Lattice filter-based frequency-domain equalizer with multiple frequency offset compensation for MIMO SDMA OFDM systems

Inhalt:
MIMO OFDM (multiple-input multiple-output - orthogonal frequency division multiplexing) systems with SDMA (space division multiple access) is a promising technique for today’s and future wireless communication. However, it is very sensitive to carrier frequency offset (CFO), which results in loosing the orthogonality between the subcarriers. Particularly, multiple users result in a multiple CFO problem which is hard to handle. In this paper, a new approach for frequency-domain equalization, named MIMO lattice equalization with multiple CFO compensation is presented on the basis of SDMA-based MIMO OFDM uplink transmission [1]. The benefits of the presented CFO compensation and equalization algorithm is a flexible allocation of computational complexity. The computational effort and the performance of the MIMO lattice equalizer will be compared with the MMSE (minimum-mean-square-error) equalizer from literature [2].