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

Claim 7:
8. The communication device of claim 1, wherein the explicit CSI comprises a delay-domain CSI for the higher-order singular-value matrix ŪS, and wherein the processor is configured to
calculate a reduced-sized delay-domain higher-order singular-matrix ŨS from the frequency-domain higher-order singular-matrix ŪS, wherein the delay-domain higher-order singular-matrix is given by

ŪS≈FSŨS,

where
FS∈S×L contains L vectors of size S×1, selected from a discrete Fourier transform, DFT, codebook Ω, the size of the compressed delay-domain matrix ŨS is given by L×r3, and L is the number of delays, and
the oversampled codebook matrix is given by Ω=[d0, d1, . . . , dSOf−1], where di=, [
     
      1
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          (
          
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     ]
    
    T
   
   ∈
   
    ℂ
    
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  ,
  
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    {
    
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  ,, and Of∈{1,2,3, . . . } denotes the oversampling factor of the DFT-codebook matrix;
quantize the coefficients in vectors ŨS=[ũS,1, . . . , ũS,r3]∈L×r3 using a codebook approach;
report to the transmitter the explicit CSI comprising the coefficients of ŨS instead of ŪS, along with the L delays, represented by a set of indices that correspond to the selected DFT-vectors in the codebook Ω.