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Alizadeh, M., Händel, P. & Rönnow, D. (2019). Behavioral modeling and digital pre-distortion techniques for RF PAs in a 3 × 3 MIMO system. International journal of microwave and wireless technologies, 11(10), 989-999
Open this publication in new window or tab >>Behavioral modeling and digital pre-distortion techniques for RF PAs in a 3 × 3 MIMO system
2019 (English)In: International journal of microwave and wireless technologies, ISSN 1759-0795, E-ISSN 1759-0787, Vol. 11, no 10, p. 989-999Article in journal (Refereed) Published
Abstract [en]

Modern telecommunications are moving towards (massive) multi-input multi-output systems in 5th generation (5G) technology, increasing the dimensionality of the system dramatically. In this paper, the impairments of radio frequency (RF)power amplifiers (PAs) in a 3x3 MIMO system are compensated in both time and frequency domains. A three-dimensional(3D) time-domain memory polynomial-type model is proposed as an extension of conventional 2D models. Furthermore, a 3D frequency-domain technique is formulated based on the proposed time-domain model to reduce the dimensionality of the model, while preserving the performance in terms of model errors. In the 3D frequency-domain technique, the bandwidth of a system is split into several narrow sub-bands, and the parameters of the system are estimated for each subband. This approach requires less computational complexity, and also the procedure of the parameters estimation for each sub-band can be implemented independently. The device-under-test (DUT) consists of three RF PAs including input and output cross-talk channels. The proposed techniques are evaluated in both behavioural modelling and digital pre-distortion(DPD) perspectives. The results show that the proposed DPD technique can compensate the errors of non-linearity and memory effects by about 23.5 dB and 7 dB in terms of the normalized mean square error and adjacent channel leakage ratio, respectively.

Place, publisher, year, edition, pages
Cambridge University Press, 2019
Keywords
Radio frequency power amplifier, non-linearity, memory effects, multiple-input multiple-output (MIMO), digital pre-distortion.
National Category
Signal Processing
Identifiers
urn:nbn:se:hig:diva-29304 (URN)10.1017/S1759078719000862 (DOI)000500870900001 ()2-s2.0-85067662944 (Scopus ID)
Available from: 2019-01-11 Created: 2019-02-18 Last updated: 2020-03-25Bibliographically approved
Alizadeh, M., Händel, P. & Rönnow, D. (2018). Basis Function Decomposition Approach in Piece-Wise Modeling for RF Power Amplifiers. In: 6th Telecommunications forum TELFOR 2018: . Paper presented at 26th Telecommunications Forum TELFOR 2018, 20-21 November 2018, Belgrade, Serbia. Belgrade: Telecommunications society
Open this publication in new window or tab >>Basis Function Decomposition Approach in Piece-Wise Modeling for RF Power Amplifiers
2018 (English)In: 6th Telecommunications forum TELFOR 2018, Belgrade: Telecommunications society , 2018Conference paper, Published paper (Refereed)
Abstract [en]

In this paper, a new approach is proposed to decompose the basis functions in a piece-wise modeling technique for nonlinear radio frequency (RF) power amplifiers. The proposed technique treats the discontinuity problem of the model output at the joint points between different operating points, whereas preserves the linear and nonlinear properties of the original model within each region. Experimental results show that the proposed technique outperforms the conventional piece-wise model in terms of model errors.

Place, publisher, year, edition, pages
Belgrade: Telecommunications society, 2018
Keywords
Nonlinear dynamic RF power amplifier, behavioral modeling, piece-wise models, digital predistortion.
National Category
Signal Processing
Identifiers
urn:nbn:se:hig:diva-29303 (URN)10.1109/TELFOR.2018.8611865 (DOI)000459714200035 ()2-s2.0-85062060510 (Scopus ID)978-1-5386-7171-9 (ISBN)978-1-5386-7172-6 (ISBN)978-1-5386-7170-2 (ISBN)
Conference
26th Telecommunications Forum TELFOR 2018, 20-21 November 2018, Belgrade, Serbia
Note

Proceedings distributed on CD.

Available from: 2019-01-11 Created: 2019-02-18 Last updated: 2020-03-25Bibliographically approved
Amin, S., Landin, P. N., Händel, P. & Rönnow, D. (2017). 2D Extended envelope memory polynomial model for concurrent dual-band RF transmitters. International journal of microwave and wireless technologies, 9(8), 1619-1627
Open this publication in new window or tab >>2D Extended envelope memory polynomial model for concurrent dual-band RF transmitters
2017 (English)In: International journal of microwave and wireless technologies, ISSN 1759-0795, E-ISSN 1759-0787, Vol. 9, no 8, p. 1619-1627Article in journal (Refereed) Published
Abstract [en]

