Air Interface Standard Research Articles

Assessing Perceptual Video Quality in Wimax Networks

This paper presents an approach for assessing the perceptual quality of wireless video networking applications transmitted via WiMAX, the Worldwide Interoperability for Microwave Access air interface standard. The Video Quality Model developed by Information Administration’s Video Quality Expert Group is used to benchmark perceptual video quality.

Assessing Perceptual Video Quality in Wimax Networks

This paper presents an approach for assessing the perceptual quality of wireless video networking applications transmitted via WiMAX, the Worldwide Interoperability for Microwave Access air interface standard. The Video Quality Model developed by Information Administration’s Video Quality Expert Group is used to benchmark perceptual video quality.

Design and performance of an all‐Internet Protocol mobile satellite system

SummaryThird and Fourth Generation (3G and 4G) terrestrial systems provide higher speed Internet Protocol multimedia services to end‐users with differentiated QoS across applications. To facilitate this, terrestrial architectures are moving towards an end‐to‐end all‐IP architecture that unifies all services, including Voice over IP bearer. In parallel, Mobile Satellite Systems (MSS) are being designed to complement and/or co‐exist with terrestrial coverage depending on spectrum sharing rules and operator choice. The challenge for MSS designers is to address the different physical layer characteristics while maintaining interoperability and compatibility with terrestrial services and reuse 3G Partnership Project core networks.To this end, MSS have been developed that mirror terrestrial Second Generation, 2.5G and 3G systems and are already operational in different parts of the world using different orbital constellations from low Earth orbits to geostationary orbits and both proprietary and standardized air interfaces. This paper describes architectures and methods for mobile satellite systems to achieve services similar to 3G and Fourth Generation terrestrial systems, focusing on the European Telecommunications Standards Institute Geostationary‐Mobile Radio GMR‐1 3G satellite air interface standard. Copyright © 2015 John Wiley & Sons, Ltd.

Enhanced random access and reservation scheme in CDMA2000

The growing demand for high-speed packet data services and multimedia applications over mobile personal communication networks has set new design requirements and objectives for the next generation of air interface protocols. The asymmetric and bursty nature of multimedia packet data traffic, and the variability of data rates, packet sizes, and quality of service requirements make conventional voice-oriented channelization and access protocols inefficient. New media access control and common channel messaging procedures need to be defined to efficiently support concurrent multiple packet- and circuit-switch-based services and their related signaling messages. Specifically, the role of common channels in support of frequent short packet data and signaling transactions is much more significant. This article presents the new enhanced random access and reservation schemes in CDMA2000 as well as related concepts considered in the design of the current and future releases of this air interface standard. The scheme is based on a variation of packet reservation multiple access combined with variable data rate, power control and soft handoff capabilities, formalized within wideband CDMA2000 framework.

Smart antennas for combined DOA and joint channel estimation in time-slotted CDMA mobile radio systems with joint detection

In cellular mobile radio systems, the directional inhomogeneity of the mobile radio channel can be exploited by smart antennas to increase the spectral efficiency. In this paper, a novel smart antenna concept applying receiver antenna diversity at the uplink receiver is investigated for a time-slotted code-division multiple-access (CDMA) mobile radio air interface termed time-division CDMA (TD-CDMA), which has been selected by the European Telecommunications Standards Institute (ETSI) in January 1998 to form part of the Universal Mobile Telecommunications System (UMTS) air interface standard. First, a combined direction-of-arrival (DOA) and joint channel estimation scheme is presented, which is based on DOA estimation using the Unitary ESPRIT algorithm and maximum likelihood estimation of the channel impulse responses associated with the estimated DOA's, which can also be used as an input for advanced mobile positioning schemes in UMTS. The performance of the combined DOA and joint channel estimation is compared with the conventional channel estimation through simulations in rural and urban propagation environments. Moreover, a novel joint data detection scheme is considered, which explicitly takes into account the signal DOA's and the associated channel impulse responses. The link level performance of a TD-CDMA mobile radio system using these novel schemes is evaluated by Monte Carlo simulations of data transmission, and average bit error rates (BER's) are determined for rural and urban propagation environments. The simulation results indicate that, depending on the propagation environment, the exploitation of the knowledge of the directional inhomogeneity of the mobile radio channel can lead to considerable system performance enhancements.