Page 791 - 5G Basics - Core Network Aspects

Transport aspects 2

For example, as depicted in Figure 10-19, the first VF sample component, having the 11-bit two's
complement representation 11110010101, has shortest representation 10010101 and hence its scale is
s1 = 7. Likewise, the second component 00000010010 has shortest representation 010010 and hence its
scale is s2 = 5.

The FTU-R then computes for each block a data-dependent block scale parameter S = maxec(sec), where the
maximization index ec runs over all 2×F_block VF sample components in the block.

For example, as depicted in Figure 10-19, F_block = 1 and the block scale parameter S is the maximum of s1
and s2, hence S = 7.
If padding = 0, for each block in the given vectored band, the FTU-R shall set:

B _ M  max( S , B _ min), B  L  max( B _ M  L _ w  , 1 B _ min) (10-1)
In this case, the final reported VF sample components are:

 
_
r _ x  max  2 B _ M B L _ ,min R q x 2 B _ M B L _  2  B _ M ,2 B _ M B L _  1 

 
r _ y  max  2 B _ M B L _ ,min R q y 2 B _ M B L _  2  B _ M ,2 B _M B L _  1 
_

R
where    is the rounding half-up function if rounding=1 or the floor function if rounding=0
 floor (x  5.0 ) rounding 1
R  x 
 floor (x ) rounding  0
If padding = 1, for each block in all the vectored bands, the FTU-R shall set:

either B _ M  max( S , L _ w  ) 2 , 1 (sign extension) or B _ M  max( ) 2 , S (zero padding);
and

B _ L  B _ M  L _ w  1 (with bits set to 0 for bit indices < 0). (10-2)
In the case of sign extension with S  L _ w 1, and the case with zero padding, the final reported VF

sample components are:

 
_
r _ x  max  2 L _ w 1 ,min R q x 2 L _ w 1  2  S ,2 L _ w 1  1 

 
_
r _ y  max  2 L _ w 1 ,min R q y 2 L _ w 1  2  S ,2 L _ w 1  1 

In the case of sign extension with S  L _ w 1, the final reported VF sample components are:


r _ x  max  2 L _ w 1 ,min R  _q x ,2 L _ w 1  1  q _ x


r _ y  max  2 L _ w 1 ,min R  _q y ,2 L _ w 1  1  q _ y

The values of the reported VF sample components shall be represented using the two's-complement
representation of L_w bits. The parameters B_M and B_L shall always satisfy the relations B_L  B_M and:

2  B_M  B_max.
Selection of zero padding or sign extension is vendor discretionary by the FTU-R. However, the FTU-R shall
not change the selection after the first report until the next initialization.

781