This letter addresses the superimposed pilot aided multiuser channel estimation for the uplinks of multi- input multi-output orthogonal frequency-division multiplexing systems. To mitigate the embedded-data effects on the performance of channel estimation, a novel combining algorithm is proposed. Optimal pilot symbols are developed with respect to the least square channel estimate's mean square error. The averaged sum-capacity lower bound is derived and simulated. Simulation results show that on a low signal-to- noise ratio regime, our proposed scheme achieves better performance and higher capacity than the conventional pilot aided approach. scheme is developed for MIMO-OFDM uplinks. To decrease the unknown-data effects, a new signal combining algorithm is proposed. Optimal pilot symbols are derived with respect to the mean square error (MSE) of the least square (LS) channel estimate. Averaged sum capacity is resorted to find some insights on spectral efficiency. Notation: Vec(A) represents stacking the columns of matrix A. Tr(A) is the trace of matrix A. Superscripts T, *, H denote transpose, conjugate and Hermitian, respectively; ⊗ represents the Kronecker product; and IN is an N×N matrix.
[1]
Kyung Sup Kwak,et al.
Pilot-aided channel estimation for multiuser MIMO-OFDM systems
,
2005,
IEEE International Symposium on Communications and Information Technology, 2005. ISCIT 2005..
[2]
Jitendra K. Tugnait,et al.
On channel estimation using superimposed training and first-order statistics
,
2003,
IEEE Communications Letters.
[3]
Ananthram Swami,et al.
Channel estimation and symbol detection for block transmission using data-dependent superimposed training
,
2005,
IEEE Signal Processing Letters.
[4]
Liuqing Yang,et al.
Optimal training for MIMO frequency-selective fading channels
,
2005,
IEEE Transactions on Wireless Communications.