CDMA communication system and its transmission power control method

Abstract

An uplink channel transmission power control method is provided for a CDMA mobile communication system performing one way communication. A base station measures the received level of data transmitted from each mobile terminal at each channel, and generates a transmission power control signal of each uplink traffic channel. The generated transmission power control signals are multiplexed, and the multiplexed common transmission power control signal is transmitted to all mobile terminals by using the common channel shared by the mobile terminals. Each mobile terminal derives the transmission power control signal of the uplink traffic channel used by the terminal, from the received common transmission power control signal, and controls the transmission power of a data packet.

1 - 26 . (canceled)  
     
     
         27 . A base station for communicating with a plurality of terminals in a CDMA method, comprising: 
 a control signal generator that generates transmission power control signals  1 -n corresponding to uplink traffic channels  1 -n for uplink data transmission with the plurality of terminals; and    a spreader that spreads the transmission power control signals constituted in an order of  1 -n,    wherein the transmission power control signals thus spread are transmitted to the terminals via a channel in common to the plurality of terminals.    
     
     
         28 . The base station according to  claim 27 , further comprising an adder that multiplexes the spread transmission power control signals with downlink traffic channels  1 -n for downlink data transmission.  
     
     
         29 . The base station according to  claim 27 , further comprising a receiver that receives a signal from a terminal, 
 wherein the control signal generator generates the transmission power control signal corresponding to the signal thus received.    
     
     
         30 . A terminal for communicating with a base station in a CDMA method, comprising a despread circuit that despreads spread transmission power control signals by using a spread code in common to a plurality of terminals, with the spread transmission power control signals being transmitted from the base station via a channel in common to the plurality of terminals, and being configured in an order of  1 -n corresponding to uplink traffic channels  1 -n for uplink data transmission.  
     
     
         31 . The terminal according to  claim 30 , further comprising a transmitter that transmits a signal in accordance with transmission power determined based on the transmission power control signal thus received.  
     
     
         32 . The terminal according to  claim 30 , further comprising a transmission power correction unit that selects a transmission power control signal corresponding to the own terminal, from the transmission power control signals transmitted via the channel in common to the plurality of terminals.