Development of scalable video transmission using orthogonal frequency division multiplexing

Scalable Video Coding (SVC) method of compression is widely used in heterogeneous networks and needs reliable high data rate transmission technique. Orthogonal Frequency Division Multiplexing (OFDM) is widely used modulation technique over both wired and wireless channels. OFDM applications rely mainly on its ease of implementation, high data rates, and reduction of fading effects. This thesis is concerned with the study and performance evaluation of traditional OFDM based on Fast Fourier Transform (FFT-OFDM) to OFDM technique based on Discreet Wavelet Transform (DWT-OFDM). Both are used for transmission of SVC signal. A method is development to order SVC sub-layers so that the transmission bit rate of the multiplexed systems can gain further scalability which assist in providing flexible bit rate selection in addition to the scalability in quality of the received video signal. The performances of the systems are evaluated for different wireless channel models, different bandwidths, and different sub-layers selection. The most useful finding is that the proposed layered scalability for both DWT-OFDM and FFT-OFDM systems can withstand channel fading and bandwidth limitations. DWT- OFDM system performed better than FFT-OFDM over the most transmission scenarios considered here. Both systems operate successfully (BER < 10-5 for channel SNR ≥ 20dB) over channel having low fading effects, while noticeable degradation occurred with high fading levels. The proposed removing technique of sub-layers gives more flexibility and acceptable performance as compared with the original approach. The results show that the BER almost remain unchanged with different numbers of sublayer removed, while the value of peak signal to noise ratio (PSNR) dramatically changed when more enhancements sub-layers removed. The
PSNR value changed from more than 30 dB with four removed sub-layers to less than 24 dB with twelve removed sub-layers.