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You searched for subject:(Spectral regrowth). Showing records 1 – 3 of 3 total matches.

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Georgia Tech

1. Ding, Lei. Digital Predistortion of Power Amplifiers for Wireless Applications.

Degree: PhD, Electrical and Computer Engineering, 2004, Georgia Tech

Digital predistortion is one of the most cost effective ways among all linearization techniques. However, most of the existing designs treat the power amplifier as a memoryless device. For wideband or high power applications, the power amplifier exhibits memory effects, for which memoryless predistorters can achieve only limited linearization performance. In this dissertation, we propose novel predistorters and their parameter extraction algorithms. We investigate a Hammerstein predistorter, a memory polynomial predistorter, and a new combined model based predistorter. The Hammerstein predistorter is designed specifically for power amplifiers that can be modeled as a Wiener system. The memory polynomial predistorter can correct both the nonlinear distortions and the linear frequency response that may exist in the power amplifier. Real-time implementation aspects of the memory polynomial predistorter are also investigated. The new combined model includes the memory polynomial model and the Murray Hill model, thus extending the predistorter's ability to compensate for strong memory effects in the power amplifier. The predistorter models considered in this dissertation include both even- and odd-order nonlinear terms. By including these even-order nonlinear terms, we have a richer basis set, which offers appreciable improvement. In reality, however, the performance of a predistortion system can also be affected by the analog imperfections in the transmitter, which are introduced by the analog components; mostly analog filters and quadrature modulators. There are two common configurations for the upconversion chain in the transmitter: two-stage upconversion and direct upconversion. For a two-stage upconversion transmitter, we design a band-limited equalizer to compensate for the frequency response of the surface acoustic wave (SAW) filter which is usually employed in the IF stage. For a direct upconversion transmitter, we develop a model to describe the frequency-dependent gain/phase imbalance and dc offset. We then develop two methods to construct compensators for the imbalance and dc offset. These compensation techniques help to correct for the analog imperfections, which in turn improve the overall predistortion performance. Advisors/Committee Members: G. Tong Zhou (Committee Chair), J. Stevenson Kenney (Committee Member), Jianmin Qu (Committee Member), W. Marshall Leach (Committee Member), Ye (Geoffrey) Li (Committee Member).

Subjects/Keywords: Volterra series; Linearization; Spectral regrowth; Nonlinearity

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APA (6th Edition):

Ding, L. (2004). Digital Predistortion of Power Amplifiers for Wireless Applications. (Doctoral Dissertation). Georgia Tech. Retrieved from http://hdl.handle.net/1853/5184

Chicago Manual of Style (16th Edition):

Ding, Lei. “Digital Predistortion of Power Amplifiers for Wireless Applications.” 2004. Doctoral Dissertation, Georgia Tech. Accessed November 18, 2019. http://hdl.handle.net/1853/5184.

MLA Handbook (7th Edition):

Ding, Lei. “Digital Predistortion of Power Amplifiers for Wireless Applications.” 2004. Web. 18 Nov 2019.

Vancouver:

Ding L. Digital Predistortion of Power Amplifiers for Wireless Applications. [Internet] [Doctoral dissertation]. Georgia Tech; 2004. [cited 2019 Nov 18]. Available from: http://hdl.handle.net/1853/5184.

Council of Science Editors:

Ding L. Digital Predistortion of Power Amplifiers for Wireless Applications. [Doctoral Dissertation]. Georgia Tech; 2004. Available from: http://hdl.handle.net/1853/5184


North Carolina State University

2. Jang, Wonhoon. Modeling Asymmetric Distortion in Multichannel Radio Frequency Communication Systems.

Degree: PhD, Electrical Engineering, 2006, North Carolina State University

A multi-slice behavioral model is used to capture baseband memory effects in multichannel communication circuits and systems. The model is composed of two slices. Each slice includes a static nonlinear function box and linear filters. The first slice captures short-term memory effects and the second slice captures baseband memory effects. A robust extraction procedure for the model is developed with a physically realistic baseband slice. An efficient measurement method for the extraction is used. A 2.4~GHz power amplifier is modeled as an example. The performance of the extracted model is verified by showing that it captures baseband effects when the power amplifier is excited with a two-channel WCDMA signal. One of the advantages of the model is that it can be used in various established simulation schemes such as envelope transient simulation and transient (time-marching or SPICE-like) simulation. The model is shown to be compatible with both. In the transient simulation, the model supports the use of a much lower carrier frequency. This results in enhanced computational efficiency and the same results are achieved. This opens up a new contribution for RF system simulation where complex signals comprise of signals that can be of general form including signals that cannot be represented as modulated carriers. While envelope transient simulation is restricted to slowly modulated carriers, there is no restriction on the type of drive signal so that single tone, multi-tone, CDMA, chirp and noise signals can be combined. Advisors/Committee Members: Michael B. Steer, Committee Chair (advisor), Griff L. Bilbro, Committee Member (advisor), W. Rhett Davis, Committee Member (advisor), Douglas W. Barlage, Committee Member (advisor).

