Jie Liang

Simon Fraser University · School of Engineering Science

Intelligent reflecting surface (IRS) has emerged as a potential technology to achieve smart wireless communications and high energy efficiency. On the other hand, nonorthogonal multiple access (NOMA)-enabled backscatter communications have shown a great potential in large-scale Internet of Things (IoT) networks. In this article, we consider a downl...

In this paper, we investigate the performance of a non-orthogonal multiple access (NOMA) wireless system, in which signal transmission of a far user is assisted by a near user. In particular, we examine the outage performance of the underlying scenario with two cooperative forwarding protocols incorporated, namely, the hybrid decode-amplify-forward...

The hybrid digital-analog (HDA) video transmission scheme can be used to avoid the cliff effect and saturation effect. However, directly using HDA in 3D video transmission requires too much bandwidth. This paper addresses synthesis-distortion-aware HDA transmission for 3D videos to improve transmission performance. First, a 3D HDA framework that tr...

In recent years, with the development of Internet communication technology, more and more people tend to get information through the network. And people prefer multimedia video streaming services. Traditional streaming media technology cannot meet people’s needs because of its limitations. Recently, HTTP-based Dynamic Adaptive Streaming Over HTTP (...

Non-orthogonal multiple access (NOMA) was recently regarded as a potential technique for next generation wireless networks. Recent works on relay selection for cooperative NOMA systems have mainly addressed the best relay selection to forward its received signals to terminal nodes. Nonetheless, in practical scenarios, the best relay may be unavaila...

With the tremendous growth of video contents and mobility demands, there is a need to develop more personalized video services. Split-screen services, such as picture in picture become more and more popular. Furthermore, the user’s viewing environment affects the user’s quality of experience (QoE). Therefore, video transmission of split-screen serv...

Non-orthogonal multiple access (NOMA) has been proposed as a promising technology that is capable of improving the spectral efficiency of fifth-generation wireless networks and beyond. However, in practical communication scenarios, transceiver architectures inevitably suffer from radio frequency (RF) front-end related impairments that cause non-neg...

The precise error performance analysis is challenging for non-orthogonal multiple access (NOMA) systems due to nonlinear successive interference cancellation (SIC) processing among NOMA users. In this paper, the pairwise error probability (PEP) performance of different users is investigated for relay NOMA simultaneous wireless information and power...

The purpose of wireless video multicast is to send a video signal simultaneously to multiple heterogeneous users, each of whom desires video quality that matches its channel condition. The current compressed sensing (CS)-based wireless video multicast has some advantages but also some shortcomings, such as high computational and low reconstruction...

In this paper, color-depth conditional generative adversarial networks (CDcGAN) are proposed to resolve the problems of simultaneous color image super-resolution and depth image super-resolution in 3D videos. Firstly, a generative network is presented to leverage the mutual information of the low-resolution color image and low-resolution depth imag...

In this paper, a local activity measurement of the clipped and normalized variance or standard deviation is proposed to drive anisotropic diffusion and relative total variation (RTV) to work better for structural preservation. Firstly, two novel edge-stop functions are introduced for our local activity-driven anisotropic diffusion (LAD-AD) to effic...

In this paper, we report our study of SoftCast-based soft video transmission with multiple antennas, which provides high spectrum efficiency and a high transmission rate and overcomes the cliff effect of the digital scheme. However, current soft video transmission with multiple antennas cannot achieve better video performance because it uses only a...

Hybrid digital-analog (HDA) video transmission scheme has shown advantages in avoiding the cliff effect. However, most current HDA schemes assume perfect transmission of the digital signal, which is hardly the case in practice. In this paper, we propose an adaptive recursive distortion estimate for HDA system (ARDE-HDA), which recursively estimates...

During 3-D video communication, transmission errors such as packet loss could happen to the texture and depth sequences. View synthesis distortion will be generated when these sequences are used to synthesize virtual views according to the depth-image-based rendering method. Depth-value-based graphical model (DVGM) has been employed to achieve the...

