Reference Preamble IQ Values (Custom OFDM)

The Reference Preamble IQ Values parameter specifies the reference values of the preamble subcarriers. Each preamble subcarrier is represented by a complex value, "I" the Real part followed by "Q" the Imaginary part, that is repeated for each subcarrier.

You can use the Load Reference Preamble IQ Values button to load a text file containing the reference preamble IQ values.

Reference Preamble I-Q File

The Preamble I-Q file The Preamble I-Q file defines the expected I and Q values for each preamble subcarrier. defines the expected I and Q values for each preamble subcarrier. This file contains I and Q values for every preamble subcarrier (Resource Type Resurce Type specifies the function of the measurement subcarriers; preamble, pilot, data, All, UserN, Unknown, or Null subcarrier 3) defined in the Resource Map file The Resource Map file defines the function of each subcarrier in each symbol, describing whether it is a preamble, pilot, data or null subcarrier.. Each time the demodulator encounters a “3” in the Resource Map file, it reads the next two values from the Preamble I-Q file and uses these values as the ideal I-Q location for that preamble subcarrier.

For more information, see "Preamble I-Q File" in the Making a Custom OFDM Measurement tutorial.