Subjects/Keywords: baseband effects; asymmetric spectral regrowth; RF system; behavioral model; WCDMA

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APA · Chicago · MLA · Vancouver · CSE | Export to Zotero / EndNote / Reference Manager

APA (6th Edition):

Jang, W. (2006). Modeling Asymmetric Distortion in Multichannel Radio Frequency Communication Systems. (Doctoral Dissertation). North Carolina State University. Retrieved from http://www.lib.ncsu.edu/resolver/1840.16/4083

Chicago Manual of Style (16th Edition):

Jang, Wonhoon. “Modeling Asymmetric Distortion in Multichannel Radio Frequency Communication Systems.” 2006. Doctoral Dissertation, North Carolina State University. Accessed November 18, 2019. http://www.lib.ncsu.edu/resolver/1840.16/4083.

MLA Handbook (7th Edition):

Jang, Wonhoon. “Modeling Asymmetric Distortion in Multichannel Radio Frequency Communication Systems.” 2006. Web. 18 Nov 2019.

Vancouver:

Jang W. Modeling Asymmetric Distortion in Multichannel Radio Frequency Communication Systems. [Internet] [Doctoral dissertation]. North Carolina State University; 2006. [cited 2019 Nov 18]. Available from: http://www.lib.ncsu.edu/resolver/1840.16/4083.

Council of Science Editors:

Jang W. Modeling Asymmetric Distortion in Multichannel Radio Frequency Communication Systems. [Doctoral Dissertation]. North Carolina State University; 2006. Available from: http://www.lib.ncsu.edu/resolver/1840.16/4083


North Carolina State University

3. Gharaibeh, Khaled Mohammad. Design Methodology for Multichannel Communication Systems.

Degree: PhD, Electrical Engineering, 2004, North Carolina State University

A methodology for understanding and modeling the interaction of multiple CDMA signals in a nonlinear multichannel environment is introduced and verified. The analysis is based on understanding the statistical properties of input signals and developing a modeling technique that enables distortion to be estimated. This is coupled with the introduction of a new behavioral modeling technique that captures the black box characteristics of multichannel amplifiers. In addition, a performance analysis that relates nonlinear distortion to probability of bit error (BER) is introduced. The analysis presented here provides an insight into communication system design by relating distortion to system performance. The methodology is verified using simulations and measurements performed on a nonlinear power amplifier. A nonlinear model was extracted and used in developing the statistical model by which distortion is estimated. The resulting estimates of distortion were verified using measurements of distortion performed on the amplifier using the IS-95 CDMA system standard. Advisors/Committee Members: Michael B. Steer, Committee Chair (advisor), JEAN-PIERRE FOUQUE, Committee Member (advisor), GIANLUCA LAZZI, Committee Member (advisor), Keith Townsend, Committee Member (advisor).

Subjects/Keywords: Multichannel; Power amplifier; nonlinear system; statitical; autocorrelation function; power spectral density; Volterra series; memoryless; probability of error; Gaussian; random process; code division multiple access; intermodulation; adjacent channel power ration; spectral regrowth.

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APA · Chicago · MLA · Vancouver · CSE | Export to Zotero / EndNote / Reference Manager

APA (6th Edition):

Gharaibeh, K. M. (2004). Design Methodology for Multichannel Communication Systems. (Doctoral Dissertation). North Carolina State University. Retrieved from http://www.lib.ncsu.edu/resolver/1840.16/4810

Chicago Manual of Style (16th Edition):

Gharaibeh, Khaled Mohammad. “Design Methodology for Multichannel Communication Systems.” 2004. Doctoral Dissertation, North Carolina State University. Accessed November 18, 2019. http://www.lib.ncsu.edu/resolver/1840.16/4810.

MLA Handbook (7th Edition):

Gharaibeh, Khaled Mohammad. “Design Methodology for Multichannel Communication Systems.” 2004. Web. 18 Nov 2019.

Vancouver:

Gharaibeh KM. Design Methodology for Multichannel Communication Systems. [Internet] [Doctoral dissertation]. North Carolina State University; 2004. [cited 2019 Nov 18]. Available from: http://www.lib.ncsu.edu/resolver/1840.16/4810.

Council of Science Editors:

Gharaibeh KM. Design Methodology for Multichannel Communication Systems. [Doctoral Dissertation]. North Carolina State University; 2004. Available from: http://www.lib.ncsu.edu/resolver/1840.16/4810

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