Improve the Performance of OFDM Based Wave by Applying A Series of Sequential Levels of Encryption / Decryption

Abstract

The orthogonal frequency division multiplexing (OFDM) has been adopted as the downlink transmission scheme for the Long-Term Evolution (LTE) and is also used for several other radio technologies, e.g. WiMAX and the DVB broadcast technologies. The conventional OFDM depends on Fourier transform is called FFT based OFDM. The FFT based OFDM have a drawbacks of high PAPR and consuming bandwidth by inserting cyclic prefix. This paper uses a wavelet based OFDM instead of FFT based OFDM to solve its problem. This paper uses series concatenated encoder/decoder levels of hamming and convolutional encoder as a channel codding technique to improve the system performance.