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

4-June-07 P1901_PRO_016_r0
3.1 OVERVIEW
The diagram in Figure 3 shows an example PHY layer of a transmitter.
On the transmitter side, the PHY layer receives its inputs from the Media Access Control Layer. Two separate
bit streams are shown because of the different encoding for data and control information. The delimiters shall be
interleaved by the Control Interleaving block and mapped by the HURTO Mapping block; while the data stream
shall be mapped using the HURTO Mapping block or the Adaptive Mapping block, depending on the reliability
level required for the transmission. The outputs of both Mapping blocks lead into the Scrambler, which is
followed by 4D-TCM (Four Dimensional Trellis Coded Modulation) encoding. The next step is the OFDM
Modulation, which is composed of the Subcarrier Modulator, the IDFT (Inverse Discrete Fourier Transform),
the Cyclic Prefix generator and the symbol windowing operation structure. The resulting digital signal is
converted to an analog signal by means of a DAC and IQ modulated, before passing to the amplifying and
filtering stages.
Delimiters
Data
payload
CRC
Data
Reed-Solomon
Encoder
Control
Reed-Solomon
Encoder
Control
Interleaving
3.2 PHY LAYER FRAME
Adaptive
Mapping
HURTO
Mapping
Subcarrier
Cyclic
Scrambler 4D TCM
IDFT
Window
Modulator
Prefix
Power Line
Figure 3 Transmission PHY layer
Figure 4 shows the symbols that are transmitted in a PPDU.
Submission page 37 UPA-OPERA
DAC
IQ mod
Amplifiers
Filters