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One of the advantages of multiple-input multiple-output (MIMO) systems is the multiplexing gain over single-input single-output (SISO) systems. We consider adaptive modulation and coding (AMC) as a practical technique in achieving the full multiplexing gain of MIMO systems. The multiplexing gain of AMC MIMO systems is analyzed quantitatively, and a practical way of predicting the multiplexing gain...
Advances in information and communications technology have enabled the adoption of wireless communication techniques in all sectors for the transmission of information in all forms between any two points. Wireless communications and distributed computing have promoted the development of vehicle- monitoring systems to reduce the maintenance and inspection requirements of railway systems while maintaining...
Although DGPS provides positioning information with high precision, when DGPS is unavailable in some situations, stand-alone GPS has to be used in vehicle navigation. The accuracy of standard GPS is low due to position measurement errors. This paper presents a frequency domain modeling approach to model GPS errors and increase GPS positioning accuracy. This approach models GPS errors using shaping...
In this paper, a receiver algorithm for an 8x8 MIMO system is considered for Giga-bps data transmission, in which the decoding complexity and latency are crucial factors for implementation of MIMO system with large number of transmit and receive antennae. To reduce computational complexity and the decoding latency, a 3-stage receiver algorithm is proposed. The MIMO receiver consists of multidimensional...
This paper reports on experiences in simulating distributed localisation in a cooperative oriented sensors actuators network. We built and tested three different modules of a simulator: creation of constellations, node position approximation and modeling of error propagation in the network. In our approach we modelled neighbourhood as a local abstraction moderated by two global aspects: average position...
Major envisioned commercial ultra wideband (UWB) applications are indoor, nonetheless, the suitability of UWB technology for data communication over longer ranges may also have a relevant role in the outdoor wireless communications. In this paper we evaluate and compare the achievable range-data rate performance of a reliable UWB communication link for long ranges, considering an Impulse Radio UWB...
In this paper, we study the minimum-mean-squared- error feedback precoder (MMSE-FBP) for the multiple-input multiple-output (MIMO) Gaussian broadcast channel (BC). It has recently been shown that MMSE-FBP can achieve higher sum capacity than zero-forcing and MMSE precoders, however, it still leaves a gap to the MIMO BC sum capacity. We propose two new schemes involving dynamic power allocation among...
The proliferation of laptops, cellular phones, and other mobile computing platforms connected to the Internet has triggered numerous research works into mobile networking. The increasingly dense set of wireless access networks that can be potentially accessed by mobile users open the door to an era of pervasive computing. However, the puzzle of wireless access networks that tends to become the natural...
In this work reliability issues regarding a new SIP-based architecture for location tracking are investigated. This new architecture works across different positioning technologies (particle filters and GPS) and provides optimal position tracking in real time for an outdoor mobile user. A new adaptive SIP retransmission timer is proposed that is designed specifically for real time location tracking...
Modern systems require transceivers that deliver gigabit speeds, are smaller in size, and have lower power consumption and cost. This motivates research to develop transceiver-on-chip and transceiver-in-a-package technologies. Recent advances in millimetre wave electronics have meant that significant portions of the system can now be integrated onto a single substrate or package. In order to achieve...
It was found that, the frequency hopping, FH, technique minimizes sensitivity of radar system to jamming and interference and may solve some of the ambiguity and resolution problems. In the present work, at first, a theoretical introductory to summarize the subject of FH technique, slow frequency hopping (SFH) as well as fast frequency hopping (FFH) is given. Fast frequency hopping will be considered...
With the introduction of millimetre wave radar systems in various commercial applications, including collision avoidance, cruise control, autonomous navigation and imaging, it is now clear that a "one size fits all" approach to radar system development is not effective. This paper describes the implementation of a reconfigurable millimetre wave system comprising a coherent 94 GHz front end,...
An ad hoc network is a collection of mobile nodes that dynamically form a temporary network. It operates without the use of existing infrastructure. One of the principal routing protocols used in ad-hoc networks is AODV (ad-hoc on demand distance vector) protocol. The security of the AODV protocol is compromised by a particular type of attack called 'black hole' attack. In this attack a malicious...
Many of the requirements for autonomous sensing of moving vehicles are the same as those for automatic cruise control radars, whose development is now sufficiently mature to be on offer to the consumer car market. This paper investigates the suitability of these radars for use on an autonomous vehicle, and describes a capability assessment of two specific radars for such a task.
The parameter energy link loss between the source of the transmitter and the load of the receiver is used to evaluate the performance of a ultrawideband (UWB) radio system. The rigorous calculation of the link loss in a UWB system is a complicated task. However, for the special cases of two similar small antennas (dipoles and loops) a simple approximate analytical estimation of this parameter can...
This paper presents a new TR-UWB receiver using correlation in the frequency domain. Correlation is performed on the real and imaginary frequency-components of UWB pulses, respectively and correlation results are combined to enhance the output SNR. Analytical and numerical derivations are presented.
Most of the existing UWB models are extensions of narrowband models. These models suffer from limitations because UWB multipath propagation is frequency and antenna dependent. In this paper, a directional simulator based on TEM horn antenna is developed. This simulator illustrates the spatial impact on the received multipath profiles. Several deterministic scenarios are simulated to examine the antenna...
Universal mobile telecommunication system (UMTS) networks rely on the performance of power control algorithms in use. The conventional power control in UMTS is a fixed stepsize algorithm which can achieve only limited performance. A number of advanced power control techniques have been presented in the literature. However, it is difficult to compare the performance of algorithms from different literature...
This paper proposes an improved single frequency estimator for flat fading channels. The proposed carrier frequency offset (CFO) estimator decreases the number of computations in the calculation of the autocorrelation function (AF) when compared to AF-based conventional estimators. The results shown that the proposed estimator achieves better performance than the existing estimators. Furthermore,...
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