Bit error probability for a M-ary QAM OFDM-based system

Results and the general expression for the bit error rate (BER) of M-ary QAM for single carrier systems are well known, but are not readily available for M-ary QAM combined with orthogonal frequency division multiplexing (OFDM). In this paper, a generalized closed-form BER expression of M-ary QAM OFDM is empirically derived and verified in the presence of additive white Gaussian noise (AWGN), using a Monte Carlo simulation. Theoretical BER graphs up to 1024-QAM over up to 256 subchannels are also presented.