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 17 of 17 for “"Spread Spectrum Communications"”.
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Power control for spread spectrum communications systems
Thesis (M. Eng.)--Massachusetts Institute of Technology, Dept. of Electrical Engineering and Computer Science, 1996.
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Efficient forward error correction coding technique for spread spectrum communications
This thesis presents the study of the coding technique and the simulation results for the Forward Error Correction (FEC) of the wireless data in a highly noisy and severe fading wireless medium, based on standard (IEEE 802.11 Wireless Local Area Network specification) and GPS driven non-standard …
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A frequency synthesizer for a 2.4 GHz spread spectrum communications application
Thesis (M. Eng.)--Massachusetts Institute of Technology, Dept. of Electrical Engineering and Computer Science, 1997.
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Ultra-wideband Spread Spectrum Communications using Software Defined Radio and Surface Acoustic Wave Correlators
… to coexist with previously allocated Federal Communications Commission (FCC) frequencies, simple transceiver architecture, and high performance in noisy environments. Spread spectrum techniques offer additional improvements beyond the conventional pulse-based UWB communications. This …
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The Performance of Direct-Sequence Spread-Spectrum Communications With Selective Fading Channels and Rake Reception
The performance of a direct-sequence spread-spectrum communication system is evaluated for selective fading channels and rake reception. Several issues are examined that influence the probability of error of the system, and closed-form expressions are obtained for the probability of error. The …
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Diversity Combining for Frequency-Hop Spread-Spectrum Communications With Partial-Band Interference and Fading (anti-Jam)
… 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 interference is modeled as a Gaussian process, although some of the results also …
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Time-Varying Autoregressive Model Based Signal Processing with Applications to Interference Rejection in Spread Spectrum Communications
… (FM) interference rejection in direct-sequence spread spectrum (DSSS) communications. For fast varying non-stationary signal processing, such as the task to reject an FM interference that could chirp over the entire DSSS bandwidth in a symbol interval, an explicit description of the variation is …
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Analysis, design, and fabrication of Archimedean spiral antennas
… antennas include wideband measurement systems, spread spectrum communications systems, feeds for reflectors and elements in wideband arrays. Here, wideband antennas are discussed and Archimedean spiral antennas are found to be appropriate elements for use in a new type of wideband array referred …
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Application of bit-slice microprocessors to digital correlation in spread spectrum communication systems
… to high-speed real-time digital correlation in spread spectrum and related communication applications. Spread spectrum communications are a wide-band secure communication system that generate a very broad spectral bandwidth signal that is therefore hard to detect in noise. They are capable of …
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Design, Analysis And Implementation Of Orthogonal Frequency Coding In Saw Devices Used For Spread Spectrum Tags And Sensors
… OFC offers all advantages inherent to spread spectrum communications including enhanced processing gain and lower interrogation power spectral density (PSD). It is shown that the time ambiguity in the OFC compressed pulse is significantly reduced as compared with a single frequency tag …
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SPREAD SPECTRUM SYNCHRONIZATION USING MATCHED FILTER AND CYCLIC ACCUMULATION
Direct sequence spread spectrum communications have become an increasingly popular technique over the decades. Code phase acquisition is a critical and difficult operation in any spread spectrum system. Acquisition must be accomplished within a short period of time and at low signal to noise ratio …
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Optimizing Wireless Network Throughput: Methods and Applications
… the air overseas about a century ago, wireless communications have experienced dramatic improvements. Today's world sees the penetration of wireless communications into human life almost everywhere, from a simple remote control for TV to a cellular phone. With a better understanding of the …
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Design and performance of CDMA codes for multiuser communications
… codes and are widely used in multiuser CDMA communications. Their popularity is due to the ease of implementation. Availability of these code sets is limited because of their generating kernels. Emerging radio applications like sensor networks or multiple service types in mobile and …
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Efficient Interference Cancellation Techniques for Advanced DS-CDMA Receivers
… in direct sequence code division multiple access communications. Emphasis is placed on the development of efficient techniques that are practical to implement. The work begins with a study of several sub-optimal multiuser detection techniques under a variety of conditions. Multistage parallel …
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Optimization of Soft Interference Cancellation in DS-CDMA Receivers
Parallel interference cancellation for DS-CDMA has been shown to suffer from biased amplitude estimates if a matched-filter estimator is used. The bias magnitude is proportional to the number of interfering users. For heavy system loads, the bias has been shown to adversely effect the accuracy of …
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Robustness of Modified FBMC-SS Against Partial-Band Noise-Like Interference
As spectrum has grown more congested, there has been a greater emphasis on interference-robust low-signal-to-noise ratio (SNR) waveforms capable of operating under interference from other users and under hostile jamming. Traditional robust waveforms have limitations of only being robust against …
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Resource allocation in realistic wireless cognitive radios networks
… provide an effective solution for improving spectrum usage for wireless users. In particular, secondary users can now compete with each other to access idle, unused spectrum from licensed primary users in an opportunistic fashion. This is typically done by using cognitive radios to sense the …