In 3D video coding and depth-based image rendering, the distortion of the compressed depth image often leads to wrong 3D warpping. In this paper, by generalizing the recent work of convolutional neural network (CNN)-based depth image up-sampling, we propose a CNN-based depth image artifact removal scheme, where both the compressed depth and color i...

In interactive multiview video streaming (IMVS), the viewers can periodically switch viewpoints. If the captured view is not available at the desired viewpoint, virtual views can be rendered from neighboring coded views using view synthesis techniques. Dynamic adaptive streaming over HTTP (DASH) is a new standard that allows to adjust the quality o...

Learning-based image super-resolution methods often use large datasets to learn texture features. When these methods are applied to depth images, emphasis should be given on learning the geometrical structures at object boundaries, since depth images do not have much texture information. In this paper, we develop a scheme to learn multiple residual...

The resolution of the depth map captured by a time-of-flight camera is rather limited; hence, it cannot be directly used to build a high-quality 3D model, together with an associated high-resolution texture image. In this paper, an improved depth up-sampling algorithm that considers two important characteristics of the depth map is proposed. First,...

Deep neural networks generally involve some layers with mil- lions of parameters, making them difficult to be deployed and updated on devices with limited resources such as mobile phones and other smart embedded systems. In this paper, we propose a scalable representation of the network parameters, so that different applications can select the most...

We consider a single-input-multiple-output (SIMO) system over generalized and composite fading channels using the mixture Gamma (MG) distribution in the presence of impulsive noise, which is modeled by the Middleton's Class-A (MCA) and -mixture noise models. First, we develop a simple and effective information-theoretic approach to determine the op...

In free viewpoint video systems, a user has the freedom to select a virtual view from which an image of the 3D scene is rendered, and the scene is commonly represented by color and depth images of multiple nearby viewpoints. In such representation, there exists data redundancy across multiple dimensions: a 3D voxel may be represented by pixels in m...

Dictionary learning for sparse representation has drawn considerable attention in recent years. In particular, the K-SVD algorithm is an efficient approach, and various modifications of the K-SVD have been developed for applications such as face recognition. However, the efficient storage of the dictionary has not been studied. Currently, the dicti...

The present paper is devoted to the evaluation of energy detection based spectrum sensing over different multipath fading and shadowing conditions. This is realized by means of a unified and versatile approach that is based on the particularly flexible mixture gamma distribution. To this end, novel analytic expressions are firstly derived for the p...

We consider multi-resolution (MR) compressed sensing reconstruction , where instead of always reconstructing the signal at the original high resolution (HR), we enable the reconstruction of a better-quality low-resolution (LR) signal when the sampling rate is too low. We propose an approximate message passing (AMP)-based solution (MR-AMP). Theoreti...

IEEE Trans. on Computational Imaging, submitted, Jul. 2015.

In this paper, we consider the problem of multi-resolution compressed sensing (MR-CS) reconstruction, which has received little attention in the literature. Instead of always reconstructing the signal at the original high resolution (HR), we enable the reconstruction of a better-quality low-resolution (LR) signal when the number of available CS sam...

In this paper, we study the compressed sensing reconstruction problem with generalized elastic net prior (GENP), where a sparse signal is sampled via a noisy underdetermined linear observation system, and an additional initial estimation of the signal (the GENP) is available during the reconstruction. We first incorporate the GENP into the LASSO an...

The analysis of composite fading channels, which are typically encountered in wireless channels due to multipath and shadowing is quite involved, as the underlying fading distributions do not lend themselves to analysis. An example of such channels are the Nakagami/Rayleigh-Lognormal fading channels. Several simplified expressions have been propose...

Depth-image-based rendering (DIBR) is frequently used in multiview video applications such as free-viewpoint television. In this paper, we consider the two DIBR algorithms used in the Moving Picture Experts Group view synthesis reference software, and develop a scheme for the encoder to estimate the distortion of the synthesized virtual view at the...

Considerable efforts have been devoted to statistical modeling and the characterization of channels in a range of statistical models for fading channels. In this paper, we consider a unified approach to model wireless channels by the mixture of Gaussian (MoG) distribution. Simulations provided have shown the new probability density function to accu...

