Title :
Mismatched source transition probability matrix for adaptive MAP decoding in MPEG-4 imagery wireless transmission systems
Author :
Mahapakulchai, Srijidtra ; Charoenlarpnopparut, Chalie ; Hasajitto, Siriwat
Author_Institution :
Dept. of Electr. Eng., Kasetsart Univ., Bangkok, Thailand
Abstract :
Here, we design the efficient technique of transmitting the source transition probability matrix (STPM) by accompanied with the lowest frequency subband (LFS). The entries of this stochastic matrix are adaptively computed by applying the first order Markov model with MPEG-4 zerotree sequences. Because of channel disturbances, we obtain the mismatched STPM at the ML-Viterbi receiver and then employ it for newly computed branch metrics at the MAP source-controlled channel decoder. For analysis, we also evaluate the residual redundancies for both the ¿Lena¿ and the ¿Barbara¿ images. The system performance is summarized in term of both PSNR (dB) and WER for three types of slow flat Rician fading channels. In the mismatched STPM simulation results, we still obtain the most PSNR improvement of about 0.14 dB.
Keywords :
Markov processes; Rician channels; adaptive decoding; combined source-channel coding; image coding; matrix algebra; maximum likelihood decoding; multimedia communication; MAP source-controlled channel decoder; ML-Viterbi receiver; MPEG-4 imagery wireless transmission systems; MPEG-4 zerotree sequences; PSNR improvement; adaptive MAP decoding; first order Markov model; lowest frequency subband; mismatched source transition probability matrix; slow flat Rician fading channels; stochastic matrix; Cyclic redundancy check; Decoding; Discrete wavelet transforms; Frequency; Image coding; MPEG 4 Standard; PSNR; Quantization; Stochastic processes; Wavelet coefficients; Joint source-channel coding; MAP decoder; Markov model; Residual redundancy; Rician fading channels; Ring convolutional codes;
Conference_Titel :
Personal, Indoor and Mobile Radio Communications, 2009 IEEE 20th International Symposium on
Conference_Location :
Tokyo
Print_ISBN :
978-1-4244-5122-7
Electronic_ISBN :
978-1-4244-5123-4
DOI :
10.1109/PIMRC.2009.5450029