A Baseband Transceiver for IEEE 802.16e-2005 MIMO-OFDMA Uplink Communications

In this paper, a 2times2 multiple-input multiple-output- orthogonal frequency division multiple access (MIMO-OFDMA) uplink transceiver based on IEEE 802.16e-2005 standard is proposed. Carrier frequency offset (CFO) and multipath channel impairments are considered. To mitigate the CFO problems in multiuser environment, an inter-carrier-interference- cancellation-based (ICI-cancellation-based) CFO estimator is proposed. The proposed CFO estimator measures energy dispersion of data compensated by ICI cancellation and channel equalization. With measured energy dispersion, correct CFOs can be obtained by running an iterative search. Compared with other designs, the proposed CFO estimator is more robust in transmission conditions and types of subcarrier allocations. Simulation results demonstrate that the proposed transceiver outperforms others in mean-square-error (MSE) and bit-error- rate (BER) performance.