This paper focuses on the uplink of multicell IEEE 802.16-d WiMax systems with OFDM modulation and antenna array at the base stations. We propose an analytical framework to assess the average error probability of all the different transmission modes over space-time dispersive Rayleigh fading channels. The proposed method takes into account the effects of the multilevel modulation, the error correction capability of the concatenated code, the interleaving scheme, the power-angle structure of the inter-cell interference and the array processing at the base station. Simulation results corroborate the proposed analysis for a IEEE 802.16-d cellular system over different propagation scenarios.