DataRCE (802.16 OFDMA)
DataRC(dB) is the same as EVM, but excludes the pilot subcarriers. is computed in dB and as a percentage (%rms). DataRCE is necessary since measuring data bursts with few allocated subchannels leads to an EVM Error vector magnitude (EVM): A quality metric in digital communication systems. See the EVM metric in the Error Summary Table topic in each demodulator for more information on how EVM is calculated for that modulation format. dominated by pilot subcarrier EVM. DataRCE does not include "common" pilots that are not specifically associated with the data burst. This value is computed using all active data subcarriers.
When making measurements of DL Down Link (forward link: from base station to cell phone)-PUSC partial usage of subchannels: Some of the subchannels are allocated to the transmitter. data bursts that occupy fewer slots than allocated, the allocated-but-unoccupied slots will be used when computing error metrics (like DataRCE). Therefore, if many slot are unoccupied, but allocated, these metrics may include significant error power which is not present on data carrying subcarriers. This occurs automatically when an analyzed DL-PUSC data burst is detected as having allocated-but-unoccupied slots (relative to the decoded DL-MAP downlink map: A MAC message that defines burst start time for both time division multiplex and time division multiple access (TDMA) by a subscriber station (SS) on the downlink. or the user-provided zone definition).
Individual Data Burst - DataRCE results
The DataRCE results for individual data bursts are provided in the Data Burst Info summary table. The DataRCE (dB) and RCE Relative Constellation Error is the RMS level of the Error Vector Magnitude, averaged over all subcarriers and all detected OFDM symbols. (dB) results will be identical for zone types where the pilot subcarriers are not associated with specific subchannels (i.e. ). In all other zone types, where the data burst-are associated with specific subchannels (i.e. all zone types and ) associated pilot subcarriers, the RCE and DataRCE results are unique. The RCE (dB) result will include pilot subcarriers that are not included in the DataRCE (dB), see Data Burst Info summary table.
See Also
