A new principle for circular APSK constellation optimization

In this paper, the symbol error rate for circular Amplitude-and-Phase Shift Keying (APSK) modulation in linear additive white Gaussian noise (AWGN) channel was theoretical evaluated and a new principle for optimal constellation design was proposed. The new principle can maximize the normalized Euclidean distance and reduce the variation between inter-ring and intra-ring distances for high level M-ary APSK modulation. The simulation results showed that the proposed optimal constellation can achieve lower symbol error rate (SER) than the Quadrature Amplitude Modulation (QAM) constellation.