| 摘要 |
PROBLEM TO BE SOLVED: To avoid requirement of high accuracy in power control of an inverse direction link by improving performance of a code division multiple address CDMA inverse direction link. SOLUTION: A timing of a signal received from each transmission subscriber station 3 is matched accurately and when symbol borders sent from all the transmission subscriber stations 3 are received by a base station 1, they are entered in a tip interval. At first each subscriber unit synchronizes a tip rate with a code phase. Radio transmission delay to the base station station 1 from each subscriber is equalized in the tip interval. The radio transmission delay made by the base station 1 is measured (15, 18) as follows; At first, a pseudo noise series sent by the subscriber is used in response to the request in an idle interval to warrant correct operation of a random access trial by the subscriber unit. On the other hand, CDMA transmission of the subscriber unit is used during talking to conduct closed loop control for delay equalization during speech to compensate slight fluctuation in the delay time. |
