Receiver based Rate Adaptation Approach through Blind SNR Estimation of Satellite Channel

A joint source and channel coding approach for image transmission over a satellite based broadcast channel is proposed. A resolution scalable source is matched to a hierarchical constellation in order to achieve an adaptive decoding capability. An estimate of signal to noise ratio (SNR) is derived blindly at the receiver and is used to facilitate reception at lower information rate. The rate is reduced by switching to a lower level constellation from hierarchical QAM. This ensures graceful degradation in performance and guarantees service with lower resolution for channel under-going high AWGN noise. The simulation results suggest that, for very noisy channels, the end to end distortion so obtained is much lesser compared to decoding at full resolution.