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

4-June-07 P1901_PRO_016_r0
x = 0 y =
0
Table 3 Bit extraction
z ' = z + 2 = x + y + 1
Bit extraction not necessary, no message bits
being sent
Since the maximum number of bits in a group will be 19, a 19 bits wide word called t´ will be formed from each
two subcarriers, filling most significant bits with zeroes when z´ < 19. This word will be scrambled with a
pseudorandom word generator.
The bits per symbol (BPS) is defined by:
3.5.2 Scrambling
BPS = ∑ z
i
∀i
∈ Symbol
Submission page 50 UPA-OPERA
i
Equation 17
Each of the bits from the pseudorandom generator shall be generated with the same polynomial structure
initialized with different seeds for each bit (where bit 0 is the least significant bit).
The pseudorandom sequence generator shall be the 10-bit PN generator with characteristic polynomial given by
Equation 18.
( x)
f = +
3 10
1+ x x
Equation 18
At the beginning of each symbol, the registers of the PN generators shall be set with the corresponding seeds
given by Table 4
PN Seed