MAP Source-Controlled Channel Decoding with Interleavers for MPEG-4 Image Indoor Wireless Transmission Systems

The Performance Evaluation of Recon_Gurable Random Interleavers with MAP Decoding for MPEG-4Medical Image Transmission Systems over Indoor Wireless Channels

“…To reduce the computation of interleaving process, we do not generate the matrix P. Instead, we find the location of deinterleaved data by searching for the location of number 0,1,…,m-1 in the random sequence. In our previous work [12], we observe the significant improvement of system performance when the size of random interleaver is assigned to the whole packet length. The experiment is done for the famous "Lena" image transmitted over the Rician block-fading channels.…”

“…For a noiseless channel, the peak signal to noise ratio (PSNR) of the reconstructed image and its compression ratio is 28.493 dB and 17:1, respectively. For the system channel encoder, we select the 32-state polynomial ring convolutional encoder from our previous work [9] and [12]. Turning to interleaving process, we implement the reconfigurable random interleavers with the variable size of N r = 32, 64, 128 and 143.…”

Mismatched source transition probability matrix for adaptive MAP decoding in MPEG-4 imagery wireless transmission systems

“…For a noiseless channel, the peak signal to noise ratio (PSNR) of the reconstructed "Lena" and " Barbara" images with their compression ratio are 27.436 dB with 28:1, and also 31.832 with 31:1, respectively. For the system channel encoder, we choose our designed 32-state polynomial ring convolutional encoder from our previous work [16] and [17]. Table I summarizes the average word error rates (WER) and PSNR for the Rician fading channels with γ = −43 dB, -33 dB and -23 dB, respectively.…”