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.
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Showing 1 to 20 of 26 for “"Diversity combining"”.
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On performance analysis of optimal diversity combining with imperfect channel estimation
The optimal diversity combining technique is investigated for multipath Rayleigh and Ricean fading channel with additive white Gaussian noise where only imperfect channel knowledge is available at the receiver. The non-observable estimation error contributes as an additive source of noise which is …
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Four Branch Diversity Combining and Adaptive Beamforming Measurements Using Mobile Arrays at 2.05 GHz
Mobile arrays employing diversity combining and adaptive beamforming techniques overcome multipath fading, improve coverage, and increase capacity in wireless communications systems. In this thesis, diversity combining and adaptive beamforming performance of different four element arrays for mobile …
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Diversity Combining for Frequency-Hop Spread-Spectrum Communications With Partial-Band Interference and Fading (anti-Jam)
… presents results on the evaluation of several diversity combining techniques that are suggested for frequency-hop (FH) communications with partial-band interference and fading. The analysis covers systems with M -ary orthogonal signaling and noncoherent demodulation. The partial-band …
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The Effect of Population History on Hominoid Intraspecific Cranial Shape Diversity: Combining Population Genetic and 3D Geometric Morphometric Data
<p>Cranial shape diversity within hominoids has been previously studied with the aim of understanding how levels of diversity in extant species compare with extinct hominin specimens. This dissertation addresses the question of why cranial shape diversity differs among extant hominoids. Levels of …
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Optimum combining of handset diversity antennas
… due to dual-antenna systems with smart-antenna combining algorithms were determined. The performance of a mobile handset with a top-mounted monopole and back-mounted internal monopole was determined in the field. Handset field tests were conducted both for the handset attached to a phantom-head …
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Simulation of a Wireless Communication Channel to Determine a Best Topology for a Base Station Array Antenna
… high levels of interference. Even though a diversity combining scheme (MRC) was used in the simulator, the arrays provided interference rejection capabilities due to the closely spaced antenna elements. Though diversity does provide a gain in received signal, relative to the faded signal, …
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Diversity with practical channel estimation in arbitrary fading environments
… the bit error probability of Nd-branch diversity combining in the presence of non-ideal channel estimates. The estimator structure is based on the maximum likelihood (ML) estimate and arises naturally as the sample mean of Np pilot symbols. The framework presented requires only the …
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New Results on Selection Diversity over Fading Channels
… rate performance of five different selection diversity combining schemes over slow, frequency non-selective Rayleigh, Nakagami-m and Ricean fading channels. Aside from the classical selection diversity, generalized selection combining and the "maximum output" selection methods, two new …
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Simulation of Third Generation CDMA Systems
… at the front end of the receiver. Simple rake diversity combining is employed at the receiver. We investigate the bit error rate at both uplink and downlink for different channel conditions. Performance improvement due to error correction coding scheme is shown. The simulator developed can be …
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Performance analysis of the Link-16/JTIDS waveform with concatenated coding, soft decision Reed Solomon decoding and noise-normalization
… code is considered. In addition, a sequential diversity of two, consistent with the JTIDS double-pulse structure, is considered both for soft decision (SD) RS decoding and for soft diversity combining with noise-normalization. Both coherent and noncoherent detection are considered. Based on the …
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Cooperative relaying in cellular networks for improving receiver diversity and cell radius
… (relays) exploit a larger form of space diversity to relay signals to destinations when placed in between source and destination to combat the effects of fading induced by multipath signal propagation. However, the position of the relay in between the source and destination plays a …
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Weak GPS Signal Acquisition Using Antenna Diversity
… non-coherent and differentially coherent combining methods are not effective in dense multipath fading situations where the carrier-to-noise ratio (C/N0) varies significantly. Spatial antenna diversity provides additional processing gain to overcome multipath fading since multiple antennas …
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Differential MMSE: A New Approach for Adaptive Interference Suppression Over Time-Varying Channels
… MMSE receiver provides automatic multipath combining for slow fading rates. For faster fading rates, it is necessary to extend the differential MMSE criterion to provide explicit multipath combining. A number of such extensions are proposed, notable among which is the eigen-rake receiver, …
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Adaptive Arrays and Diversity Antenna Configurations for Handheld Wireless Communication Terminals
… into the performance of adaptive beamforming and diversity combining using antenna arrays that can be mounted on handheld radios. Handheld arrays show great promise for improving the coverage, capacity, and power efficiency of wireless communication systems. Diversity experiments using a handheld …
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Performance Evaluation of Equal Gain Diversity Systems In Fading Channels
… link access to information infrastructure. Diversity techniques play a vital role in supporting such high speed connections over radio channels by mitigating the detrimental effects of multiuser interference and multipath fading. Equal gain combining (EGC) diversity receiver is of practical …
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Cross-layer design for wireless sensor relay networks
… by the multipath utilization and transmit diversity capability of space-time block codes (STBC), a new energy efficient cooperative routing algorithm using the STBC is proposed. Furthermore, the steady state performance of the network is analyzed via a Markov chain model. The proposed …
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Spectrum sensing, spectrum monitoring, and security in cognitive radios
… in the presence of fading where the SU employs diversity combining to mitigate the channel fading effects. We show that a decision statistic based on the REC alone does not provide a good performance. Next we introduce new decision statistics based on the REC and the combiner coefficients. It is …
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Cooperative diversity aided direct-sequence code-division multiple-access systems
… from the relays are detected based on a range of diversity combining schemes having a relatively low-complexity. Specifically, the maximal ratio combining (MRC), the maximum signal-to-interference-plus-noise ratio (MSINR) and the minimum mean-square error (MMSE) principles are considered.<br/>We …
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Improving the Performance of Wireless Systems via Selective Interference Nulling and Adaptive Medium Access Control Design
… interference nulling (SIN) and maximal ratio combining (MRC) in mobile radio environments is developed. In the second part of this thesis, we explore the performance gains that can be achieved by exploiting the synergy resulting from the combination of the MAC and the physical layer of a …
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