Satellite images broadcast based on wireless softcast scheme

This paper proposes a novel coding and transmis-sion scheme for satellite image broadcasting to a large number of receivers. First, the proposed scheme employs a hybrid 3D trans-form; it first applies a 1D low-complexity Karhunen-Loève trans-form (KLT) that used a clustering approach as spectral decorre-lating transform, and then followed by 2D discrete cosine trans-form (DCT) to remove redundant information within a spatial band. Second, the transmission power is directly allocated to the data according to their distributions and magnitudes without forward error correction (FEC). Third, these data are trans-formed by Hadamard matrix and transmitted over a dense con-stellation. The proposed scheme supports approximately the best quality to multiple users with diverse channel conditions without FEC and modulation. Experiments on satellite images demon-strate that the proposed scheme improves the average image quality by 2.49dB, 3.52dB, and 4.20dB over LineCast, SoftCast-3D, and Softcast-2D, respectively, and it achieves up to 7.33dB gain over JPEG2000 with FEC.