Medium Access Control (MAC) and Physical Layer (PHY) - CISE

4-June-07 P1901_PRO_016_r0
0 2
3
8
g ( x)
= ( x −α
)( x −α
)( x −α
)...( x −α
) (k0+8,k0,t=4)
1 2
3
12
g ( x)
= ( x −α
)( x −α
)( x −α
)...( x −α
) (k1+12, k1,t=6)
2 2
3
16
g ( x)
= ( x −α
)( x −α
)( x −α
)...( x −α
) (k2+16, k2,t=8)
3 2
3
20
g ( x)
= ( x −α
)( x − α )( x −α
)...( x − α )
Table 1 RS data polynomials
(k3+20, k3,t=10)
The “FEC payload” field in each burst header contains the number of 32-bit words that will be coded per RS
codeword, and therefore determines the amount of payload bytes per codeword (ki).
Maximum and minimum value for this field is given depending on the mode in Table 2:
RS data
mode
Redundancy
words
Max payload in words
Min payload in words
HURTO Adaptive
0 2 61 2 34
1 3 60 3 33
2 4 59 4 32
3 5 58 5 31
Table 2 RS data payload
Each data payload shall be coded following a different RS coding scheme that will be configured in each Burst
header. The selected coding scheme is a shortened Reed-Solomon code that can be processed as a systematic
RS(255, 255-2*ti,ti) by adding 255-(ki+2ti) bytes set to zero before the information bits. After the RS coding
procedure these null bytes shall be discarded, leading to RS codewords of n = ki+2t bytes
Submission page 43 UPA-OPERA