Channel estimation in MIMO OFDM systems with sparse pilot tones

In this paper, we present a low-rank channel estimation scheme for multiple-input, multiple-output orthogonal frequency division multiplexing systems using sparse pilot tones. The focus of the paper is to reduce the complexity of the channel estimation with slight degradation in the error rate performance. By using sparse pilot tones in a pilot preamble, the computational complexity is reduced by a factor roughly equal to the number of transmitting antennas. The performance of the channel estimation is presented in terms of the mean-square error (MSE) obtained from computer simulation.