Recently, Dynamic Adaptive Streaming over HTTP (DASH) has attracted significant attention. In this paper, we consider DASH-based transmission of scalable videos in wireless broadband access networks (e.g., long-term evolution and WiMAX), and propose three methods to enhance the quality of experience of wireless DASH users. First, we design an impro...

We present a unified framework to evaluate the error rate performance of wireless networks over generalized fading channels. In particular, we propose a new approach to represent different fading distributions by mixture of Gamma distributions. The new approach relies on the expectation-maximization (EM) algorithm in conjunction with the so-called...

In this paper, we propose a real-time successively refinable image transmission framework over coded cooperative networks. An Unequal Error Protection (UEP) scheme is designed to jointly allocate bits among source coding, channel coding and cooperation to minimize the reconstructed distortion at the receiver. The proposed scheme has a low complexit...

Compression of dynamic 3D geometry obtained from depth sensors is challenging, because noise and temporal inconsistency inherent in acquisition of depth data means there is no one-to-one correspondence between sets of 3D points in consecutive time instants. In this paper, instead of coding 3D points (or meshes) directly, we propose to represent an...

In VANET (vehicular ad hoc network), RSUs (road side units) have limited coverage and high deployment cost, so they are deployed sparsely in urban area, which leads to blind zone (BZ) between adjacent RSUs, where vehicles cannot connect to Internet by RSUs. In this paper, we study how to use RSUs and vehicles to download big files cooperatively in...

In depth-image-based-rendering (DIBR), the quality of the synthesized virtual view depends on that of the depth maps in the reference views. In this paper, we develop a framework to estimate the distortion of the synthesized view when a simplified two-step warping algorithm is used and when there are random errors in the reference depth maps. A gra...

In this paper, two multiple description coding schemes are developed, based on prediction-induced randomly offset quantizers and unequal-deadzone-induced near-uniformly offset quantizers, respectively. In both schemes, each description encodes one source subset with a small quantization stepsize, and other subsets are predictively coded with a larg...

In this paper, we study the side information-aided compressed sensing (SI-CS) reconstruction problem, where a sparse signal is measured via a noisy underdetermined linear observation system, and a side information is available during the reconstruction. We first formulate the optimization problem from the estimation theory point of view. The approx...

This paper proposes an improved source-splitting-based two-rate M-channel multiple description coding scheme, where the source is split into M subsets. In each description, one subset is coded at a high rate, and others are predictively coded at a low rate. Uniform offsets among low-rate quantizers of different descriptions are achieved by employin...

In this paper, a hybrid multiview imaging system is considered, where traditional cameras and compressed sensing (CS) cameras are interleavingly placed. To improve the reconstruction quality of the CS cameras, the interpolated image from the two neighboring traditional cameras is used as side information. Different from existing CS-based multiview...

In this paper, we study the performances of various layered source-channel coding schemes over two-way relay networks, where the sources are coded into different layers and transmitted by progressive coding or superposition coding. The two-way relay network employs multiple-access-broadcast or time- division-broadcast protocol, and the relay uses d...

Free viewpoint video enables a client to interactively choose a viewpoint from which to synthesize an image via depth-image-based rendering (DIBR). However, synthesizing a novel viewpoint image using texture and depth maps from two nearby views entails a sizable computation overhead. Further, to reduce transmission rate, recent proposals synthesize...

The just noticeable distortion (JND) map is a useful tool for perceptual video coding. However, direct calculation of the JND map incurs high complexity, and the problem is aggravated in multiview video coding. In this paper, two fast methods are proposed to generate the JND maps of multiview videos. In the first method, the JND maps of some anchor...

In this study, the authors investigate the outage probability of underlay cognitive radio systems with relay selection. In particular, they consider a secondary multi-relay network operating in the amplify-and-forward (AF) mode and only the `best' relay is selected, which satisfies an index of merit. The proposed selection strategy takes into consi...

This paper presents the design and implementation of an error-resilient H.264/AVC-based embedded video conferencing scheme over Internet. We first develop a fast recursive algorithm to estimate the decoder-side distortion of each frame in the presence of packet loss. The algorithm operates at block level, and considers the impacts of different intr...

