Robust Audio Coding Over Wireless Channels

In this paper, a concatenated system combining turbo product codes and convolutional codes with soft decision Viterbi decoding algorithm and diversity is proposed to enhance the robustness of unequal error protection (UEP) scheme for wireless transmission of MPEG-4 advanced audio coding. The proposed scheme has been tested over the Gaussian and Rician fading channels. Under severe channels with random, burst and mixed bit error rates (BER) of 6.00 times 10^-2 and above, the proposed scheme provides a 90% improvement in residual BER performance, which is approximately 3 dB, with 19% increase in bandwidth over the original UEP scheme. At a high channel BER of 6.00 times 10 ^-2, the proposed scheme gives an error-free header frame. Compared with the concatenated convolutional codes, the proposed scheme provides 0.5 dB BER performance improvements with the same bandwidth. With diversity, the performance can be further improved by 3 dB at low SNR for the proposed scheme