Mobile radio communication system which allocates spread codes mobiles which are able to determine the distance between a mobile and a base station

摘要

In a mobile radio communication system for performing radio communication between a base station and a plurality of mobile stations by a code division multiple access method, a plurality of slots (T1 to T4) for a forward link from a base station (BS) to a mobile station (MS) and a plurality of slots R1 to R4 for a reverse link from the mobile station (MS) to the base station (BS) are set on a first radio frequency f2 in a time-division multiplexing manner. The slots are set in accordance with the distance between the base station and the mobile station, and the transmission power of the base station in each slot is associated with this distance. The transmission power is low in the slot associated with a short distance between the base station and the mobile station, and the transmission power is high in the slot associated a long distance between the base station and the mobile station. The mobile station (MS) detects the received electric field intensity of a pilot/sync signal coming from the base station (BS) with a second radio frequency, and sends the detected information to the base station (BS). On the basis of the detected value of the received electric field intensity of the mobile station (MS) sent from the mobile station (MS), the base station (BS) determines the distance between the base station and the mobile station, selects the associated pair of slots from among the pairs of slots T1/R1 to T4/R4, thereby allocating the selected slots to this mobile station (MS).