Advantages of multiple estimation in the frequency-selective block fading MIMO environments

The performance of the multiple-estimation (ME) is examined in multiple-input multiple-output (MIMO) frequency-selective fading channels. The least squares (LS) technique, the shifted scaled least squares (SSLS) estimator, and the minimum mean square error (MMSE) estimator are probed in this paper. In the uniform and non-uniform power allocation, the closed form equations are obtained for total mean square error (TMSE) of the estimators. Analytical and numerical results show that the LS estimator has lower error in the case of ME than single-estimation (SE). Moreover, it is seen that the performance of SSLS and MMSE channel estimators in the ME case is better than SE particularly at high signal to noise ratios (SNRs). It is shown that for small numbers of sub-blocks used for channel estimation, the SSLS and MMSE channel estimators are better than LS. For large numbers of sub-blocks, inversely, the LS channel estimator is better than SSLS and MMSE. The un-equal power allocation is also examined analytically and numerically. Simulation results show that exponential power allocation is proper for SSLS channel estimator in ME case.

Keywords:

Frequency selective fading , The author gratefully acknowledges the financial and other supports of this research , en , Multiple estimation , provided by the Islamic Azad University , Multiple-input multiple-output , Eslamshahr Branch , Least Squares , Tehran , Shifted scaled least squares , Iran , Minimum mean square error