Performance analysis of H.264 encoder for high-definition video transmission over ultra-wideband communication link.

With the technological advancement, entertainment has become revolutionized and the High-definition (HD) video has become a common feature of our modern amusement devices. Moreover, the demand for wireless transmission of HD video is rising increasingly for its ubiquitous nature, easy installation and relocation. The high bandwidth requirement is the main concern for wireless transmission of high quality video streams. Research has been going on by the consumer electronics industry to provide different solutions of this issue, for the last few years. In this research work, HD video transmission feasibility using the Ultra-wideband (UWB) communication channel is analyzed. The UWB channel is selected for its short-range, high-speed data transmission capability at low-cost, and low-power consumption. The maximum transmitting range of this technology is about 10 m at 100 Mbps data rate. Simulation is conducted by controlling key parameters, such as, in-loop deblocking filter, group of pictures, and quantization parameter of an H.264/AVC encoder. Here, standard HD video streams with different motion characteristics are used, and the impact of these parameters change on the reconstructed video quality and the broadcasting data rate are analyzed. Finally, a generalized parameters settings, and a video content dependent settings for an H.264/AVC encoder are proposed for different bandwidth requirements, as well as acceptable video quality. Performance evaluation of these parameters settings is performed, and the results are quite satisfactory as long as the symbol energy to noise power density ratio, Es/No, is above 15. With the proposed parameters settings, maximum 20 Mbps data rate is achieved with 33.5 dB Y-PSNR

TechNews digests: Jan - Nov 2009

TechNews is a technology, news and analysis service aimed at anyone in the education sector keen to stay informed about technology developments, trends and issues. TechNews focuses on emerging technologies and other technology news. TechNews service : digests september 2004 till May 2010 Analysis pieces and News combined publish every 2 to 3 month

TechNews digests: Jan - Nov 2006

TechNews is a technology, news and analysis service aimed at anyone in the education sector keen to stay informed about technology developments, trends and issues. TechNews focuses on emerging technologies and other technology news. TechNews service : digests september 2004 till May 2010 Analysis pieces and News combined publish every 2 to 3 month

Ultra wideband gigabit powerline communication

PhDPowerline Communication (PLC) has long been established for low data rate applications by the electric supply companies. Since 1991, the European CENELEC standard EN 50065 has ruled the use of 3 - 148.5KHz frequency range for narrow band PLC applications. Sim- ilar standard has been established by the IEEE in the US, where a frequency range of 50 - 450KHz is available. The fast growth of Internet since the 1990s accelerated the demands for digital communication services. Furthermore, with the develop- ment of in-home networking, there is a need to establish high speed data links between multiple household devices. This makes PLC sys- tems march rapidly into the high frequency range above 1MHz. Exist- ing broadband PLC system in the 1.6 - 30MHz frequency range only provides data rates smaller than 200Mbps. With the growing demand of multimedia services such as High De nition (HD) video streaming, much faster transmission speed up to Gigabits per second is required and this can be achieved by increasing the operating frequencies. Ultra Wideband (UWB) transmission in free space provides extremely broad bandwidth for short-range, high data rate applications. If UWB signals could be transmitted over the powerline channels in the high frequency range above 30MHz, data rates up to gigabits per second could be achieved. In this thesis, the possibility of implementing ultra wideband trans- mission over the low voltage indoor powerline is investigated. The starting point is to understand the signal propagation characteristics over powerline cables, in the UWB frequency range. Experimental re- sults indicate that the signal degrades at an acceptable rate over the mains cable in a scaled down UWB frequency band (50MHz - 1GHz), which provides a potential operation band for UWB over PLC ap- plications. Key component for the PLC system, a broadband Radio Frequency (RF) coupler is designed and developed, to introduce UWB signals to the transmission channel. With the channel properties and coupling unit, extensive experimental investigations are carried out to analyse the powerline network environment, including channel loss, noise and radiated emission. Furthermore, theoretical channel capac- ity and link budget are derived from measured parameters. It is shown that the indoor powerline is a suitable media for data transmission in the high frequency range from 50 to 550MHz in the home environment. Finally, system level performance is analysed by modelling the Phys- ical Layer (PHY) data transmission. The Multiband-OFDM UWB proposal for IEEE 802.15.3a standard is used to predict the transmis- sion performance under di erent propagation paths and data rates. The research work conducted in this project has proven that UWB over PLC is highly feasible for future in-home applications. With the global promotion of smart grid applications, UWB over PLC will play an important role in providing high speed data transmission over the power networks

