TO BE SOLVED: To perform carrier detection without changing any threshold value in a data mode during the period of synchronous integration by detecting the presence/ absence of carrier by comparing a value, for which held maximum values are successively added for each symbol, with a prescribed threshold value. SOLUTION: Corresponding to a control signal outputted by a reception control part 7, a switching part connects a synchronous integration part 3 and a carrier detection part 4. Afterwards, self-correlation is found by performing inverse spread to a received spread spectrum signal at a correlator, and the absolute value of amplitude of the self-correlation is found by an amplitude detection part 2. In this case, each time inverse spread is performed, the correlative value outputted from the detection part 2 is compared with a correlative value stored in a holding means by the latch means of a maximum value detection part 5, and the larger correlative value is updated and stored in the holding means. This operation is repeated and when the inverse spread is completed, the correlative value is supplied to an adder part 6. The adder part 6 adds the supplied correlative value for each symbol and supplies the result through the switching part 8 to the carrier detection part 4. When the correlative value reaches the prescribed threshold value within the period of synchronous integration, the detection part 4 discriminates the presence of 'carrier'.</p> |
