# Resource Optimization for 3D Video SoftCast with Joint Texture/Depth Power Allocation
## 2 Related Work  
### SoftCast Video Transmission  
The energy efficiency of any network shows the extent to which the network can reduce distortion cost efficiently. In [13; 14], two examples of improving the network energy efficiency in two different networks are given. Video transmission over wireless network channels is challenging due to the time-varying channel characteristics and power constraints. In such systems, the objective of bit allocation between source and channel is to minimize the power consumption while maintaining satisfactory video quality, and this is also defined as the energy efficiency of the network. The SoftCast transmission scheme is an end-to-end architecture for wireless video transmission that replaces the complicated bit allocation in digital video transmission with a power allocation method. It differs from digital video transmission in the video encoding mechanism, assuring error resilience and transmission. Unlike conventional digital video transmission, the SoftCast approach depends on analog code to achieve linearity and a compression-protection trade-off with an optimal power allocation. In addition to the excellent video quality reception, which is linearly dependent on the channel condition, SoftCast offers scalability that is realized by broadcasting only a single signal. To improve the SoftCast efficiency, [PERSON] et al. [15] first replaced 3D-DCT with motion-compensated temporal filtering (MCTF) and then proposed DCast [16], a distributed source coding that exploits the inter-frame redundancy. In [17; 18], adaptive chunk division was incorporated to achieve optimal transmission power usage, and in [19], the bandwidth and computation requirement were reduced. Some other studies suggested a hybrid digital-analog framework, incorporating analog transmission alongside digital transmission to take advantage of both systems, achieving a balance between robust adaptation capability and high coding efficiency [15; 20; 21; 22; 23; 24]. These systems can be categorized based on the type of information to be digitized and how the analog and  
Figure 1: Diagram of the proposed 3D video SoftCast. digital parts share the channel. With the increase in the wireless traffic burden on wireless networks, efficient network resource exploitation becomes necessary. Based on the Shannon capacity [6], the network capacity is enhanced via bandwidth increase and frequency reuse. In HDA-SIM [25], the bandwidth of digital traffic is treated as a hidden resource, where the analog modulated data are superimposed over existing digital traffic. [PERSON] et al. [26] proposed MCast, a linear video transmission system that retransmits data across multiple time slots and multiple channels to exploit the time and frequency resources. These authors also proposed MUCast [27] to solve the problem of resource allocation to realize efficient multi-user video transmission. To improve the network's energy efficiency in pseudo-analog 3D video transmission. [PERSON] et al. [28] suggested an uncoded wireless depth map transmission scheme using mean-removed block-based DCT to improve decorrelation and view-synthesis distortion, to enhance energy allocation efficiency. Power allocation scaling is performed on rearranged chunks that include inter-block DCT coefficients. [PERSON] et al. [29] considered the view-synthesis distortion in the power-distortion optimization problem to achieve optimal reconstruction quality in the reference and virtual views. The optimization problem was then solved in a closed form of texture/depth power allocation. In general, all the studies mentioned followed the minimum distortion optimization approach for a pseudo-analog system. Only a few studies addressed the target distortion. In [30], [PERSON] et al. proposed prediction models to solve the target distortion optimization problem for single-view video. The curve-fitting-based resource control algorithm allocates the constrained bandwidth and power resources to obtain the predefined quality. [PERSON] et al.