A high bit rate flexible MAC protocol for monitoring applications using 60ghz radio technology

In recent years there has been a growing trend in optical wireless convergence. One particular aspect of this is 60 GHz radio-over-fiber technology. It is intended for use in wireless personal area networks. However, we think that the same technology could be used for monitoring applications in the indoor environment. It could be used to detect emergency situations or to detect intruders. We shall examine reasons why this choice might be a suitable one. We shall then propose a MAC layer protocol to accomplish this task. Since in case of emergency we might require to obtain data from only one node for an extended duration, flexibility in implementation is required. We shall develop an adaptive MAC protocol where this would be possible. We accomplish this by including two protocol modes called the Icarus mode, which is to be used in case of an emergency and the Resync mode which is used when normality is restored. A significant problem at high frequencies is that the beam becomes increasingly narrow and behaves more in a ray like condition. This implies that particularly in an indoor environment it is possible that the beam may be accidentally blocked. In this case the node must be able shift the beam in order to enable communication. We demonstrate three such strategies and offer a comparative analysis.M.S.Committee Chair: Chang, Gee-Kung; Committee Member: Barry , John; Committee Member: Gaylord, To

Distributed multi-hop reservation scheme for wireless personal area ultra-wideband networks

Ultra-wideband (UWB) technology is a promising technology for multimedia applications in wireless personal area networks (WPANs) that supports very high data rates with lower power transmission for short range communication. The limitation of coverage radius of UWB network necessitates for multihop transmissions. Unfortunately, as the number of hops increases, the quality of service (QoS) degrades rapidly in multihop network. The main goal of this research is to develop and enhance multihop transmission that ensures QoS of real time traffic through the proposed distributed multihop reservation (DMR) scheme. The DMR scheme consists of two modules; distributed multihop reservation protocol (DMRP) and path selection. DMRP incorporates resource reservation, routing and connection setup that are extended on the existing WiMedia Media Access Control protocol (MAC). On the other hand, the path selection determines the optimal path that makes up the multihop route. The path selection selects nodes based on the highest Signal to Interference and Noise Ratio (SINR). The performance of DMR scheme has been verified based on the performance of the video traffic transmission. The main metrics of QoS are measured in terms of Peak Signal- to- Noise ratio (PSNR), End-to-End (E2E) delay, and throughput. The results show that DMRP compared to Multiple Resources Reservation Scheme (MRRS) in six (6) hops transmission has enhanced the average PSNR by 16.5%, reduced the average E2E delay by 14.9% and has increased the throughput by 11.1%. The DMR scheme which is the inclusion of path selection in DMRP has been compared to Link Quality Multihop Relay (LQMR). DMR scheme has improved the video quality transmission by 17.5%, reduced the average E2E delay by 18.6% and enhanced the average throughput by 20.3%. The QoS of six (6) hops transmission employing DMR scheme is almost sustained compared to two hops transmission with the QoS experiencing only slight degradation of about 2.0%. This is a considerable achievement as it is well known that as the number of hops increases the QoS in multihop transmission degrades very rapidly. Thus DMR scheme has shown to significantly improve the performance of real time traffic on UWB multihop network. In general, DMR can be applied to any WPAN network that exploit multihop transmission

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

Cost and energy efficient operation of converged, reconfigurable optical wireless networks

This paper presents a converged fibre-to-the-home (FTTH) based access network architecture featuring wireless services. In order to fulfill the bandwidth demands from end users, a dynamic architecture is proposed with co-existence of LTE, WiMax and UWB technologies. Hybrid wavelength division multiplexing (WDM) and a time division multiplexing (TDM) based optical access network offer reconfigurable provision. This enhances the ability to allocate different wavelengths to different optical networking units (ONUs) on demand. In addition, two different channel routing modules (CRMs) are introduced in order to address the cost effectiveness and energy efficiency issues of the proposed network. Take-up rate adaptive-mode operation and traffic-adaptive power management are utilized to optimize the benefits of low investment cost with energy efficiency. Up to 26% power consumption reduction is achieved at the time of minimum traffic conditions while 10% consumption is achieved at the time of maximum traffic conditions. Besides, 23% energy saving can be achieved compared to conventional systems in fully operated stage