5 and 7 bit/symbol 4D Modulation Formats Based on 2A8PSK

We propose 5 and 7 bit/symbol 4D modulation formats based on 2A8PSK, which outperform previously known modulation formats for each spectral efficiency. Combined with the recently reported 6 bit/symbol 2A8PSK, the 2A8PSK family covers 5-7 bits without significant hardware modifications.