Optimal Audio Transmission Over Error-Prone Wireless Links

In this paper, we present an optimization framework for transmitting high quality audio sequences over error-prone wireless links. Our framework introduces apparatus and technique to optimally protect a stored audio sequence transmitted over a wireless link while considering the packetization overhead of audio frames. Utilizing rate compatible punctured Reed-Solomon (RS) codes and dynamic programming, it identifies the optimal assignment of parity to audio frames according to their perceptual importance such that the segmented SNR of the received audio sequence is maximized. Our framework covers two cases. In the first case, a frame grouping technique is proposed to packetize audio frames and protect them against temporarily correlated bit errors introduced by a fading wireless channel. In this case, each packet is treated as a channel coding codeword. In the second case, a one-dimensional RS coder is applied vertically to a sequence of horizontally formed packets associated with an audio sequence in order to protect the sequence against both bit errors introduced by fading wireless channels and packet erasures introduced by network buffering. Our numerical results capture the performance advantage of our framework compared to existing techniques proposed in the literature of audio transmission. We also note that our framework can be generically applied to a variety of audio coders, making it attractive in terms of implementation.