Herbert Chan

• Applied Science and Technology Research Institute

The conventional channel-optimized vector quantization (COVQ) is very powerful in the protection of vector quantization (VQ) data over noisy channels. However, it suffers from the time consuming training process. A soft decoding self-organizing map (SOM) approach for VQ over noisy channels is presented. Compared with the COVQ approach, it does not...

A self-organizing map (SOM) approach for vector quantization (VQ) over wireless channels is presented. We introduce a soft decoding SOM-based robust VQ (RVQ) approach with performance comparable to that of the conventional channel optimized VQ (COVQ) approach. In particular, our SOM approach avoids the time-consuming index assignment process in tra...

This paper studies the problem of non-binary index assignment for scalar quantizer with M-ary phase shift keying (M-PSK). An interesting observation enables us to well approximate this problem to the well-known traveling salesman problem (TSP). A unique optimum solution to the approximation is resulted. Optimality of the solution is agreed by simul...

Data transmission using self-organizing feature map (SOFM) based vector quantizer (VQ) and channel optimized vector quantizer (COVQ) with various space-time trellis codes (STTC) over wireless channels are studied. It is interesting to note that in a SOFM-STTC system, even with a weak STTC, the overall performance in terms of reconstruction error do...