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

4-June-07 P1901_PRO_016_r0
Where:
Equation 19
• k is the time index representing the k-th OFDM symbol. Index 0 corresponds to the channel reference
symbol (see 3.8.1).
• s k is the modulator output for a given subcarrier.
• λ is the factor to normalize the constellation to unit power:
λ =
A
2
+
⎛ 2N
−1⎞
( N −1)
⎜ A + ⎟
⎝ 6 ⎠
Submission page 56 UPA-OPERA
1
Equation 20
• a k , ak ∈{ 0, 1,
Κ , N −1}
, represents the information coded in the amplitude, as supplied by the
constellation encoder (see 3.5.4).
• θ k stands for the absolute phase of the modulated signal obtained as follows:
( θ ( 2π
k 1 ) bk
) mod π
+
θ k
2
M Δ
= −
Equation 21
Equation 21 applies for k>0 only. bk
Δbk ∈ 0, 1,
Κ , M −1
, represents the information coded in the
phase increment, as supplied by the constellation encoder (see 3.5.4).
Δ , { }
A is a shaping parameter and represents the ring offset from the centre of the constellation.
Parameters M, N and A are determined by the number of bits per subcarrier indicated by the bit-loading table
according to Table 6.
Bit-loading Constellation M N A Bits coded in the Bits coded in