Channel estimation for walsh hadamard precoded OFDM/OQAM

Orthogonal frequency division multiplexing with offset quadrature modulation (OFDM/OQAM) has many advantages over the conventional OFDM system. The precoding of the OFDM/OQAM with Walsh Hadamard transform (WHT) improves system ability to mitigate deep fades in frequency selective channels. However, the addition of the transform prevents the functionality of the existing channel estimation techniques. Therefore, this work introduces a new technique to estimate channel coefficients utilising preamble structure. The proposed preamble methods are based on different pilot distribution and enhanced pilots power. The required number of symbols for the estimation is minimized while maintaining reliable performance.