Multivariate statistics play an important role in performance analysis of wireless communication systems in correlated fading channels. This thesis presents a framework which can be used to derive easily computable mathematical representations for some multivariate statistical distributions, which are derivatives of the Gaussian distribution, and which have a particular correlation structure. The new multivariate distribution representations are given as single integral solutions of familiar mathematical functions which can be evaluated using common mathematical software packages. The new approach can be used to obtain single integral representations for the multivariate probability density function, cumulative distribution function, and joint moments of some widely used statistical distributions in wireless communication theory, under an assumed correlation structure. The remarkable advantage of the new representation is that the computational burden remains at numerical evaluation of a single integral, for a distribution with an arbitrary number of dimensions. The new representations are used to evaluate the performance of diversity combining schemes and multiple input multiple output systems, operating in correlated fading channels. The new framework gives some insights into some long existing open problems in multivariate statistical distributions. / Communications

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International Telemetering Conference Proceedings / October 25-28, 1999 / Riviera Hotel and Convention Center, Las Vegas, Nevada / This paper describes the design, configuration, testing, and performance of a Fiber Optic Link used to transmit the signals from a remotely located S-band telemetry system to the main facility at the Kwajalein Missile Range (KMR). This fiber optic system demonstrates for the first time the feasibility of linking RF data from multiple antennas via a single fiber and over a nearly 100-km distance. Measured data of key link parameters such as gain, bit-error-rate, crosstalk, phase and gain stability, dynamic range, and noise figure are presented.

International Telemetering Conference Proceedings / October 22-25, 2001 / Riviera Hotel and Convention Center, Las Vegas, Nevada / Telemetry support has been a component of the instrumentation test support structure at Kwajalein Missile Range (KMR) for nearly 40 years. From a limited initial suite of manually pointed telemetry antennas, the Range has grown to include nine tracking antennas and four fixed receiving antennas. This paper describes the current modernization program at KMR that will include nine new telemetry trackers and five fixed antennas that will be networked and controlled via fiber optic links from a newly established telemetry control center on the island of Kwajalein. These upgrades will reduce operational cost and institute efficiencies, while continuing to meet Range Users’ growing requirements.

This thesis covers the investigation and application of continuous spatial models for multiple antenna signal processing. The use of antenna arrays for advanced sensing and communications systems has been facilitated by the rapid increase in the capabilities of digital signal processing systems. The wireless communications channel will vary across space as different signal paths from the same source combine and interfere. This creates a level of spatial diversity that can be exploited to improve the robustness and overall capacity of the wireless channel. Conventional approaches to using spatial diversity have centered on smart, adaptive antennas and spatial beam forming. Recently, the more general theory of multiple input, multiple output (MIMO) systems has been developed to utilise the independent spatial communication modes offered in a scattering environment.¶ Underlying any multiple antenna system is the basic physics of electromagnetic wave propagation. Whilst a MIMO system may present a set of discrete inputs and outputs, each antenna element must interact with the underlying continuous spatial field. Since an electromagnetic disturbance will propagate through space, the field at different positions in the space will be interrelated. In this way, each position in the field cannot assume an arbitrary independent value and the nature of wave propagation places a constraint on the allowable complexity of a wave-field over space. To take advantage of this underlying physical constraint, it is necessary to have a model that incorporates the continuous nature of the spatial wave-field. ¶This thesis investigates continuous spatial models for the wave-field. The wave equation constraint is introduced by considering a natural basis expansion for the space of physically valid wave-fields. This approach demonstrates that a wave-field over a finite spatial region has an effective finite dimensionality. The optimal basis for representing such a field is dependent on the shape of the region of interest and the angular power distribution of the incident field. By applying the continuous spatial model to the problem of direction of arrival estimation, it is shown that the spatial region occupied by the receiver places a fundamental limit on the number and accuracy with which sources can be resolved. Continuous spatial models also provide a parsimonious representation for modelling the spatial communications channel independent of specific antenna array configurations. The continuous spatial model is also applied to consider limits to the problem of wireless source direction and range localisation.

Dual-hop transmission system can increase the transmission diversity via the cooperation of transmission nodes and can also overcome the channel fading effectively. This thesis proposes an outage probability analysis method for the AF relaying system where multiple antennas are equipped at source node and both the relay node and destination node just carry single antenna. Compare with previous work, the average signal to noise ratio of source to relay and relay to destination links are assumed to be two different variables, therefore we can get a more general performance analysis. We also extend our theoretical analysis to the system where multiple antennas are utilized at destination node. Simulation results are shown to verify the analysis of the proposed schemes in some representative scenarios.