We identify some challenges in RSU access problem. There are two main problems in V2R communication. (1) It is difficult to maintain the end-to-end connection between vehicles and RSU due to the high mobility of vehicles. (2) The limited RSU bandwidth resources lead to the vehicles’ disorderly competition behavior, which will give rise to multiple...

In this paper we propose a new noncoherent relay selection strategy for two-way relay cooperative networks. In our proposed scenario, channel state information (CSI) or feedback link is not needed, neither for relay selection nor for data detection. We assume Mary frequency shift keying (FSK) modulation for our transmission scheme and decode-and-fo...

The authors study the performance of wireless bidirectional relay-assisted networks in the presence of imperfect channel state information, where two end-source terminals S1 and S2 communicate with the assistance of M relay terminals Rj's. The max'min relay selection criterion is used to select the best relay that maximises the minimum signal-to-no...

Interactive multiview video streaming (IMVS) is an application where a network client requests from server a single video view at a time but can periodically switch to other views as the video is played back uninterrupted. Existing IMVS algorithms output pre-computed frame structures that facilitate permissible view-switching while minimizing the e...

This paper presents the design of Ztitch, a mobile phone application that can create immersive panoramic scenes in real time, where multiple photos are arranged in the 3D space according to their camera poses, maintaining a realistic perspective of the scene. By taking full advantage of the touchscreen, accelerometer, and gyroscope in the phone, Zt...

This paper presents a macroblock-level algorithm to estimate the end-to-end distortion of H.264/AVC-based video transmission that allows unrestricted intra prediction. Some fast approximations are developed to reduce its complexity so that it can be used in real-time applications. Experimental results demonstrate the performance of the algorithm an...

The just noticeable distortion (JND) map is a useful tool for perceptual video coding. However, direct calculation of the JND map incurs high complexity, and the problem is aggravated in multiview video coding. In this paper, the motion and disparity vectors obtained during the video coding are employed to predict the JND maps in order to reduce th...

This paper presents the theoretical analysis and simulation of noncausal directional intra prediction for image and video coding, where noncausal pixels, that is, pixels inside, below, or to the right of the target block, are used to predict the block, at the cost of extra bits to code those noncausal reference pixels. The proposed method generaliz...

In interactive multiview video streaming (IMVS), a client receives and observes one of many available viewpoints of the same scene and periodically requests from the server view switches to neighboring views, as the video is played back in time uninterruptedly. One key technical challenge is to design a frame coding structure that facilitates perio...

In this paper, we investigate the performance of relay selection in an underlay cognitive radio system in the presence of primary user (PU) interference. In particular, we consider a secondary multi-relay network operating in the amplify-and-forward (AF) mode and only the “best” relay which satisfies an index of merit is selected. The proposed sele...

In this paper, we investigate the performance of selection cooperation in the presence of imperfect channel estimation. In particular, we consider a cooperative scenario with multiple relays and amplify-and-forward protocol over frequency flat fading channels. In the selection scheme, only the "best" relay which maximizes the effective signal-to-no...

We study the performance of bidirectional multi-relay cooperative networks in the presence of imperfect channel state information by means of the correlation coefficient of the estimated channel gains and their actual values, where the max-min relay selection is used. We show that the performance is determined by the average performance of the two...

In this paper, we analyze the effect of feedback delay and channel estimation errors on the performance of a decode-and-forward (DF) cooperative transmission scenario with relay selection. In our relay selection scheme, only one relay with the best relay-to-destination (R → D) channel quality is selected among the set of relays that decode the sour...

Distortion exponent (DE) is the asymptotic exponential decay rate of the expected distortion between a source and its reconstruction in the high- SNR regime. This paper presents two improvements to the existing DE analyses of two-way relaying networks, where two users communicate in both directions with the help of a relay. First, we allow the user...

Modern smartphones provide an excellent platform for creating 3D scenes from photos. While there already exists many mobile applications that can stitch a set of photos to create a single, panoramic landscape photo, this paper proposes the creation of panoramic scenes where multiple photos are projected in a 3D space using the pinhole camera model,...

