Method and apparatus for transmitting control information in wireless communication system

Abstract

The present invention relates to a wireless communication system. More specifically, the present invention relates to a method for transmitting control information through a PUCCH in a wireless communication system and an apparatus for same comprising the steps of: obtaining a plurality of second modulation symbol streams corresponding to a plurality of SC-FDMA (Single Carrier Frequency Division Multiplexing) symbols by diffusing a plurality of first modulation symbol streams to form the first modulation symbol streams corresponding to the SC-FDMA symbols within a first slot; obtaining a plurality of complex symbol streams by performing a DFT (Discrete Fourier Transform) pre-coding process for the plurality of second modulation symbol streams; and transmitting the plurality of complex symbol streams through the PUCCH wherein the plurality of second modulation symbol streams are scrambled in a SC-FDMA symbol level.

The invention claimed is: 
     
       1. A method for, at a user equipment (UE), transmitting control information an uplink signal through a physical uplink control channel (PUCCH) in a wireless communication system, the method comprising:
 generating a first modulation symbol sequence from control information;  
 spreading a first modulated symbol sequence such that the first modulated symbol sequence corresponds to a plurality of single carrier-frequency division multiplexing (SC-FDMA) symbols in a first slot, to obtain a plurality of second modulated symbol sequences corresponding to the plurality of SC-FDMA symbols; and  
 performing a discrete Fourier transform (DFT) precoding on the plurality of second modulated symbol sequences to obtain a plurality of complex symbol sequences; and 
 transmitting the a plurality of complex symbol sequences through a plurality of single carrier-frequency division multiplexing (SC-FDMA) symbols of a first slot of the PUCCH, 
 wherein each sequence of the plurality of the complex symbol sequences carries discrete Fourier transformed (DFTed) symbols related to a respective sequence of the plurality of second modulation symbol sequences,  
 wherein scrambling is applied to the plurality of second modulated symbol sequences at SC-FDMA symbol level using a multiplication of c i  by a respective modulated symbol sequence of the plurality of second modulated symbol sequences, and 
 wherein c i  is a scrambling value for a corresponding SC-FDMA symbol. 
 
     
     
       2. The method of  claim 1 ,
 wherein a value for the scrambling value is obtained using the following equation: 
 
       
         
           
             
               
                 
                   
                     n 
                     cs 
                     cell 
                   
                   ⁡ 
                   
                     ( 
                     
                       
                         n 
                         s 
                       
                       , 
                       l 
                     
                     ) 
                   
                 
                 = 
                 
                   
                     ∑ 
                     
                       i 
                       = 
                       0 
                     
                     7 
                   
                   ⁢ 
                   
                     
                       c 
                       ⁡ 
                       
                         ( 
                         
                           
                             8 
                             ⁢ 
                             
                                 
                             
                             ⁢ 
                             
                               
                                 N 
                                 symb 
                                 UL 
                               
                               · 
                               
                                 n 
                                 s 
                               
                             
                           
                           + 
                           
                             8 
                             ⁢ 
                             
                                 
                             
                             ⁢ 
                             l 
                           
                           + 
                           i 
                         
                         ) 
                       
                     
                     · 
                     
                       2 
                       i 
                     
                   
                 
               
               , 
             
           
         
         wherein n cs   cell (n s ,l) is a cell-specific cyclic shift value, c( ) is a pseudo-random sequence generation function, N symbol   UL  is the a number of SC-FDMA symbols in a slot, n s  is a slot index of the first slot, and l denotes an SC-FDMA symbol index. 
       
     
     
       3. The method of  claim 2 , wherein the pseudo-random sequence generation function is initialized using a cell ID. 
     
     
       4. A user equipment (UE) configured to transmit control information through a physical uplink control channel (PUCCH) in a wireless communication system, the UE comprising:
 a radio frequency (RF) unit; and   a processor,   wherein the processor is configured to spread a first modulated symbol sequence such that the first modulated symbol sequence corresponds to a plurality of single carrier-frequency division multiplexing (SC-FDMA) symbols in a first slot, to obtain a plurality of second modulated symbol sequences corresponding to the plurality of SC-FDMA symbols, to perform a discrete Fourier transform (DFT) precoding on the plurality of second modulated symbol sequences to obtain a plurality of complex symbol sequences, and to transmit the plurality of complex symbol sequences through the PUCCH,   wherein scrambling is applied to the plurality of second modulated symbol sequences at SC-FDMA symbol level using multiplication of c i  by a respective modulated symbol sequence of the plurality of second modulated symbol sequences, and   wherein c i  is a scrambling value for a corresponding SC-FDMA symbol.   
     
     
       5. The UE of  claim 4 , wherein a value for the scrambling is obtained using the following equation:
   n cs   cell (n s ,l)=Σ i=0   7 c(8N symb   UL ·n s +8l+i)·2 i ,
   wherein n cs   cell (n s ,l) is a cell-specific cyclic shift value, c( ) is a pseudo-random sequence generation function, N symb   UL  is the number of SC-FDMA symbols in a slot, n s  is a slot index, and l is an SC-FDMA symbol index.   
     
     
       6. The UE of  claim 5 , wherein the pseudo-random sequence generation function is initialized using a cell ID.