Inter-layer turbo coded unequal error protection for multi-layer video transmission

In layered video streaming, the enhancement layers (ELs) must be discarded by the video decoder, when the base layer (BL) is corrupted or lost due to channel impairments. This implies that the transmit power assigned to the ELs is wasted, when the BL is corrupted. To combat this effect, in this treatise we investigate the inter-layer turbo (IL-turbo) code, where the systematic bits of the BL are implanted into the systematic bits of the ELs at the transmitter. At the receiver, when the BL cannot be successfully decoded, the information of the ELs may be utilized by the IL-turbo decoder for the sake of assisting in decoding the BL. Moreover, for providing further insights into the IL technique the benefits of the IL-turbo scheme are analyzed using extrinsic information transfer (EXIT) charts in the scenario of unequal error protection (UEP) coded layered video transmission. Finally, our data partitioning based experiments show that the proposed scheme outperforms the traditional turbo code based UEP scheme by about an Eb/N0 of 1.1 dB at a peak signal-to-noise ratio (PSNR) of 36 dB or 3 dB of PSNR at an Eb/N0 of -5.5 dB at the cost of a complexity increase of 13%

Iterative source and channel decoding relying on correlation modelling for wireless video transmission

Since joint source-channel decoding (JSCD) is capable of exploiting the residual redundancy in the source signals for improving the attainable error resilience, it has attracted substantial attention. Motivated by the principle of exploiting the source redundancy at the receiver, in this treatise we study the application of iterative source channel decoding (ISCD) aided video communications, where the video signal is modelled by a first-order Markov process. Firstly, we derive reduced-complexity formulas for the first-order Markov modelling (FOMM) aided source decoding. Then we propose a bit-based iterative horizontal vertical scanline model (IHVSM) aided source decoding algorithm, where a horizontal and a vertical source decoder are employed for exchanging their extrinsic information using the iterative decoding philosophy. The iterative IHVSM aided decoder is then employed in a forward error correction (FEC) encoded uncompressed video transmission scenario, where the IHVSM and the FEC decoder exchange softbit-information for performing turbo-like ISCD for the sake of improving the reconstructed video quality. Finally, we benchmark the attainable system performance against a near-lossless H.264/AVC video communication system and the existing FOMM based softbit source decoding scheme, where The financial support of the RC-UK under the auspices of the India-UK Advanced Technology Centre (IU-ATC) and that of the EU under the CONCERTO project as well as that of the European Research Council’s Advanced Fellow Grant is gratefully acknowledged. The softbit decoding is performed by a one-dimensional Markov model aided decoder. Our simulation results show that Eb=N0 improvements in excess of 2.8 dB are attainable by the proposed technique in uncompressed video applications

Iterative two-dimensional error concealment for low-complexity wireless video uplink transmitters

Since joint source-channel decoding is capable of exploiting the residual redundancy in the encoded source signals for improving the attainable error resilience, it has attracted substantial attention. Motivated by the principle of exploiting the source redundancy at the receiver, in this treatise we study the application of iterative Error Concealment (EC) for low-complexity uplink video communications, where the video signal is modelled by a first-order Markov process. Firstly, we derive reduced-complexity formulas for the first-order Markov modelling aided source decoding. Then we propose a bit-based iterative EC algorithm, where a horizontal and a vertical source decoder are employed for exchanging their information using the iterative decoding philosophy. This scheme may be combined with low-complexity video codecs, provided that they retain some of the redundancy residing in the video signals and are capable of estimating the softbit information representing each bit of the video pixels. As application examples, we test our proposed two-dimensional iterative EC in both Wyner-Ziv video coded and uncompressed video transmission scenarios. Finally, we benchmark the attainable system performance against the existing first-order Markov process based softbit source decoding scheme, where the softbit decoding is performed by a one-dimensional Markov model aided decoder, as well as by the existing pixel-domain Wyner-Ziv video scheme. Our simulation results show that Eb/N0 improvements in excess of 6 dB are attainable by the proposed technique in uncompressed video home-networking applications. Furthermore, up to 21.5% bitrate reduction is achieved by employing our proposed iterative error concealment technique in a Wyner-Ziv video coding scheme

Historical information aware unequal error protection of scalable HEVC/H.265 streaming over free space optical channels

Free space optical (FSO) systems are capable of supporting high data rates between fixed points in the context of flawless video communications. Layered video coding facilitates the creation of different-resolution subset layers for variablethroughput transmission scenarios. In this paper, we propose Historical information Aware Unequal Error Protection (HAUEP) for the scalable high efficiency video codec (SHVC) used for streaming over FSO channels. Specifically, the objective function (OF) of the current video frame is designed based on historical information of its dependent frames. By optimizing this OF, specific subset layers may be selected in conjunction with carefully selected forward error correction (FEC) coding rates, where the expected video distortion is minimized and the required bitrate is reduced under the constraint of a specific throughput. Our simulation results show that the proposed system outperforms the traditional equal error protection (EEP) scheme by about 4.5 dB of Eb=N0 at a peak signal-to-noise ratio (PSNR) of 33 dB. From a throughput-oriented perspective, HA-UEP is capable of reducing the throughput to about 30% compared to that of the EEP benchmarker, while achieving an Eb=N0 gain of 4.5 dB

Wireless holographic image communications relying on unequal error protected bitplanes

Holography is considered to be one of the most promising techniques of goggle-free visualization of the nearfuture. We consider wireless transmission of digital holograms, which are partitioned into multiple bitplanes that are then independently encoded by a forward error correction (FEC) code for transmission over wireless channels. The coding rates of these bitplanes will be optimized at the transmitter for the sake of achieving an improved holographic peak signal-to-noise ratio (PSNR) at the receiver. Our simulation results show that up to 2.6 dB of Eb=N0 or 12.5 dB of PSNR improvements may be achieved, when employing a recursive systematic convolutional (RSC) code

Wireless Video: An Interlayer Error-Protection-Aided Multilayer Approach

Video clips captured from realworld scenes exhibit intraframe correlation among their pixels. This correlation can be removed by applying video compression to reduce the required the storage space, transmission bandwidth, bitrate, and power. Layered video coding separates the video sequence into partitions having unequal importance, hence allowing the decoder to progressively refine the reconstructed video quality, when an increased bandwidth is available. On the other hand, compressed video signals are sensitive to channel errors. Therefore, forward error correction (FEC) must be applied when communicating over hostile wireless channels. In addition, based on the fact that the different layers have unequal importance, different-rate FEC codes may be applied to the different layers, leading to unequal error protection (UEP). We propose an interlayer (IL) FEC coding technique combined with UEP, where the lower-importance layers are used for protecting the higher-importance layers in the data-partitioned mode of H.264/advanced video coding (AVC). Explicitly, our simulation results show that the IL coded system outperforms the traditional UEP system by providing a better video quality for transmission over a wireless channel having Eb /N0 of 0 dB, when using our multifunctional multiple-input, multiple-output (MIMO) array