Downlink 8 Tx codebook sub-sampling for CSI feedback

Abstract

This invention is codebook sub-sampling of the reporting of RI, CQI, W 1 and W 2 . If CSI mode 1 is selected RI and W 1 are jointly encoded using codebook sub-sampling in report 1. If CSI mode 2 is selected W 1 and W 2 are jointly encoded using codebook sub-sampling in report 2.

What is claimed is:  
     
       1. A transceiver, comprising:
 a receiver for receiving; and 
 a transmitter for transmitting via a Physical Uplink Control CHannel (PUCCH) a Channel State Information feedback signal having:
 a first mode with a first report jointly coding Rank Indicator (RI) and a first Precoding Matrix Indicator (PMI), and with a second report coding Channel Quality Indicator (CQI) and a second PMI, wherein said jointly coding the RI and the first PMI employs codebook sub-sampling into a maximum of 5 bits as follows: 
 
 
       
         
           
                 
                 
                 
               
                     
                 
                     
                   RI 
                   Codebook index (i 1 ) 
                 
                     
                 
                     
                   1 
                   0, 2, 4, 6, 8, 10, 12, 14 
                 
                     
                   2 
                   0, 2, 4, 6, 8, 10, 12, 14 
                 
                     
                   3 
                   0, 2 
                 
                     
                   4 
                   0, 2 
                 
                     
                 
             
                
                
                
               
               
                
                
                
                
                
               
            
           
         
         and
 a second mode with a first report coding RI, and with a second report coding CQI and jointly coding the first PMI and the second PMI, wherein said jointly coding the first PMI and the second PMI employs codebook sub-sampling. 
 
       
     
     
       2. A transceiver, comprising:
 a receiver for receiving; and 
 a transmitter for transmitting via a Physical Uplink Control CHannel (PUCCH) a Channel State Information feedback signal having:
 a first mode with a first report jointly coding Rank Indicator (RI) and a first Precoding Matrix Indicator (PMI), and with a second report coding Channel Quality Indicator (CQI) and a second PMI, wherein for a 2-layer capable user equipment said jointly coding RI and the first PMI employs codebook sub-sampling into 4 bits as follows: 
 
 
       
         
           
                 
                 
                 
               
                     
                 
                     
                   RI 
                   Codebook index (i 1 ) 
                 
                     
                 
                     
                   1 
                   0, 2, 4, 6, 8, 10, 12, 14 
                 
                     
                   2 
                   0, 2, 4, 6, 8, 10, 12, 14 
                 
                     
                 
             
                
                
                
               
               
                
                
                
               
            
           
         
         and
 a second mode with a first report coding RI, and with a second report coding CQI and jointly coding the first PMI and the second PMI, wherein said jointly coding the first PMI and the second PMI employs codebook sub-sampling. 
 
       
     
     
       3. A transceiver, comprising:
 a receiver for receiving; and 
 a transmitter for transmitting via a Physical Uplink Control CHannel (PUCCH) a Channel State Information feedback signal having:
 a first mode with a first report jointly coding Rank Indicator (RI) and a first Precoding Matrix Indicator (PMI), and with a second report coding Channel Quality Indicator (CQI) and a second PMI, wherein said jointly coding the RI and the first PMI employs codebook sub-sampling; and 
 a second mode with a first report coding RI, and with a second report coding CQI and jointly coding the first PMI and the second PMI, wherein said jointly coding the first PMI and the second PMI employs codebook sub-sampling as follows for the first PMI: 
 
 
       
         
           
                 
                 
                 
               
                     
                 
                     
                   RI 
                   Codebook index (i 1 ) 
                 
                     
                 
                     
                   1 
                   0, 2, 4, 6, 8, 10, 12, 14 
                 
                     
                   2 
                   0, 2, 4, 6, 8, 10, 12, 14 
                 
                     
                   3 
                   0, 2 
                 
                     
                   4 
                   0, 2. 
                 
                     
                 
             
                
                
                
               
               
                
                
                
                
                
               
            
           
         
       
     
     
       4. A transceiver, comprising:
 a receiver for receiving; and 
 a transmitter for transmitting via a Physical Uplink Control CHannel (PUCCH) a Channel State Information feedback signal having:
 a first mode with a first report jointly coding Rank Indicator (RI) and a first Precoding Matrix Indicator (PMI), and with a second report coding Channel Quality Indicator (CQI) and a second PMI, wherein said jointly coding the RI and the first PMI employs codebook sub-sampling; and 
 a second mode with a first report coding RI, and with a second report coding CQI and jointly coding the first PMI and the second PMI, wherein said jointly coding the first PMI and the second PMI employs codebook sub-sampling: 
 for RI equal one joint coding the first PMI and the second PMI employs 7 bits or less, and 
 for RI greater than one joint coding the first PMI and the second PMI employs 4 bits or less.