CDMA mobile communication system and communication method

Abstract

A radio communication system having a base station and a plurality of radio terminals, wherein each radio terminal having a transmission request transmits a reservation packet at arbitrary timing through a reservation channel in accordance with a CDMA scheme, and the base station assigns a traffic channel and a time slot to be used to each radio terminal requesting a reservation through a reply packet outputted onto a reply channel. On the reservation channel, a short spreading code corresponding to a matched filter is applied.

1 . A communication method in a radio communication system, wherein a base station and a plurality of radio terminals communicate in radio channels, said method comprising the steps of: 
 transmitting a reservation using Code Division Multiple Access (CDMA) from one of said plurality of radio terminals requesting data transmission;    receiving a reply from the base station, corresponding to the reservation, in the one radio terminal; and    transmitting a data packet from the one radio terminal in response to the reply,    wherein a single data packet is transmitted in response to a single reply packet.    
   
   
       2 . The method according to  claim 1 , wherein a single reservation is transmitted for a single data packet.  
   
   
       3 . The method according to  claim 2 , wherein a single data packet has a constant length not longer than a time slot.  
   
   
       4 . The method according to  claim 3 , wherein a call setup process between the one radio terminal and the base station is performed in advance, and 
 wherein the one radio terminal transmits a plurality of reservations and data packets after the call setup process.