Bit Mapping of Triangular Quadrature Amplitude Modulation

The triangular quadrature amplitude modulation (TQAM) is a newly designed signal set which has a power gain over the widely used square quadrature amplitude modulation (SQAM) and maintains low detection complexity. In this paper, we propose an optimum bit mapping for the TQAM minimizing bit errors. We also suggest a lower bound of Gray coding penalty which can be used as a measure of suboptimum bit mapping. The performance of the proposed bit mapping is shown by approximate analysis and simulation.