• Priyanka Shukla
• Gautam Singh

In this paper we present some findings of our research on Multiple-Input Multiple-Output (MIMO) Orthogonal Frequency Division Multiplexing (OFDM) systems based on training sequence aided channel estimation. Following the development of a linear algebraic matrix model for cyclic prefix-based MIMO OFDM systems, we will describe a generalized preamble structure which is a simple extension of preambles used in single-input single-output (SISO) OFDM so that its good properties can be preserved, such as low peak to average power ratio. We then derive the channel estimation algorithms for the least squares (LS) and the linear minimum mean squared error (LMMSE) based on the proposed preamble architecture. Just in order to minimize the duration of the preamble, we also suggest a switched subcarrier preamble scheme in which the transmitting antennas are divided into groups, and preambles are transmitted in each group in alternate subcarrier subsets. Thereafter, an LMMSE filter-based interpolation scheme and a DFT-based LS interpolation scheme will be used to obtain the channel estimates for all interested subcarriers. The filter parameters can be set in all the schemes suggested in this paper, and robust output can be obtained even when mismatched SNR and channel statistics are used in the calculation of the filter parameter.

Multiple input multiple output, orthogonal frequency division multiplexing, single input singleoutput, channel estimation, training, linear minimum mean squared error.

"MIMO OFDM’s CHANNEL ESTIMATION ASSISTED VIA A TRAINING SEQUENCE", International Journal of Emerging Technologies and Innovative Research (www.jetir.org), ISSN:2349-5162, Vol.6, Issue 5, page no.384-388, May 2019, Available :http://www.jetir.org/papers/JETIREQ06087.pdf

"MIMO OFDM’s CHANNEL ESTIMATION ASSISTED VIA A TRAINING SEQUENCE", International Journal of Emerging Technologies and Innovative Research (www.jetir.org | UGC and issn Approved), ISSN:2349-5162, Vol.6, Issue 5, page no. pp384-388, May 2019, Available at : http://www.jetir.org/papers/JETIREQ06087.pdf