Competition among Interleavers in OFDM- An Encrypted Modulated Modulation Approach

Interleaving is a process of making a system efficient by arranging its data in a noncontiguous manner. It is mostly used in wireless communication and storage systems in addition to forward error correcting codes thus enhancing their performance. The quality of digitally transmitted data over the radio fading channel is improved by this process. As every other process, interleaving has its own drawbacks. One is that it brings in time-delay, demand for higher memory and complexity. This paper presents the working and reliability of a convolutionally coded and interleaving in OFDM (Orthogonal Frequency Division Multiplexing) system that can reduce the time delay as well as memory space to a great extent. Then the interleaved outputs are encrypted to provide security to the wireless users. The interleavers used are Row, Helical, Row column and Odd even. BER(Bit Error Rate) graph is plotted among various modulation schemes such as BPSK, QPSK, 8,16,32 and 64 QAM with all four interleavers and identified which interleaver can be adopted to the particular modulation scheme to reduce BER.