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

4-June-07 P1901_PRO_016_r0
N W
NCP
Equation 23
Submission page 60 UPA-OPERA
N SYM
N IFFT
Figure 17 Windowing
The maximum duration of the window (Nw) depends on the symbol Type used:
• Type I: 128 samples
• Type II: 128 samples
• Type III: 64 samples
The OFDM symbol can be expressed in mathematical form as inEquation 24.
s
768
2046
⎧
⎛ j2πk
⎞
⎛ j2πk
( n)
= k SYM wSYM
( n)
⎨∑
c(
k,
i)
exp⎜
( n − N CP − N W ) ⎟ + ∑ c(
k − 510,
i)
exp⎜
( n − N
⎩ k = 1 ⎝ 2048
⎠ k = 1279
⎝ 2048
Equation 24
i
Where
− i is the i-th OFDM symbol; i = 0, 1, …
− n is the sample index; 0 ≤ n < NSYM+NW
− kSYM is a normalization factor, that shall be chosen in order to meet the PSD and modulation accuracy
requirements.
− wSYM(n) is a windowing function
− c(k,i) is the k+iNSD complex value from the subcarrier modulation block
CP
− N
W
⎞⎫
) ⎟⎬
⎠⎭