Multi-H Phase-Coded Modulations with Asymmetric Modulation Indexes

Multi-h phase-coded modulation (MHPM) is a bandwidth efficient modulation scheme which offers substantial coding gain over conventional digital modulations. In this paper, a new concept of MHPM with asymmetric modulation indices corresponding to the bipolar data +1 and -1 is considered, and numerical results of the minimum Euclidean distances for such asymmetric binary multi-h schemes are provided. It is shown that performance improvements on the error probability are gained over conventional MHPM with essentially the same bandwidth and a very slight modification in implementation. The upper bounds of error probabilities as functions of observation intervals and received Eb/N0 are also investigated in detail.