Performance Bound for Generalized M-QAM Constellations in Time-Discrete Multipath Rayleigh Fading Channels with Channel Estimation Errors

In this paper we derive a lower bound on the bit error rate (BER) for the individual bit streams that can be mapped simultaneously in an hierarchical way onto generalized multilevel quadrature amplitude modulations (M-QAM). The expressions are valid for time-discrete multipath Rayleigh fading environments with imperfect channel estimation and can be regarded as an extension of the well-known matched filter bound (MFB).