The authors investigate the effect of feedback delay on the average capacity of a decode-and-forward cooperative network with relay selection. In particular, a multi-relay cooperative scenario is considered, where the best relay is selected from a subset of relays that are able to decode the source information correctly. In this selection scenario,...

A three-layer scheme is developed for M-channel multiple description image coding. In each description, a subset of the source is encoded in the first layer. In the second layer, the remaining subsets are encoded sequentially by predicting from the already encoded subsets. Each description can thus produce a coarse reconstruction of the source. Whe...

In this paper, we study the transmission of Gaussian signals in a three-node two-way relay network, where two users communicate in both directions at possibly different rates, with the help of one relay. All nodes are half-duplex and equipped with single antenna. The relay employs the amplify-and-forward (AF) or decode-and-forward (DF) based cooper...

JPEG XR is the latest image compression standard. In this paper, two graph-based soft decision quantization (SDQ) methods are developed to optimize the rate-distortion performance of JPEG XR. The first approach uses a full graph, whose number of states is determined by the block size. The second method employs a fast and adaptive event-based graph,...

Interactive multiview video streaming (IMVS) is an application that streams to a client one out of N available video views for observation, but client can periodically request switches to neighboring views as the video is played back uninterrupted in time. Previous IMVS works focused on the design of a frame structure at encoding time, trading off...

Traditional multiview video coding schemes compress all captured video frames exploiting all possible inter-view and temporal frame correlation for coding gain, creating complex inter-frame dependencies in the process. In contrast, interactive multiview video streaming (IMVS) demands data navigation flexibility in the frame structure design, so tha...

In this paper, we first develop improved projective rectification-based view interpolation and extrapolation methods, and apply them to view synthesis prediction-based multiview video coding (MVC). A geometric model for these view synthesis methods is then developed. We also propose an improved model to study the rate-distortion (R-D) performances...

A fair P2P scalable video streaming scheme is proposed in this paper. The contributions of the paper are threefold. First, to improve the quality fairness of multiple video streams, a modified Lloyd-Max quantization-based Priority Index (PID) assignment method for scalable video coding (SVC) is developed, where the base-layer quality is also embedd...

In this paper, a perceptual multiview video coding scheme is proposed, based on the synthesized Just Noticeable Distortion (JND) maps. In JND-based perceptual video coding, the residues after intra or inter prediction are tuned according to the corresponding JND thresholds to save the bits without affecting the perceptual quality. In our scheme, to...

In this paper, we study the end-to-end distortions when transmitting two Gaussian signals in a three-node, half-duplex, and two-way relaying network, where two users communicate in both directions with the help of one relay, and can transmit at different rates. We focus on the two-phase Multiple-Access Broadcast (MABC) cooperation protocol with dec...

In this letter, we investigate cooperative diversity with relay selection over cascaded Rayleigh fading channels. In particular, we analyze the performance of a relay selection scheme for cooperative vehicular networks with the decode-and-forward (DF) protocol. Only the “best” relay, which satisfies an index of merit, is selected. We ignore the dir...

In this letter, we investigate the effect of feedback delay and channel estimation errors in a decode-and-forward (DF) cooperative network with relay selection. In particular, we consider a multirelay cooperative scenario, where the best relay is selected from a subset of relays that are able to decode the source information correctly. In the selec...

In this paper, we investigate the performance of selection cooperation in the presence of imperfect channel estimation. In particular, we consider a cooperative scenario with multiple relays and amplify-and-forward protocol over frequency flat fading channels. In the selection scheme, only the "best" relay which maximizes the effective signal-to-no...

In this paper, we investigate the performance of selection cooperation in the presence of imperfect channel estimation. In particular, we consider a cooperative scenario with multiple relays and amplify-and-forward protocol over frequency flat fading channels. In the selection scheme, only the "best" relay which maximizes the effective signal-to-no...

