A Review on Optimized Transmission of Images with OFDM over AWGN Channel Using Trigonometric Transforms

In this paper a scheme is proposed for optimized transmission of images over AWGN (Additive White Gaussian Noise) channel with OFDM (Orthogonal Frequency Division Multiplexing) a popular technique in high speed wireless communications. The Low Density Parity Check Coding (LDPC) with coded OFDM is used to improve the BER performance. The Set Partitioning in Hierarchical Trees (SPIHT) algorithm is used for source coding of the images to be transmitted. In this scheme the transmit data sequence of the OFDM signal after Inverse Fast Fourier Transform (IFFT) is grouped into in-phase and in-quadrature components, then each component is transformed using either the Discrete Cosine Transform (DCT) or the Discrete Sine Transform (DST). The main obstacle is the high peak-to-average power ratio (PAPR) in the OFDM system causing non-linearity at the receiving end. This paper focuses on the fact that, on comparing with the other means, the proposed method greatly reduces the PAPR of the OFDM signal.