Adaptive Antenna Arrays for Ad-Hoc Millimetre-Wave Wireless Communications

New technologies that employ millimetre-wave frequency bands to achieve high speed wireless links are gaining more attention (Dyadyuk et. al., 2007, 2009b, 2010a; Hirata et. al., 2006; Lockie & Peck, 2009; Kasugi et. al., 2009; Wells, 2009) due to increasing demand for wideband wireless communications. Very wide uncongested spectrum is available in the E—bands (71-76 GHz and 81-86 GHz) recently allocated for wireless communications in USA, Europe, Korea, Russia and Australia. The E-band provides an opportunity for line-of – sight (LOS) links with higher data rates, well suited for fibre replacement and backhaul applications. Future mobile and ad-hoc communications networks will require higher bandwidth and longer range. An ad-hoc or mobile (e.g. inter-aircraft) network that relies on high gain antennas also requires beam scanning. Adaptive antenna arrays have found a wide rage of applications and are becoming essential parts of wireless communications systems (Abbaspour-Tamijani & Sarabandi, 2003; Do-Hong & Russer, 2004; Gross, 2005; Guo, 2004; Krim & Viberg, 1996; Mailloux, 2005, 2007; Rogstad et al., 2003; Singh et al., 2008). While the spectrum available in the millimetre-wave frequency bands enables multi-gigabit-per second data rates, the practically achievable communication range is limited by several factors. These include the higher atmospheric attenuation at these frequencies and limited output power of monolithic microwave integrated circuits (MMIC) (Doan et al., 2004; Dyadyuk et al., 2008a; Kasper et al., 2009; Floyd et al., 2007; Reynolds et. al., 2006; Vamsi et. al., 2005, Zirath et al., 2004) due to physical constraints. Therefore, the performance of the ad-hoc or mobile millimetre-wave networks requires enhancement by using spatial power combining antenna arrays

Millimeter wave wireless system based on point to multipoint transmissions

The continuously growing traffic demand has motivated the exploration of underutilized millimeter wave frequency spectrum for future mobile broadband communication networks. Research activities focus mainly on the use of the V-band (59 - 64 GHz) and E-band (71 - 76 & 81 - 84 GHz) to offer multi-gigabit point to point transmissions. This paper describes an innovative W-band (92-95 GHz) point to multipoint wireless network for high capacity access and backhaul applications. Point to multipoint wireless networks suffer from limited RF power available. The proposed network is based on a high power, wide band traveling wave tube of new generation and an affordable high performance transceiver. These new devices enable a new transmission paradigm and overcome the relevant technological challenges imposed by the high atmosphere attenuation and the presently lack of power amplification required to provide adequate coverage at millimeter waves

Towards a multiservice & multiformat optical home area networks

International audienceWe propose mid and long term visions of optical Home Area Networks. The challenge is not only to increase the network capacity, but also to take into account the heterogeneity of the signals to be conveyed: Ethernet, RF TV and radio signals for wireless-end-connectivity. Two solutions are described: a mid term solution, based on an active star and centered on a multiformat switch, and a long term solution based on a fully transparent infrastructure, associated with optical wavelength multiplexing. These solutions and the corresponding realized setups will be described and compared in terms of performances, flexibility and robustness to future evolutions

Convergence of millimeter-wave and photonic interconnect systems for very-high-throughput digital communication applications

In the past, radio-frequency signals were commonly used for low-speed wireless electronic systems, and optical signals were used for multi-gigabit wired communication systems. However, as the emergence of new millimeter-wave technology introduces multi-gigabit transmission over a wireless radio-frequency channel, the borderline between radio-frequency and optical systems becomes blurred. As a result, there come ample opportunities to design and develop next-generation broadband systems to combine the advantages of these two technologies to overcome inherent limitations of various broadband end-to-end interconnect systems in signal generation, recovery, synchronization, and so on. For the transmission distances of a few centimeters to thousands of kilometers, the convergence of radio-frequency electronics and optics to build radio-over-fiber systems ushers in a new era of research for the upcoming very-high-throughput broadband services. Radio-over-fiber systems are believed to be the most promising solution to the backhaul transmission of the millimeter-wave wireless access networks, especially for the license-free, very-high-throughput 60-GHz band. Adopting radio-over-fiber systems in access or in-building networks can greatly extend the 60-GHz signal reach by using ultra-low loss optical fibers. However, such high frequency is difficult to generate in a straightforward way. In this dissertation, the novel techniques of homodyne and heterodyne optical-carrier suppressions for radio-over-fiber systems are investigated and various system architectures are designed to overcome these limitations of 60-GHz wireless access networks, bringing the popularization of multi-gigabit wireless networks to become closer to the reality. In addition to the advantages for the access networks, extremely high spectral efficiency, which is the most important parameter for long-haul networks, can be achieved by radio-over-fiber signal generation. As a result, the transmission performance of spectrally efficient radio-over-fiber signaling, including orthogonal frequency division multiplexing and orthogonal wavelength division multiplexing, is broadly and deeply investigated. On the other hand, radio-over-fiber is also used for the frequency synchronization that can resolve the performance limitation of wireless interconnect systems. A novel wireless interconnects assisted by radio-over-fiber subsystems is proposed in this dissertation. In conclusion, multiple advantageous facets of radio-over-fiber systems can be found in various levels of end-to-end interconnect systems. The rapid development of radio-over-fiber systems will quickly change the conventional appearance of modern communications.PhDCommittee Chair: Gee-Kung Chang; Committee Member: Bernard Kippelen; Committee Member: Shyh-Chiang Shen; Committee Member: Thomas K. Gaylord; Committee Member: Umakishore Ramachandra

Semiconductor Optical Amplifiers and mm-Wave Wireless Links for Converged Access Networks

Future access networks are converged optical-wireless networks, where fixed-line and wireless services share the same infrastructure. In this book, semiconductor optical amplifiers (SOA) and mm-wave wireless links are investigated, and their use in converged access networks is explored: SOAs compensate losses in the network, and thereby extend the network reach. Millimeter-wave wireless links substitute fiber links when cabling is not economical