Link-level performance of star 32/64QAM schemes using frequency domain equalizer for DFT-precoded OFDMA

This paper presents the average block error rate (BLER) performance of star 32/64QAM schemes employing a frequency domain equalizer (FDE) with the BLER performance of the cross 32QAM or square 64QAM scheme as a reference in discrete Fourier transform (DFT)-precoded orthogonal frequency division multiple access (OFDMA). The star QAM scheme has an advantageous feature in that the fluctuation in the amplitude component is smaller than that for the cross or square QAM scheme. The feature of the paper is that we focus on the actual received signal-to-noise power ratio (SNR) taking into account a realistic peak-to-average power ratio (PAPR) measure called the cubic metric (CM) considering the non-linearity of the power amplifier. Link-level computer simulation results show that the star QAM constellation with independent bit mapping for the phase and amplitude modulations achieves a lower required average received SNR considering the CM compared to that with the minimum Euclidian distance but with composite mapping of the phase and amplitude modulations. Through extensive link-level simulations, we show the potential benefit of the star 32/64QAM schemes in terms of reducing the required average received SNR considering the CM that satisfies the target average BLER compared to the cross 32QAM or square 64QAM scheme.