Header Info Data (MB-OFDM)
trace provides information on the Header part of the MB-OFDM Orthogonal Frequency Division Multiplexing: OFDM employs multiple overlapping radio frequency carriers, each operating at a carefully chosen frequency that is Orthogonal to the others, to produce a transmission scheme that supports higher bit rates due to parallel channel operation. OFDM is an alternative tranmission scheme to DSSS and FHSS. packet.
The following results are fields in the header:
- Rate (PLCP Physical layer convergence protocol Data Rate) is the same as the Data Rate parameter in the Format tab of the Demod Properties.
- Length (PSDU 1) PHY Service Data Unit, or 2) PLCP SDU (payload) length) is an unsigned 12-bit integer that indicates the number of octets in the frame payload (which does not include the FCS Frame check sequence, tail bits, or pad bits) as defined in the standard. (See About Opt BHB: Multiband-OFDM.)
- Scrmbllnit (Scrambler Initialization) is a two-bit value that corresponds to the seed value chosen for the data scrambler as defined in the standard. (See About Opt BHB: Multiband-OFDM.)
- BurstMode (Burst Mode) is the bit set to indicate
whether the next packet is part of a packet burst (for example, a burst
mode transmission) as defined in the standard. (See About
Opt BHB: Multiband-OFDM.)
Burst Mode bit
Next Packet Status
0
Next packet is not part of the burst.
1
Next packet is part of the burst.
- PreambType (Preamble Type) is the type of preamble: Standard or Burst. When the Preamble Type parameter is set to Auto, PreamType will show the detected preamble type. Otherwise, PreamType shows the current Preamble Type parameter setting.
- TxTFC is the TFC Transport Format Combination used at the Transmitter field for the current packet as defined in the standard. (See About Opt BHB: Multiband-OFDM.) This is the same as Time Frequency Code parameter on the Format Tab of the MB-OFDM Demod Properties.
- BandGroupLSB is the least significant bit (LSB Least Significant Bit: In a binary coding scheme, the bit having the least numerical value. Analogous to the units position in a decimal number.)
of the band group used at the transmitter for the current packet as defined
in the standard. (See About Opt BHB:
Multiband-OFDM.)
Band Group
Band Group LSB
1, 3, 5
1
2, 4, 6
0
- HCS (Header Check Sequence) is used to determine if the header has been decoded correctly. The status will be reported as OK or Failed.
- R-S Parity (Reed-Solomon Parity check) is added in order to improve the robustness of the PLCP header as defined in the standard. (See About Opt BHB: Multiband-OFDM.). The status will be reported as OK or Failed.
- The decoded header bits allow the "unused" header bits to be examined for conformance to the specification.
See Also
Available Trace Data (MB-OFDM)
