This paper presents two discrete cosine transform (DCT)-based pilot-symbol-aided channel estimation methods using different pilot arrangement schemes. By exploiting the properties of DCT, both proposed methods mitigate the aliasing effect introduced in discrete Fourier transform (DFT)-based channel estimation method when the multi-path fading channels have non-sample-spaced path delays. Of these two DCT-based channel estimation methods, one reduces the additive white Gaussian noise (AWGN) and inter-carrier interference (ICI) significantly by iteration, while with reasonable constraint and phase shifted pilot sequences for each transmitter antenna, the other one can achieve highly efficient and accurate estimation without sacrificing much system overhead. The computer simulation results demonstrate effectiveness of the proposed DCT-based channel estimation methods.

In this paper, we propose a spatial multiplexing and diversity joint transmit structure for MIMO-OFDM system where space-frequency block coding (SFBC) is used over all spatial multiplexing layers to obtain both space diversity and frequency diversity gain. We have derived a Monte Carlo probabilistic data association (PDA) detector to get a better bit error rate (BER) performance compared to generic PDA detector. Computer simulation results show that the proposed detector can reduce the intersymbol interference (ISI) greatly, and improve the system performance significantly while the computation complexity has been lower to a proper lever.

As a soft-input soft-output detection scheme for multiple-input multiple-output (MIMO) channels, the stochastic sequential Monte Carlo (SSMC) method generates MlMO symbol samples based on importance sampling and resampling techniques. In this paper, the MIMO system, with the SSMC detection, is incorporated with the orthogonal frequency division multiplex (OFDM) and turbo channel coding to undertake performance comparison in frequency selective fading channel. For the uncoded system, the SSMC method, whose complexity is linear with the number of transmit antennas, outperforms MMSE. Employing the SSMC method as the first-stage demodulator in the coded MIMO systems, the iterative receiver offers 1 dB performance gain at 10-3by three iterations. Computer simulation results are provided to demonstrate the performance of the proposed systems