Digital-to-analog video transmission method based on superposition modulation coding

Abstract

The invention relates to a digital-to-analog video transmission method based on superposition modulation coding. The method includes a video code sending process and a video receiving reconstruction process, and the video code sending process includes the following steps: an original video signal is subjected to hierarchical coding of base layer digital coding and enhancement layer analog coding, thereby correspondingly obtaining a digital channel coded signal and an analog coded signal, and the digital channel coded signal and the analog coded signal are superposed according to optimal allocation power based on a power constraint model and then sent. Compared with the prior art, the digital-to-analog video transmission method based on the superposition modulation coding makes full use of a power headroom in digital coded modulation to transmit information related with the enhancement layer, and reconstruction quality of video transmission is enhanced while the power utilization rate is improved.

Description

Technical field [0001] The present invention relates to the field of wireless communication, in particular to a digital-analog hybrid video transmission method based on superposition modulation coding. Background technique [0002] Nowadays, with the popularity of wireless networks and wireless devices, wireless video services are getting hotter. The use of image and video data in wireless networks is accelerating, so there is an urgent need to study new wireless transmission methods for image and video. As an effective transmission method to overcome the cliff effect, digital-analog hybrid transmission has also begun to be widely studied. The difference between video and traditional network data transmission is that video has higher requirements for real-time performance. On the other hand, users can tolerate some errors and distortions in video transmission. This creates an application scenario for analog coding transmission. There are several problems in the field of wirele...

AI Technical Summary

Problems solved by technology

There are several problems in the field of wireless video research: First, mobility. For example, the location of a user holding a mobile device is constantly changing, so its channel is also changing, so the quality of the channel is also constantly changing. Second, for wireless video broadcast transmission, different users are in different locations, and the channel also has diversity characteristics; third, with the popularization of video applications, the time resolution and spatial resolution of the receiving end from mobile phones to personal computers different resolutions

However, this optimal performance has a premise. First, the channel quality must be estimated very accurately; once the code rate of the source digital code is determined, if the channel quality changes, the channel will become better, and the improved channel quality cannot be used. If the channel quality becomes worse and reaches a critical point, the entire video quality will have a cliff effect.

Therefore, in digital video transmission, although the digital coding efficiency is high, its coding performance is high in the case of estimating the quasi-channel state, but it lacks scalability

[0004] The core problem of the cliff effect is that in digital coding, when mapping source symbols to channel symbols, it is not a linear mapping

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