Fast decoding of the hexagonal lattice with applications to power efficient multi-level modulation systems

The hexagonal lattice is important for many signal processing problems in 2-D space. In particular, it was known in the early 60´s that the lattice is asymptotically optimal for 2-D signal constellation. However, in the past three decades, most modem designers believed that the honeycomb constellation (HC) is impractical. One main difficulty is its complicated data decision operations. A fast decoding algorithm for the hexagonal lattice is proposed, so that the resultant HC demodulator is much simpler than the existing ones