# Resource Optimization for 3D Video SoftCast with Joint Texture/Depth Power Allocation
## 5 Simulation Results
### Minimum Distortion Optimization Performance  
We investigated the highest PSNR attained given the available resource (i.e., power and bandwidth). As discussed earlier, we let the maximum number of available channel slots \(N\) for one GOP be 8192, where each channel slot transmits only one chunk. As assumed, each GOP transmits a separate texture and depth map for each reference view. Thus the available channel slots \(N\) for each GOP are split equally \(N_{sub}=\frac{N}{2\times\text{No.reference views}}\), and \(N_{sub}\) becomes the number of available channel slots for each texture and depth map. Furthermore, the noise variance was fixed at 1, and the transmission power budget \(P\) was varied for each GOP (Since the noise level is assumed to be fixed, then in the following we no longer differentiate between \(P\) and \(SNR_{clk}\)). Figure 2 shows the minimum distortion optimization results for the _Kendo_ and _PoznanStreet_ sequences. Note that the average results for the two transmitted reference views were used. As shown, for a given bandwidth resource usage \(N_{sub}\), the quality commonly increased with the power budget \(SNR_{clk}\), as was also proved in (12). Nevertheless, for a given power budget \(SNR_{clk}\), the quality did not necessarily increase with the bandwidth usage, mainly under low power budgets. For instance, in the texture frames, when the transmission power \(P\) was 5 dB, the PSNR\({}_{max}\) points for _Kendo_ and _PoznanStreet_ were achieved when \(N_{sub}=233\) and \(N_{sub}=303\), respectively. Achieving the highest PSNR did not always correspond to the maximum bandwidth usage because, in a pseudo-analog system, different chunks are not equally important, even though each chunk consumes one channel. Hence, more power allocation to HP chunks and less to LP chunks can improve PSNR performance under a limited power budget. Figure 2: Minimum distortion optimization performance and PAR influence: (**a**) Kendo; (**b**) PoznanStreet. The minimum distortion optimization curves generally have a flat tail, which implies that above a certain PSNR level, increasing the power budget is more efficient than improving bandwidth use. For instance, for the texture frames in the _Kendo_ sequence, under power budget \(SNR_{chk}=10\) dB and bandwidth use \(N_{sub}=559\), the PSNR was 39 dB. The PSNR value did not improve if more bandwidth was assigned. On the other hand, a power increment from 10 dB to 15 dB resulted in a PSNR improvement of 4.3 dB, and a further increment from 10 dB to 20 dB resulted in a PSNR improvement of 7.8 dB. The previous calculations were all carried out under the consideration of an equal texture/depth power allocation ratio or PAR 1:1. The power allocation between the texture and depth map will be rearranged when performing minimum distortion optimization under the optimal PAR mentioned in Table 2. Figure 2 demonstrates the change in behavior after applying the optimal PAR. As more power is assigned to the reference viewpoints' texture, the received quality of the texture frames will be enhanced, and the bandwidth allocation will increase at the expense of the depth map. In many cases, the bandwidth decrease in the depth map is greater than the bandwidth increase in the texture. The overall 3D video quality between two points (1848, 2048) along the bandwidth is drawn to show the improvement in the proposed resource control scheme. The _Kendo_ sequence corresponding to the average performance is plotted in Figure 3 to illustrate the bandwidth usage saving. Both the reference viewpoints' quality, and the five viewpoints' (two reference plus three virtual) overall quality are considered. As a scheme similar to the proposed scheme, the pioneering uncoded video transmission system SoftCast was applied to transmit each reference viewpoint texture and depth map separately, but with equal power allocation between texture and depth map or PAR 1:1. As shown, the conventional SoftCast employs the entire bandwidth and power resources to obtain a good PSNR.