Improved CFO Synchronization of Dual-Polarized OFDM Systems using Training Symbols

In 5G and next-generation communications systems, as well as at wireless transmission using millimeter waves, dual polarization systems have gained recent interest. This paper presents carrier frequency offset (CFO) synchronization technique for Dual-Polarized Orthogonal Frequency Division Multiplex (DP-OFDM) based on the transmission of training symbols. The derived techniques lead to enhancing in performance in terms of variance of estimator against classic single-polarized (SP) complex version by using the same radiated power for fair comparisons. The synchronization technique and the Cramér- Rao lower bound are derived using quaternion algebra, which prove and corroborate along with simulations to the observed improvement in performance.