Wireless video multicast has become one of the key technologies in wireless applications. But the\nmain challenge of conventional wireless video multicast, i.e., the cliff effect, remains unsolved. To overcome\nthe cliff effect, a hybrid digital-analog (HDA) video transmission framework based on SoftCast, which transmits\nthe digital bitstream with the quantization residuals, is proposed. With an effective power allocation algorithm and\nappropriate parameter settings, the residual gains can be maximized; meanwhile, the digital bitstream can\nassure transmission of a basic video to the multicast receiver group. In the multiple-input multiple-output\n(MIMO) system, since nonuniform noise interference on different antennas can be regarded as the cliff effect\nproblem, ParCast, which is a variation of SoftCast, is also applied to video transmission to solve it. The HDA\nscheme with corresponding power allocation algorithms is also applied to improve video performance.\nSimulations show that the proposed HDA scheme can overcome the cliff effect completely with the transmission\nof residuals. What is more, it outperforms the compared WSVC scheme by more than 2 dB when transmitting\nunder the same bandwidth, and it can further improve performance by nearly 8 dB in MIMO when compared with\nthe ParCast scheme. �© The Authors. Published by SPIE under a Creative Commons Attribution 3.0 Unported License. Distribution\nor reproduction of this work in whole or in part requires full attribution of the original publication, including its DOI. [DOI: 10.1117/1.JEI\n.25.1.013006]
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