Approximation of Spatial Spectrum by Discrete Fourier Transform in MIMO-OFDM System

The paper considers approximation of spatial spectrum of the channel using the steering vector approach under the precoder spatial filter by discrete Fourier transform (DFT). We provide the independence of the geometry of our spatial spectrum on polarization for each user equipment (UE) antenna through the propagation channel. The beamforming allows to approximate spatial spectrum by 1D DFT used precoding techniques in such system as multiple-input multiple-output (MIMO). The obtained simulations show the degradation of error probability with decreasing order of approximation beams. Benefit performance of impact the approximation precoding algorithms of bit error rate (BER) to signal to noise ratio (SNR) provide from 2 to 7 dB depended on 1D DFT order.