Channel Estimation for Secure OFDM System using Adaptive Cyclic Prefix Selection

In order to generate blocks, Orthogonal Frequency Division Multiplexing (OFDM) uses a variety of guard intervals, including Cyclic Prefix (CP), Zero Padding (ZP), Unique Word (UW) and Known Symbol Padding (KSP). CP varies depending on the block. These guard intervals allow channel estimation, synchronization and the removal of Interblock Interference (IBI) efficiently than the ZP, UW and the KSP. In this work, the adaptive cyclic prefix based on OFDM wireless channel randomness is suggested for OFDM to fulfil the user demands, which has the ability to supply digital information in an effective and conventional methods. It is possible to minimize peak to average power ratio (PAPR) by utilizing idle subcarriers Fast Fourier Transform/ Inverse Fast Fourier Transform (FFT/IFFT) operation, due to the linearity of Inverse Fast Fourier transform in the OFDM system as well as the mismatch between subcarriers as well as Fourier points. OFDM is proposed in this work, owing to its capability of high-rate data transmission with effective bandwidth utilization and immunity to frequency selective fading channels. As a results, the proposed technique is evaluated using MATLAB simulation and the proposed methodology attains low Bit Error Rate (BER) when compared to the existing methods.