Global ETD Search
Search theses and dissertations gathered from participating repositories worldwide. Every result links back to the library that holds it. No account is needed.
Results
Showing 1 to 20 of 48 for “"Multipath propagation"”.
-
A statistical ultra wideband indoor channel model and the effects of antenna directivity on multipath delay spread and path loss in ultra wideband indoor channels
… effects of antenna directivity on path loss and multipath propagation in the channel were analyzed extensively for various omni-directional and directional antenna combinations. A statistical model of the path loss in the channel is presented, where the parameters in the model (i.e., path loss …
-
An investigation into non-linear propagation of MSK with a view to specifying an adaptive equalizer
… is to investigate the effects of non-linear propagation on a proposed digital microwave radio link which employs MSK modulation, in order to specify a suitable form of adaptive equalization. MSK is a coherent modulation technique, having improved spectral roll-off over FSK because it avoids …
-
Resolution of signal components of a resultant electromagnetic wave received in a multipath field of microwave frequencies
… of potential obstacles increase the risk of multipath propagation. Multipath propagation on radio links is associated with signal delays and signal level fades on which adversely influences the system performance.<br/><br/>For efficient frequency planning the knowledge of the multipath …
-
A Novel Diversity Technique to Improve the Channel Coding Performance in Wireless Communications
… the major performance degradation factors is the multipath propagation phenomenon which leads to fading problem and unreliable system. The multipath propagation phenomenon results in, copies of the transmitted signal are travelled over different paths. The replicas can undergo various time delays …
-
A multistage RAKE receiver for CDMA systems
… of a RAKE receiver in the presence of multipath interference. Unlike previous multiuser receiver designs, this multistage RAKE receiver requires no a priori information about the time-vary multipath radio channel. The thesis presents a mathematical description of the multistage …
-
Performance analysis of subaperture processing using a large aperture planar towed array
… in these regions is complicated by strong multipath propagation with high transmission loss. Large aperture planar arrays have the potential to improve detection performance due to their high resolution and high gain, but are suceptible to two main performance degradation mechanisms: …
-
A Propagation Simulator for Land Mobile Satellite Communications
… communications link can be determined by the propagation path between a satellite and mobile users. Some of the most important factors are multipath propagation and vegetative shadowing. System designers should have the most reliable information about the statistics of fade duration in order …
-
Fade durations in satellite-path mobile radio propagation
… several factors, the most important of which are multipath propagation and vegetative shadowing. Designers of vehicular satellite communications systems require information about the statistics of fade durations in order to overcome or compensate for the fades. Except for a few limiting cases, …
-
Wideband propagation measurements for personal communication systems
The propagation channel is a vital but invisible part of any wireless communications system. As wavelengths get shorter, multipath effects become more pronounced, causing small scale fading in narrowband channels, and inter-symbol interference in wideband systems because of delay spread in the …
-
Efficient forward error correction coding technique for spread spectrum communications
… the coding scheme is assessed in Rayleigh fading multipath propagation with additive white Gaussian noise interference coupled with interference due to like user frequency hop overlapping (in non-standard MAC scheme). Simulation results for severe fading channel with burst error models are …
-
Fundamental limits of wideband localization
… is a challenging task, especially in harsh multipath propagation environments. To address this problem, wide bandwidth signals are envisioned to be used in future localization systems, since such signals can provide accurate range measurements. In this paper, we investigate the localization …
-
Rate selection for MIMO links
… at the transmitters and receivers, as well as multipath propagation, to provide more reliable, higher capacity wireless links. As a result, these links can support a set of much higher data rates than single-input single-output (SISO) links. However, it is not always optimal for a node to …
-
MIMO MC-CDMA Systems over indoor optical wireless communication channels
… to natural and artificial light sources and multipath propagation. The former degrades the signal to noise ratio while the latter limits the maximum achievable data rate. This thesis investigates the use of transmit power adaptation in the design of optical wireless spot-diffusing systems to …
-
Modulation techniques for data superposition on amplitude-modulated signals
… The cross-talk between the two channels due to multipath propagation is considered to be a limiting factor. A novel complex filtering technique to detect complex zeros of realsignals is introduced and discussed. The distribution of the complex zeros of positive bandlimited signals is assessed …
-
Efficient Array Processing for Partial Signal Coherence
… degradation can be attributed to either complex multipath propagation or to mechanical deformations in the array itself. Optimally dealing with partial signal coherence typically requires modeling the array response as random, leading to complicated combining schemes to achieve optimal …
-
An adaptive multistage interference cancellation receiver for CDMA
… of channel models including Gaussian noise, MAI, multipath propagation and near-far effects. Simulation results demonstrate the robustness of the Multistage Rake receiver to near-far effects and manifold capacity improvement compared to conventional demodulation techniques.
-
Algorithms for indoor localization based on IEEE 802.15.4-2011 UWB and inertial sensors
… arrival measurements for ranging applications. A multipath propagation controlling technique is synthesized which considers the relationship between transmit power, transmission range and signal-to-noise ratio. The methodology includes a novel bilateral transmitter output power control algorithm …
-
An investigation into the performance of a power-of-two coefficient transversal equalizer in a 34Mbit/s QPSK digital radio during frequency-selective fading conditions
Under certain atmospheric conditions, multipath propagation can occur. The interaction of radio waves arriving at a receiver, having travelled via paths of differing length, results in the phenomenon of frequency-selective fading. This phenomenon manifests as a notch in the received spectrum and …
-
Site-specific propagation prediction for wireless in-building personal communication system design
… describes a geometrical optics model to predict propagation in buildings for personal communication system (PCS) design. Background on the growth of wireless communications is given, and the importance of accurate propagation models is discussed. The peculiarities of propagation in mobile and …
-
Microcellular radio channel prediction using ray tracing
… lines to connect communication terminals. The propagation characteristics of radio frequency signals on these transmission lines are well known. In wireless communication systems, however, the transmission line with a known impulse response is replaced by a radio channel with an impulse …
Page 1 of 3