Channel Estimation Based on LMS in Orthogonal Wavelet Packet Division Multiplexing

In Orthogonal Frequency Division Multiplexing (OFDM), Fourier Transform (FT) is used as a modulation technique. To avoid Inter-symbol Interference (ISI) in OFDM by a time dispersive channel, a Cycle Prefix (CP) is used which also reduces its spectral efficiency. Discrete Wavelet Packet Transform (DWPT) as a modulation scheme has been proposed for wireless communication. In this paper, DWPT based OFDM is presented and proposed using Least Mean Square (LMS) algorithm for channel estimation. The dual-tree complex is used for OWPDM. Channel estimation is major factor in wavelets. LMS is proposed for OWPDM based on DWPT and compared with Minimum Mean Square Error (MMSE) algorithm and Least Square (LS) algorithm. The performance is measured in the multipath frequency selective fading channel. Simulation results show a clear improvement in Bit Error Rate (BER) for LMS over MMSE and LS.