Design of Sample Adaptive Product Quantizers for Noisy Channels

Z. Raza, F. Alajaji, T. Linder
2005 IEEE Transactions on Communications  
Channel-optimized vector quantization (COVQ) has proven to be an effective joint source-channel coding technique that makes the underlying quantizer robust to channel noise. Unfortunately, COVQ retains the high encoding complexity of the standard vector quantizer (VQ) for medium-to-high quantization dimensions and moderate-to-good channel conditions. A technique called sample adaptive product quantization (SAPQ) was recently introduced by Kim and Shroff to reduce the complexity of the VQ while
more » ... chieving comparable distortions. In this letter, we generalize the design of SAPQ for the case of memoryless noisy channels by optimizing the quantizer with respect to both source and channel statistics. Numerical results demonstrate that the channeloptimized SAPQ (COSAPQ) achieves comparable performance to the COVQ (within 0.2 dB), while maintaining considerably lower encoding complexity (up to half of that of COVQ) and storage requirements. Robustness of the COSAPQ system against channel mismatch is also examined. Index Terms-Channel-optimized quantization, encoding/ storage complexity, joint source-channel coding, structurally constrained vector quantization.
doi:10.1109/tcomm.2005.844938 fatcat:4y3xpilq5zchvksho5mplbppsa