Multipulse PPM on memoryless channels

We examine several properties of n-pulse pulse position modulation (PPM) [H. Sugiyama et al., 1989] on memoryless channels. We derive the maximum likelihood decision rule and an exact expression for the symbol error rate for nges1, generalizing previous results [R.M. Gagliardi et al., 1976, M. Simon et al., 2003]. A capacity comparison indicates that muItipulse PPM does not produce appreciable gains over conventional PPM except at high average power