Two- and one-sided MIMO channel estimation using quadriphase complementary sequences

Low-complexity and high-performance multiple-input and multiple-output (MIMO) channel estimation scheme is investigated. Pilot blocks are constructed using quadriphase complementary sequences (QCSs) which enable both one-sided (OSD) and two-sided (TSD) channel estimation (CE). And OSD-CE and TSD-CE are combined to provide improved performance in frequency-selective fast and slow fading channels and to maintain low-complexity implementations. Analytical and simulation results demonstrate the performance merits of the proposed scheme.