Video transmission over wireless networks

Compressed video bitstream transmissions over wireless networks are addressed in this work. We first consider error control and power allocation for transmitting wireless video over CDMA networks in conjunction with multiuser detection. We map a layered video bitstream to several CDMA fading channels and inject multiple source/parity layers into each of these channels at the transmitter. We formulate a combined optimization problem and give the optimal joint rate and power allocation for each of linear minimum mean-square error (MMSE) multiuser detector in the uplink and two types of blind linear MMSE detectors, i.e., the direct-matrix-inversion (DMI) blind detector and the subspace blind detector, in the downlink. We then present a multiple-channel video transmission scheme in wireless CDMA networks over multipath fading channels. For a given budget on the available bandwidth and total transmit power, the transmitter determines the optimal power allocations and the optimal transmission rates among multiple CDMA channels, as well as the optimal product channel code rate allocation. We also make use of results on the large-system CDMA performance for various multiuser receivers in multipath fading channels. We employ a fast joint source-channel coding algorithm to obtain the optimal product channel code structure. Finally, we propose an end-to-end architecture for multi-layer progressive video delivery over space-time differentially coded orthogonal frequency division multiplexing (STDC-OFDM) systems. We propose to use progressive joint source-channel coding to generate operational transmission distortion-power-rate (TD-PR) surfaces. By extending the rate-distortion function in source coding to the TD-PR surface in joint source-channel coding, our work can use the ??equal slope?? argument to effectively solve the transmission rate allocation problem as well as the transmission power allocation problem for multi-layer video transmission. It is demonstrated through simulations that as the wireless channel conditions change, these proposed schemes can scale the video streams and transport the scaled video streams to receivers with a smooth change of perceptual quality

Scalable H.264 Wireless Video Transmission over MIMO-OFDM Channels

Abstract. A cross-layer optimization scheme is proposed for scalable video transmission over wireless Multiple Input Multiple Output Orthogonal Frequency Division Multiplexing (MIMO-OFDM) systems. The scalable video coding (SVC) extension of H.264/AVC is used for video source coding. The proposed cross-layer optimization scheme jointly optimizes application layer parameters and physical layer parameters. The objective is to minimize the expected video distortion at the receiver. Two methods have been developed for the estimation of video distortion at the receiver, which is essential for the cross-layer optimization. In addition, two different priority mappings of the SVC scalable layers are considered. Experimental results are provided and conclusions are drawn

A Study on the Usage of Cross-Layer Power Control and Forward Error Correction for Embedded Video Transmission over Wireless Links

Cross-layering is a design paradigm for overcoming the limitations deriving from the ISO/OSI layering principle, thus improving the performance of communications in specific scenarios, such as wireless multimedia communications. However, most available solutions are based on empirical considerations, and do not provide a theoretical background supporting such approaches. The paper aims at providing an analytical framework for the study of single-hop video delivery over a wireless link, enabling cross-layer interactions for performance optimization using power control and FEC and providing a useful tool to determine the potential gain deriving from the employment of such design paradigm. The analysis is performed using rate-distortion information of an embedded video bitstream jointly with a Lagrangian power minimization approach. Simulation results underline that cross-layering can provide relevant improvement in specific environments and that the proposed approach is able to capitalize on the advantage deriving from its deployment

Analyzing video compression for transporting over wireless fading channels

Wireless video communication is becoming increasingly popular these days with new applications such as TV on mobile and video phones. Commercial success of these applications requires superior video quality at the receiver. So it is imperative to analyze the effect of a wireless channel on a video transmission. The aim of this research is to analyze the video transmission over Rayleigh fading channels for various bit error rates (BER), signal to noise ratios (Eb/N0) and Doppler rates, and to suggest which source coding scheme is best at which BER, Eb/N0 and Doppler rates. Alternative schemes such as hybrid (digital/analog) schemes were considered and their performances were compared with pure digital communication. It is also shown that the combination of digital and analog video communication does not yield any better performance compared to pure digital video communication

Optimal cross layer design for CDMA-SFBC wireless systems

The demand for high speed reliable wireless services has been rapidly growing. Wireless networks have limited resources while wireless channels suffer from fading, interference and time variations. Furthermore, wireless applications have diverse end to end quality of service (QoS) requirements. The aforementioned challenges require the design of spectrally efficient transmission systems coupled with the collaboration of the different OSI layers i.e. cross layer design. To this end, we propose a code division multiple access (CDMA)-space frequency block coded (SFBC) systems for both uplink and downlink transmissions. The proposed systems exploit code, frequency and spatial diversities to improve reception. Furthermore, we derive closed form expressions for the average bit error rate of the proposed systems. In this thesis, we also propose a cross layer resource allocation algorithm for star CDMA-SFBC wireless networks. The proposed resource allocation algorithm assigns base transceiver stations (BTS), antenna arrays and frequency bands to users based on their locations such that their pair wise channel cross correlation is minimized while each user is assigned channels with maximum coherence time. The cooperation between the medium access control (MAC) and physical layers as applied by the optimized resource allocation algorithm improves the bit error rate of the users and the spectral efficiency of the network. A joint cross layer routing and resource allocation algorithm for multi radio CDMA-SFBC wireless mesh networks is also proposed in this thesis. The proposed cross layer algorithm assigns frequency bands to links to minimize the interference and channel estimation errors experienced by those links. Channel estimation errors are minimized by selecting channels with maximum coherence time. On top, the optimization algorithm routes network traffic such that the average end to end packet delay is minimized while avoiding links with high interference and short coherence time. The cooperation between physical, MAC and network layers as applied by the optimization algorithm provides noticeable improvements in average end to end packet delay and success rat

Development of resource allocation strategies based on cognitive radio

[no abstract

Video traffic : characterization, modelling and transmission

EThOS - Electronic Theses Online ServiceGBUnited Kingdo