BER Analysis of STBC-OFDM Wireless Systems with RF Impairments and Imperfect Channel Estimation with Application to IEEE 802.16e

In this paper, we investigate the effects of RF impairments and imperfect channel estimation (ICE) on the performance of Orthogonal Frequency Division Multiplexing (OFDM) wireless systems with transmit diversity for Space-Time Block Codes (STBC) employing N_t : N_t isin [2,3,4] transmit antennas and one receive antenna in a Rayleigh fading environment. The bit error rate (BER) expressions of the OSTBC-OFDM system is derived for each transmit-receive antenna configuration in the presence of phase noise and channel estimation errors. With emphasis on complex signal constellations, we further investigate the effect of doppler on the performance of OSTBC- OFDM for different code rates R : 1/2 les R les 1, including maximal-rate OSTBC codes. To illustrate the extent of system degradation due to these impairments on a proposed practical system, the presented results are verified through simulations by making use of the system parameters from the IEEE802.16e standard.