In this paper, we investigate the performance of selection cooperation in the presence of imperfect channel estimation. In particular, we consider a cooperative scenario with multiple relays and amplify-and- forward protocol over frequency flat fading channels. In the selection scheme, only the "best" relay which maximizes the effective signal-to-n...

A rate control algorithm is introduced to the JPEG XR still image compression algorithm, thereby allowing the user to compress an image to a target bit-rate. Using ρ-domain analysis, we showed a strong linearity relationship of the rate function R(ρ). This allows us to accurately estimate the rate-distortion function, and thus control bit-rate of t...

Multiview image acquisition systems usually involve many closely-located cameras. In some scenarios, it might be possible to significantly reduce the sample rates of some cameras and still reconstruct the corresponding images with good quality, by taking advantage of the side information from neighboring views. In this paper, we investigate the app...

In this paper, a three-layer scheme is developed for M-channel multiple description image coding. In each description, a subset of the source samples is encoded in the first layer. In the second layer, the remaining subsets are encoded sequentially by predicting from the already encoded subsets. The third layer encoding is designed to refine the re...

In this paper, we consider the transmission of a Gaussian source over a cooperative relay network, and analyze its end-to-end distortion at high signal-to-noise ratio, in terms of the distortion exponent. Our contributions are threefold. First, we extend the existing distortion exponent analyses to cooperative networks with an arbitrary number of r...

In this paper, we consider the transmission of a Gaussian source in a multi-relay cooperative network, where limited channel-state feedback is combined with separate source and channel coding to help the transmission. We analyze the end-to-end distortion of the system at a high signal-to-noise ratio (SNR) in terms of the distortion exponent. The ac...

An improved rate-distortion model is developed to compare the performances of different multiview video coding (MVC) schemes. We first formulate the coding efficiency of one frame with a given temporal and inter-view prediction configuration. The overall performance of a MVC scheme is then obtained by averaging the coding efficiencies of all frames...

A low complexity M -channel multiple description coding scheme is developed in this paper, in which each description carries one subset of the input with a higher bit rate and the rest with a lower bit rate. The lower-rate codings in different descriptions are designed to be mutually refinable using staggered scalar quantizers. For correlated sourc...

In this paper, we study the transmission of Gaussian signals in a three-node half-duplex bidirectional relaying network, where two users communicate in both directions with the help of one relay, and can transmit at different rates. The relay employs amplify-and-forward (AF) or decode-and-forward (DF) based cooperation protocols. We analyze the dis...

In this paper, an improved algorithm to generate a smooth and accurate depth map for view synthesis and multiview video coding is developed. For each block in the target view, the algorithm first uses epipolar geometry to find its matched block in the reference view, from which an initial depth is obtained using the triangulation method and depth p...

In this paper, we investigate the performance of selection cooperation in the presence of channel estimation errors. In particular, we consider a cooperative scenario with multiple relays and amplify-and-forward protocol over frequency flat fading channels. In the selection scheme, only the "best" relay which maximizes the effective signal-to-noise...

In this paper, we investigate the performance of selection cooperation in the presence of channel estimation errors. In particular, we consider a cooperative scenario with multiple relays and amplify-and-forward protocol over frequency flat fading channels. In the selection scheme, only the “best” relay which maximizes the effective signal-to-noise...

In this paper, we analyze the impact of imperfect channel estimation on the performance of pilot symbol assisted modulation (PSAM) used in a relay communication system with distributed space time block code (STBC) and amplify-and-forward protocol. We derive correlation coefficients between the channel coefficients and their estimates when the relay...

Wireless networks are experiencing a paradigm shift from focusing on the traditional data transfer to accommodating the rapidly increasing multimedia traffic. Hence, their scheduling algorithms have to concern not only network-oriented quality-of-service (QoS) profiles, but also application-oriented QoS targets. This is particularly challenging for...

A fast priority index (PID) assignment algorithm is developed for the MGS (Medium Grain Scalability) packets in the scalable extension of the H.264/AVC. The contributions of the paper are threefold. First, we formulate the index assignment problem as the quantization of the rate-distortion (R-D) slopes of MGS packets, and use the Lloyd-Max algorith...