Desempenho da Compressão de Imagens pra Transmissão de Imagens em Canais HF

Transmission in high-frequency (HF) is an alternative to high range and low cost systems, as image transmission in surveillance systems. Due to the effects of this channel in the transmitted signals and its low bandwidth, it is necessary to both use techniques to protect the transmitted signal (equalization , error control coding, etc.) and signal compression to reduce the representation of the source. In previous work, for image transmission in HF channels it was proposed the use of discrete wavelet transform and vector quantization, whose dictionary vectors must be directly mapped in points of a signal constellation. In this work we extend this work by using a more appropriated modulation to the HF channel and a specially projected dictionary. The modification here proposed has good results compared to other dictionary topology in low signal-to-noise situations.