Decodificação de Canal em Sistemas com Transmissão Progressiva

Marcelo S. Pinho, Weiler A. Finamore

DOI: 10.14209/SBRT.2020.1570649640

Evento: XXXVIII Simpósio Brasileiro de Telecomunicações e Processamento de Sinais (SBrT2020)

Keywords: codificação de fonte com refinamento sucessivo transmissão progressiva codificação fonte-canal

Abstract

The source-channel separation theorem states that in a communication system there is no performance loss if the source and channel code are designed independently. Actually, network protocols locate these codes in different layers. Furthermore, in communication systems with no retransmission capability, typically a complete channel decoder is used. However, in a system with progressive transmission, the use of an incomplete decoding can suppress errors in segments related to successive refinements. This work proposes a scheme that replaces the use of a single complete decoding strategy by a combination which uses different channel decoding strategies, one for each distinct segments of the compressed signal. The proposed scheme uses a fixed encoder, at the transmitter, but the many combinations of incomplete decoding modes, restricted to the receiver premisses, leads to system performances which surpasses that of a system with complete decoding only. Preliminary results revealed that the use of this novel scheme brings promising improvements. For a simple communication system, improvements on the order of 0.2 dB in bit energy were observed.

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