Optimization of Error Concealment based on analysis of Fading Types. Part 2: Modified and New Models of Video Signal Error Concealment. Practical Simulations and their Results
Abstract
Purpose: This work is based on the recent research investigations in the combination of two subjects: Fading and Error Concealment. The main aim of the work is to present a more effective method of calculations of fading channel's parameters and to devise methods of achieving of better and more effective performance of Error Concealment, which will lead to higher quality of the video signals after passing through the fading channel. Methods: We explore the influence of fading on a communication channel, by studying the Gaussian, Gaussian, and Ricean distributions. Additionally, we explore existing methods of prediction and of Error Concealment and their influence on the video quality after its exit from the fading channel. Results: It is demonstrated that the Ricean distribution is broader and that it includes the other distributions, Gaussian (ideal channel) and Rayleigh (channel with a strong fading). Therefore, this distribution is used for tests of practical cases occurring in the video channel. On the issue of Error Concealment, a method of Symmetrical CALIC which is an optimization of the CALIC method, was implemented and compared with the original CALIC and with other methods. It has been determined that the proposed optimization yields better results than all the methods used for comparison. In addition, a new method of Error Concealment, named Balanced Percentage Calculation, is proposed. In comparison, its results are two times better on average than the results of Symmetrical CALIC, and are much better than the results of other methods used. Two themes have been combined in such a way that fading influenced the appearance oferrors in the video. Those errors have been replaced by the proposed methods of Error Concealment. All practical tests and comparisons were performed using the MatLab. Practical relevance: The proposed method of calculations of fading channel's parameters allows to perform calculations for all types of channels. This method significantly facilitates work with channels in general and with necessary calculations for channels in particular. The suggested optimization of the existing method of Error Concealment and the new proposed method of Error Concealment allow to receive higher quality video after passing through the fading channel.
