Ch Frequency Response (802.16 OFDMA)
shows the equalizer channel frequency response, which is the reciprocal of the FFT Fast Fourier Transform: A mathematical operation performed on a time-domain signal to yield the individual spectral components that constitute the signal. See Spectrum. of the Eq Impulse Response. has one point per subcarrier. is the measured equalizer frequency response for the analyzed signal. It contains one complex value for each subcarrier, plus an interpolated value at the middle unused subcarrier. The total number of subcarriers is dependent on the and type (e.g. analysis for a signal with will have a total of 841 values).
For measurements, the equalizer frequency response is estimated in one of three methods:
- Preamble only: uses the Channel Estimation Sequence in the preamble of the OFDMA burst.
- Preamble, pilots and data: uses the entire OFDMA burst, including the Channel Estimation Sequence (contained in the preamble), the Data symbols, and Pilot symbols..
- Preamble and pilots: uses the entire OFDMA burst, including the Channel Estimation Sequence (contained in the preamble) and the Pilot symbols.
For measurements, the equalizer frequency response is estimated in one of three methods:
- Pilots and data: uses the entire OFDMA burst, including the Data symbols and Pilot symbols.
- Pilots only: uses the entire OFDMA uplink subframe,
including only the Pilot symbols.
When the channel estimation contains unused subcarriers, the is linearly interpolated (magnitude and phase interpolation) between the used subcarriers in the channel estimation.
When the measurement parameter Include Inactive Antenna Paths on MIMO Traces is selected, the trace displays overlays of all antenna paths, regardless of how low in power they are. When the measurement parameter is not selected, the trace displays only the results of active antenna paths.
See Also
