CDMA radio transmission apparatus, CDMA radio reception apparatus, and CDMA radio communication method

Abstract

A CDMA radio transmission apparatus includes a spreader, a chip interleaver, and a transmitter. The spreader divides one symbol to a plurality of N chips equal to a number of a plurality of N slots contained in a frame, by spreading the one symbol by a spreading factor N equal to the number of the plurality of N slots contained in the frame. The chip interleaver performs a chip interleaving processing, whereby each of the plurality of N chips is equally assigned to each of the plurality of N slots. The transmitter operates to transmit the plurality of N slots in sequence.

We claim:  
     
         1 . A CDMA radio transmission apparatus, comprising: 
 a spreading system that divides one symbol to a plurality of N chips equal to a number of a plurality of N slots contained in one frame, by spreading said one symbol by a spreading factor N equal to the number of the plurality of N slots contained in the one frame;    a chip interleaving section that performs chip interleaving processing whereby each of the plurality of N chips is equally assigned to each of the plurality of N slots; and    a transmission section that transmits the plurality of N slots in sequence.    
     
     
         2 . The CDMA radio transmission apparatus according to  claim 1 , further comprising a control section that performs a low rate transmission power control to the plurality of N slots, the low rate transmission power control being adaptable to at least one of attenuation caused by distance variation and shadowing.  
     
     
         3 . The CDMA radio transmission apparatus according to  claim 1 , further comprising a decreaser that decreases the transmission power of the plurality of N slots when the quality of received data at a CDMA radio reception apparatus exceeds a threshold.  
     
     
         4 . The CDMA radio transmission apparatus according to  claim 1 , further comprising a control section that controls the transmission power of the plurality of N slots such that the transmission power is increased as a quality of the received data at a CDMA radio reception apparatus increases, and is decreased as the quality of the received data at the CDMA radio reception apparatus decreases.  
     
     
         5 . A CDMA radio transmission apparatus according to  claim 1 , further comprising: 
 an amplitude controller that controls an amplitude to gradually increase a transmission power of the plurality of N slots; and    a transmission controller that discontinues slot transmission when a reception level of a slot received in a CDMA radio reception apparatus exceeds a threshold.    
     
     
         6 . A CDMA radio reception apparatus, comprising: 
 a reception section that receives in sequence a plurality of N slots, to each of which each of a plurality of N chips equal to a number of the plurality of N slots is equally assigned, the plurality of N chips obtained by spreading one symbol by a spreading factor N equal to the number of the plurality of N slots contained in one frame in a CDMA radio transmission apparatus; and    a chip deinterleaving section that performs chip deinterleaving processing on the plurality of N chips.    
     
     
         7 . The CDMA radio reception apparatus according to  claim 6 , further comprising a likelihood estimator that performs likelihood estimation on data subjected to chip deinterleaving processing.  
     
     
         8 . The CDMA radio reception apparatus according to  claim 6 , further comprising: 
 a level detector that detects a reception level of data subjected to the chip deinterleaving processing; and    a judgment section that performs a threshold judgment on the detected reception level and instructs the CDMA radio transmission apparatus to discontinue slot transmission when the detected reception level exceeds a threshold.    
     
     
         9 . The CDMA radio reception apparatus according to  claim 6 , further comprising: 
 a level detector that detects a reception level of data subjected to the chip deinterleaving processing;    an adder that adds the detected reception level; and    a judgment section that performs a threshold judgment on the added reception level and instructs the CDMA radio transmission apparatus to discontinue slot transmission when the added reception level exceeds a threshold.    
     
     
         10 . A CDMA radio communication method, comprising: 
 dividing one symbol to a plurality of N chips equal to a number of a plurality of N slots contained in one frame, by spreading said one symbol by a spreading factor N equal to the number of the plurality of N slots contained in the one frame;    performing chip interleaving processing whereby each of the plurality of N chips is equally assigned to each of the plurality of N slots; and    transmitting the plurality of N slots in sequence.    
     
     
         11 . A CDMA radio communication method, comprising: 
 receiving in sequence a plurality of N slots, to each of which each of a plurality of N chips equal to a number of the plurality of N slots is equally assigned, the plurality of N chips obtained by spreading one symbol by a spreading factor N equal to the number of the plurality of N slots contained in one frame in a CDMA radio transmission apparatus; and    performing chip deinterleaving processing on the plurality of N chips.