Frequency Selective MIMO precoding in Time Domain

The paper discusses methods of MIMO wireless channel precoder design (beamforming vector). Both the receiver and the transmitter have multiple antennas. Increasing antenna number of MIMO system is following to complicate procedure of precoders design. Many recent studies are aimed to find efficient precoding algorithm in term of low computational complexity for wide band transmission. Beamforming vector is calculated in frequency domain per each independent sub-band in order to utilize frequency division duplexing for OFDM based MIMO communication system. The representation of channel measurements in time domain is more compact than in frequency domain. This property is used in the proposed algorithm. The article presents algorithm (without significant loss of spatial efficiency) beamforming vectors design based on the it's calculation by selected channel impulse response taps. The proposed algorithm has a large potential in the computational complexity reduction of ordinary approach and achieves gain up to 35%.