Research On Channel Estimation Technology In OFDM Systems

This paper mainly focuses on the algorithms for channel estimation in OFDM system. It also simulates and analyzes by computer.At first, the properties of the wireless fading channel, the principles of the OFDM systems, the traditional channel estimation algorithms based on pilot assisted and blind channel estimation are introduced briefly. Secondly, for the tradeoff between performance and complexity, the algorithm by using Wiener filtering combined with interpolation filtering are proposed. The singular value decomposition method is used to reduce the complexity of this novel algorithm. Aiming at the deficiencies of low estimation precision, high complexity and slow convergence speed etc. in the traditional blind channel estimation method. An Expectation-Maximization (EM) based semi-blind channel estimation algorithm is proposedFinally, the performance of these algorithms is analyzed and compared by computer simulation.