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

4-June-07 P1901_PRO_016_r0
SYMBOL NUMBER
(BIT 1)
Δ b k (BIT 1)
OUTPUT
BIT 1 (MSB)
OUTPUT
BIT 0 (LSB)
Δ b k (BIT 0, LSB)
PN GENERATOR 1
11 10 9 8 7 6 5 4 3 2 1
PN GENERATOR 0
11 10 9 8 7 6 5 4 3 2 1
SYMBOL NUMBER
(BIT 0, LSB)
Submission page 64 UPA-OPERA
XOR
Figure 19 Channel estimation symbol generation
At the beginning of each Channel estimation symbol, the registers of the PN generators shall be set with the
corresponding seed given by Table 8. So, the value to be modulated in the phase increment of the first valid
subcarrier of the OFDM symbol will be determined by the seeds and the appropriate symbol number. The
contents of the registers of the PN generators shall be updated before calculating the phase increment for each
of the next subcarriers.
Since two bits of the symbol number are XORed with the output of the PN generators, four different symbols
will be generated. These four symbols will be repeated four times to create a sixteen-symbol sequence.
Seed
PN Generator 1 0x25E
PN Generator 0 0x3C1
Table 8 PN generator seeds