Design of low complexity H-inf algorithm for channel estimation in multiuser multicell MIMO OFDM systems

To facilitate the increasing demand of high rate data and wireless communication requiring highest capacity, a combined technology of both MIMO (Multiple Input Multiple Output) antenna systems and OFDM (Orthogonal Frequency Division Multiplexing), called MIMO OFDM system is implemented. MIMO technology transmits signal through multiple antennas there by providing a diversity gain which enhances the capacity of communication system and OFDM provides transmission at high data rates. Thus MIMO OFDM serves the technology for current and future high speed, high capacity broadband wireless communication. Knowledge of the CSI (Channel State Information) at the transmitter and receiver has an important part in the MIMO OFDM communication. Thus obtaining channel state information (CSI), called as channel estimation, is the main challenge of MIMO OFDM systems. This work undergoes the study of the classical channel estimation algorithms such as Least Square estimation (LSE), Minimum Mean Square Error Estimation (MMSE) and new H-inf estimators. This work also focuses on the design of a new reduced complexity H-inf estimator. The reduced complexity H-inf estimator is analysed analytically and its performance is simulated. The simulation results show that it can be used to replace the existing complex algorithms effectively.