In this dissertation, the problem of symbol timing synchronization for the following three different communication systems is studied: 1) conventional single-carrier transmissions with single antenna in both transmitter and receiver; 2) single-carrier transmissions with multiple antennas at both transmitter and receiver; and 3) orthogonal frequency division multiplexing (OFDM) based IEEE 802.11a wireless local area networks (WLANs). For conventional single-carrier, single-antenna systems, a general feedforward symbol-timing estimation framework is developed based on the conditional maximum likelihood principle. The proposed algorithm is applied to linear modulations and two commonly used continuous phase modulations: MSK and GMSK. The performance of the proposed estimator is analyzed analytically and via simulations. Moreover, using the newly developed general estimation framework, all the previously proposed digital blind feedforward symbol timing estimators employing second-order statistics are cast into a unified framework. The finite sample mean-square error expression for this class of estimators is established and the best estimators are determined. Simulation results are presented to corroborate the analytical results. Moving on to single-carrier, multiple-antenna systems, we present two algorithms. The first algorithm is based on a heuristic argument and it improves the optimum sample selection algorithm by Naguib et al. so that accurate timing estimates can be obtained even if the oversampling ratio is small. The performance of the proposed algorithm is analyzed both analytically and via simulations. The second algorithm is based on the maximum likelihood principle. The data aided (DA) and non-data aided (NDA) ML symbol timing estimators and their cor- responding CCRB and MCRB in MIMO correlated ??at-fading channels are derived. It is shown that the improved algorithm developed based on the heuristic argument is just a special case of the DA ML estimator. Simulation results under different operating conditions are given to assess and compare the performances of the DA and NDA ML estimators with respect to their corresponding CCRBs and MCRBs. In the last part of this dissertation, the ML timing synchronizer for IEEE 802.11a WLANs on frequency-selective fading channels is developed. The proposed algorithm is compared with four of the most representative timing synchronization algorithms, one specically designed for IEEE 802.11a WLANs and three other algorithms designed for general OFDM frame synchronization.

Global mobile data traffic has more than doubled in the past four years, and will only increase throughout the upcoming years. Modern cellular systems are striving to enable communications at high data rates over wide geographical areas to meet the surge in data demand. This requires advanced technologies to mitigate fundamental effects of wireless communications like path-loss, shadowing, small-scale fading, and interference. Two of such technologies are: i) deploying multiple antennas at the transmitter and receiver, and ii) employing an extra radio, called the relay, to forward messages from the transmitter to the receiver. The advantages of both technologies can be leveraged by using multiple antennas at the relay, transmitter, and receiver. Multiple-antenna relay-assisted communication is emerging as one promising technique for expanding the overall capacity of cellular networks. Taking full advantage of multiple-antenna relay-assisted cellular systems requires transmission strategies for jointly configuring the transmitters and receivers based on knowledge of the wireless propagation medium. This dissertation proposes such transmission strategies for wireless multiple-antenna relay-assisted systems. Two popular types of relays are considered: i) amplify-and-forward relays (the relays simply apply linear signal processing to their observed signals before retransmitting) and ii) decode-and-forward relays (the relays decode their observed signals and then re-encode before retransmitting). The first part of this dissertation considers the three-node multiple-antenna amplify-and-forward relay channel. Algorithms for adaptively selecting the number of data streams and subsets of transmit antennas at the transmitter and relay to provide reliable transmission at a guaranteed rate are proposed. Expressions for extracting spatial characteristics of the end-to-end multiple-antenna relay channel are derived. The second part of the dissertation presents interference management strategies that are developed specifically for two models of multiple-antenna relay interference channels where a number of relays assist multiple transmitters to communicate with multiple receivers. One model uses amplify-and-forward relays while the other uses decode-and-forward relays. Based on the idea of interference alignment, these strategies aim at maximizing the sum of achievable end-to-end rates. Simulation results show that the proposed transmission strategies with multiple-antenna relays achieve higher capacity and reliability than both those without relays and those with single-antenna relays. / text

Next generation wireless systems will use multiple antenna technologies, also known as multiple-input multiple-output (MIMO), to provide high data rates and robustness against fading. MIMO communication strategies for single user communication systems and their practical application in wireless networks are by now well known. MIMO communication systems, however, can benefit from multiuser processing by coordinating the transmissions to multiple users simultaneously. For numerous reasons, work on the theory of multiuser MIMO communication has yet to see broad adoption in wireless communication standards. For example, global knowledge of channel state information is often required. Such an unrealistic assumption, however, makes it difficult in practice to implement precoding techniques. Furthermore, the achievable rates of the conventional multiuser MIMO techniques are far from the theoretical performance bounds. These and other factors motivate research on practical multiuser communication strategies for the MIMO broadcast channel (point to multi-point communication) and the analysis of those strategies. The primary contributions of this dissertation are i) the development of four novel low complexity coordinated MIMO transceiver design techniques to approach the theoretical performance bound and ii) the investigation of the optimality of the proposed coordinated wireless MIMO networks. Several coordinated beamforming algorithms are proposed, where each mobile station uses quantized combining vectors or each base station uses limited feedback from the MS. The asymptotic optimality of the proposed coordinated beamforming system for the MIMO Gaussian broadcast channel is next investigated. For multi-stream transmission, a novel block diagonalized vector perturbation is proposed and the achievable sum rate upper bound of the proposed system is derived. Finally, for multi-cell environments, linear and non-linear network CBF algorithms supporting multiple cell-boundary users are proposed. The optimality of network coordinated beamforming in terms of the number of receive antennas is also investigated. / text

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