Patent ID: 11876589
Assignee: FRAUNHOFER GESELLSCHAFT ZUR FÖRDERUNG DER ANGEWANDTEN FORSCHUNG E.V.
Field: Telecommunications (Electrical engineering)
Classification: CPC H | IPC H

Claim 8:
9. The communication device of claim 1, wherein the explicit CSI comprises a Doppler-frequency domain CSI for the higher-order singular-value matrices ŪD, and wherein the processor is configured to
calculate a reduced-sized Doppler-frequency domain higher-order singular-matrix ŨD from the time-domain higher-order singular-matrix ŪD, wherein the Doppler-frequency domain higher-order singular-matrix is given by

ŪD≈FDŨD,

where
FD∈D×G contains G vectors of size D×1, selected from a discrete Fourier transform, DFT, codebook Ω, the size of the compressed Doppler-frequency domain matrix ŨD is given by G×r4, and G is the number of Doppler-frequency components, and
the oversampled codebook matrix is given by Ω=[d0, d1, . . . , dDOt−1], where, d
    i
   
   =
   
    
     
      
       [
       
        1
        ⁢
           
        
         e
         
          
           
            -
            j
           
           ⁢
           2
           ⁢
           π
           ⁢
           i
          
          
           
            o
            t
           
           ⁢
           D
          
         
        
        ⁢
        …
        ⁢
            
        
         e
         
          
           
            -
            j
           
           ⁢
           2
           ⁢
           π
           ⁢
           
            i
            ⁡
            (
            
             D
             -
             1
            
            )
           
          
          
           
            o
            t
           
           ⁢
           D
          
         
        
       
       ]
      
      T
     
     ∈
    
    ⁢
    
     ℂ
     
      D
      ×
      1
     
    
   
  
  ,
  
   i
   ∈
   
    {
    
     0
     ,
      
     …
       
     ,
     
      
       
        O
        t
       
       ⁢
       D
      
      -
      1
     
    
    }
   
  
  ,, and Ot∈{1,2,3, . . . }denotes the oversampling factor of the DFT-codebook matrix;
quantize the coefficients in vectors ŨD[ũD,1, . . . , ũD,r4]∈G×r4 using a codebook approach; or
report to the transmitter the explicit CSI report comprising the coefficients of ŨD instead of ŪD, along with the G Doppler-frequency components, represented by a set of indices that correspond to the selected DFT-vectors in the codebook Ω.