Achievable Error-Rate Analysis of OFDM Communication Systems Incorporating MRC Diversity Technique over Correlated Nakagami-m Fading Channels

Abstract

For the purpose of more effectively investigating the bit error-rate (BER) and symbol error-rate (SER) performances achieved by orthogonal frequency division multiplexing (OFDM) communication systems employing maximal-ratio combining (MRC) receiver architecture, concise closed-form asymptotic BER and SER formulas are derived over correlated Nakagami-m fading channels. By utilizing the proposed simple asymptotic BER and SER expressions, explicit insights into the achievable error-rate performance (i.e., modulation gain and diversity order) can be also obtained for the various modulation schemes and channel conditions, particularly in the high signal-to-noise ratio (SNR) regime. To be specific, we derive the exact expressions of the modulation gain obtained from the L-branch MRC OFDM systems with binary signals and M-ary quadrature amplitude modulation (MQAM) schemes, and also show that the full diversity of order mL can be asymptotically achieved even in correlated Nakagami-m fading environments.