SymClkErr (802.16 OFDMA)

SymClkErr (Symbol Clock Error) is the symbol clock frequency error, which is the difference between the ideal and actual symbol clock frequency in ppm. A symbol clock frequency that is less than ideal will make the OFDMA symbol time take longer than required and cause the OFDMA subcarrier spacing to decrease. A symbol clock frequency that is greater than ideal will make the symbol times take less time than required and cause the OFDMA subcarrier spacing to increase. In either case this creates subcarrier interference and increases the signal's RCE Relative Constellation Error is the RMS level of the Error Vector Magnitude, averaged over all subcarriers and all detected OFDM symbols. (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.). The resultant error value is a unitless fraction, which is multiplied by 1,000,000 to obtain SymClkErr in ppm.