DemodOFDMSubcarStrt
This is a Data Header variable.
Type = Long
DemodOFDMSubcarStrt value is the first subcarrier index represented in the data. For 802.11a and HiperLan/2 data, the first used subcarrier index is always -26, because the subcarriers are numbered -26 to +26.
This variable is present on all 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. measurement data that has different values for each subcarrier. This is most OFDM measurement data, including IQ Meas, IQ Ref, Error Vector Spec, Syms/Errs, and Eq Freq.
This variable is used by the display and marker code to compute the correct subcarrier number to annotate the display.