• Bit Error Rate (BER): BER is one of the most important ways to identify the quality of the digital transmission systems. It defines the number of error bits in total data slot over an interval of time. BER is calculated as the number of error bits divided by the total number of bits sent.
• Error vector magnitude: EVM describes how far is the actual received symbol from the ideal symbol location after decimating the recovered waveform at the demodulator. The following equation is used to determine the EVM of N demodulated symbols [15].
• Modulation Error Ratio (MER): It is a measure of signal to noise ratio in a digitally modulated signal. It is expressed in dB. The equation for measured MER[15] is given below.
• IQ gain imbalance: IQ imbalance occurs due to digital to analog (DAC) conversion process or the inconsistencies between each of the analog mixers. It is an essential parameter because even a few dB can cause the improper demodulation of the signal for higher rate modulation scheme such as 64-QAM.