Implementation of Pilot Channel Estimation Techniques for OFDM System with Low Mean Square Error

Abstract

Abstract: Orthogonal Frequency Division Multiplexing(OFDM) has grown to be the most popular multi carriercommunication system in high speed data communications.The available bandwidth is utilized efficiently, and more datarates can be achieved because of orthogonal carriers in OFDMsystem. OFDM system requires precise channel estimation andsynchronization to reduce Mean Square Error (MSE). In thiswork, various Pilot Channel Estimation (PCE) techniques areused to compute CSI (Channel State Information). Pilots aretransmitted along with the data and channel response iscomputed with various interpolation techniques such as linear,spline, cubic Interpolation techniques by extracting the pilotsat the receiver. The performance metrics like Mean SquareError (MSE) and computation time are computed andcompared for different PCE techniques. Discrete FourierTransform (DFT) based channel Estimation is combined withinterpolation techniques and channel response is computed andcompared with Least Squares (LS) and Minimum MeanSquare Error (MMSE) approaches. LS, MMSE, LMMSE(Linear MMSE) methods are combined with TimeDivision(TD) and Time Division Duplexing(TDD) techniquesto compute MSE. TD-LMMSE approach achieves least MSEwith more computation time. Index Terms: OFDM, channel estimation, interpolation, CSI,MSE, computation time.