Analysis and design of an adaptive polynomial predistorter with the loop delay estimator

Kim, Dong-Hyun; Lee, Sangseol

doi:10.1002/mop.10391

Cited by 8 publications

(4 citation statements)

References 9 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…We can obtain the LUTs fluctuations in DFBPD expressed as (A6) (please see Appendix A for details). Notice that the result in (A6) is similar to (11) and (12) in Section II. Similarly, the SMF method can also be employed to eliminate the fluctuations in DFBPD, and the results are summarized in Table I.…”

Section: E Performance Of Smoothing Filtersupporting

confidence: 66%

“…The fluctuation in amplitude It is shown that longer loop delay error causes severer LUTs fluctuations. When loop delay error is quite large, which means that and in (11) and (12) are big, the fluctuations would increase sharply. Furthermore, LUTs fluctuations are strongly related to the step size constants and .…”

Section: A Luts Fluctuationsmentioning

confidence: 96%

“…The work in [11] increases the computational complexity by using fast Fourier transform (FFT). The algorithm in [12] requires a high oversampling ratio of 64 to achieve desired accuracy. The technique proposed in [13] gets only a coarse estimation of the loop delay by using a complicated fourth-order cross-correlation.…”

Section: Introductionmentioning

confidence: 99%

See 2 more Smart Citations

On the Robustness of Look-Up Table Digital Predistortion in the Presence of Loop Delay Error

Liu

Lü

Cao

et al. 2012

IEEE Trans. Circuits Syst. I

View full text Add to dashboard Cite

Look-up table (LUT) predistortion is the most promising technique to linearize RF power amplifiers (PAs). Before it can be employed successfully, loop delay errors must be estimated and compensated accurately. In this paper, the effect of loop delay errors on LUT predistortion is analyzed. It is shown that LUTs fluctuations happen to both amplitude and phase tables. Then, a novel loop delay estimation algorithm, with a high degree of robustness and accuracy, is presented. To further improve the robustness of LUT predistortion to loop delay errors, the smoothing filter (SMF) method to polish LUTs fluctuations is proposed here. LUT predistortion can suffer bigger loop delay errors because of the proposed SMF method, but retains good linearization performance close to the optimal one. The performance of the proposed loop delay estimation algorithm is investigated by comparative study with a state-of-the-art algorithm. Its robustness is also demonstrated under a noisy feedback path by simulations. The effectiveness of the SMF method is assessed by both simulations and experiments. Comparison among different predistortion systems is also presented. The results clearly show that the proposed techniques are useful for LUT predistortion.

show abstract

Section: E Performance Of Smoothing Filtersupporting

confidence: 66%

Section: A Luts Fluctuationsmentioning

confidence: 96%

See 1 more Smart Citation

On the Robustness of Look-Up Table Digital Predistortion in the Presence of Loop Delay Error

Liu

Lü

Cao

et al. 2012

IEEE Trans. Circuits Syst. I

View full text Add to dashboard Cite

show abstract

“…But this iteration algorithm was influenced by the PA nonlinear distortion obviously, which disrupted the accuracy and stability of the loop-delay estimation. Kim and Lee adopted 64 times oversampling scheme to improve the estimation accuracy [2]. But it is impractical in wide-band predistorter.…”

Section: Introductionmentioning

confidence: 99%

Direct Learning Predistorter with a New Loop Delay Compensation Algorithm

Kuang

2012

2012 IEEE 75th Vehicular Technology Conference (VTC Spring)

View full text Add to dashboard Cite

Digital baseband predistortion technology can effectively reduce the system nonlinear distortion. However, the predistortion algorithms based on indirect structure are sensitive to measurement noise and the traditional loop-delay estimation algorithms are vulnerable to the amplifier's nonlinear distortion especially in the amplifier saturation region. In this paper, we first present an adaptive nonlinear predistorter based on direct learning structure and then propose a new loop-delay estimation algorithm which applies to PA nonlinear distortion conditions by analyzing the relationship between the system loop-delay misalignment and the amplitude of HPA model identification error output. Simulation results show that the power spectral density (PSD) after the predistortion is very close to that of the ideal signal and a good NMSE performance is achieved.

show abstract

A Fast Digital Predistortion Algorithm for Radio-Frequency Power Amplifier Linearization With Loop Delay Compensation

Kwon

Chen

et al. 2009

IEEE J. Sel. Top. Signal Process.

View full text Add to dashboard Cite

Analysis and design of an adaptive polynomial predistorter with the loop delay estimator

Cited by 8 publications

References 9 publications

On the Robustness of Look-Up Table Digital Predistortion in the Presence of Loop Delay Error

On the Robustness of Look-Up Table Digital Predistortion in the Presence of Loop Delay Error

Direct Learning Predistorter with a New Loop Delay Compensation Algorithm

A Fast Digital Predistortion Algorithm for Radio-Frequency Power Amplifier Linearization With Loop Delay Compensation

Contact Info

Product

Resources

About