A Novel Metric for ACLR of Output Signals of Power Amplifier in Multicarrier Systems

One of the main drawbacks of multi-carrier signals is the large envelope fluctuations. When multi-carrier signals with large envelopes pass through a power amplifier (PA), a degradation of adjacent channel leakage ratio (ACLR) happens. There exist two metrics commonly utilized to describe the envelope fluctuations of multi-carrier signals, i.e., peak-to-average power ratio (PAPR) and cubic metric (CM). However, our research shows that these two metrics cannot indicate the degradation of ACLR sufficiently accurately. In this paper, we study the Volterra-series-based PA model and sufficiently analyze the distortion caused by the nonlinearity and memory effect of PA. Base on this analysis, a novel metric of signal envelope fluctuations is proposed. The simulation results demonstrate that, compared with PAPR and CM, the new metric is more accurate to indicate the ACLR of output signals of PA.