The paper presents a 2D extended envelope memory polynomial (2D-EEMP) model for concurrent dual-band radio frequency (RF) power amplifiers (PAs). The model is derived based on the physical knowledge of a dual-band RF PA. The derived model contains cross-modulation terms not included in previously published models; these terms are found to be of importance for both behavioral modeling and digital pre-distortion (DPD). The performance of the derived model is evaluated both as the behavioral model and DPD, and the performance is compared with state-of-the-art2D-DPD and dual-band generalized memory polynomial (DB-GMP) models. Experimental result shows that the proposed model resulted in normalized mean square error (NMSE) of -51.7/-51.6dB and adjacent channel error power ratio (ACEPR) of -63.1/-63.4 dB, for channel 1/2, whereas the 2D-DPD resulted in the largest model error and DB-GMP resulted in model parameters that are 3 times more than those resulted with the proposed model with the same performance. As pre-distorter, the proposed model resulted in adjacent channel power ratio (ACPR) of -55.8/ -54.6 dB for channel 1/2 and is 7-10 dB lower than those resulted with the 2D-DPD model and2-4 dB lower compared to the DB-GMP model.

Keywords
Behavioral modeling and digital predistortion of multi-band amplifiers, Power Amplifiers, RF Front-ends
National Category
Signal Processing
Identifiers
urn:nbn:se:hig:diva-23455 (URN)10.1017/S1759078717000277 (DOI)000418998100010 ()2-s2.0-85018373558 (Scopus ID)
Available from: 2016-12-05 Created: 2017-02-02 Last updated: 2018-03-13Bibliographically approved
Khan, Z. A., Händel, P. & Isaksson, M. (2017). A Comparative Analysis of the Complexity/Accuracy Tradeoff in the Mitigation of RF MIMO Transmitter Impairments. In: 2017 89th ARFTG Microwave Measurement Conference (ARFTG): . Paper presented at 89th ARFTG Microwave Measurement Symposium, Advanced Technologies for Communications, 9 June 2017, Honolulu, Hawaii. IEEE, Article ID 8000827.
Open this publication in new window or tab >>A Comparative Analysis of the Complexity/Accuracy Tradeoff in the Mitigation of RF MIMO Transmitter Impairments
2017 (English)In: 2017 89th ARFTG Microwave Measurement Conference (ARFTG), IEEE, 2017, article id 8000827Conference paper, Published paper (Refereed)
Abstract [en]

This paper presents a comparative analysis of the complexity accuracy tradeoff in state-of-the-art RF MIMO transmitter mitigation models. The complexity and accuracy of the candidate models depends on the basis functions considered in these models. Therefore, a brief description of the mitigation models is presented accompanied by derivations of the model complexities in terms of the number of FLOPs. Consequently, the complexity accuracy tradeoff in the candidate models is evaluated for a 2 × 2 RF MIMO transmitter. Furthermore, the model complexities are analyzed for increasing nonlinear orders and number of antennas.

Place, publisher, year, edition, pages
IEEE, 2017
National Category
Signal Processing
Identifiers
urn:nbn:se:hig:diva-24580 (URN)10.1109/ARFTG.2017.8000827 (DOI)000426454300011 ()2-s2.0-85030244336 (Scopus ID)978-1-5386-2747-1 (ISBN)978-1-5386-2748-8 (ISBN)
Conference
89th ARFTG Microwave Measurement Symposium, Advanced Technologies for Communications, 9 June 2017, Honolulu, Hawaii
Available from: 2017-06-27 Created: 2017-06-27 Last updated: 2018-06-26Bibliographically approved
Khan, Z. A., Zenteno, E., Händel, P. & Isaksson, M. (2017). Digital Predistortion for Joint Mitigation of I/Q Imbalance and MIMO Power Amplifier Distortion. IEEE transactions on microwave theory and techniques, 65(1), 322-333, Article ID 7600411.
Open this publication in new window or tab >>Digital Predistortion for Joint Mitigation of I/Q Imbalance and MIMO Power Amplifier Distortion
2017 (English)In: IEEE transactions on microwave theory and techniques, ISSN 0018-9480, E-ISSN 1557-9670, Vol. 65, no 1, p. 322-333, article id 7600411Article in journal (Refereed) Published
Abstract [en]

This paper analyzes the joint effects of in-phase and quadrature (I/Q) imbalance and power amplifier (PA) distortion for RF multiple input multiple output (MIMO) transmitters in the presence of crosstalk. This paper proposes candidate models for the digital predistortion of static I/Q imbalanced sources exciting a dynamic MIMO Volterra system. The proposed models are enhanced using a novel technique based on subsample resolution to account for dynamic I/Q imbalance distortions. Finally, the computational complexity of the proposed models is analyzed for implementation suitability in digital platforms. It is shown that the error spectrum for the proposed models in subsample resolution reaches the noise floor of the measurements. The proposed models achieve a normalized mean squared error of -50 dB and an adjacent channel power ratio of -57 dB for signal bandwidths upto 65 MHz and crosstalk levels ranging to -10 dB. These results demonstrate the effectiveness of the proposed techniques in the joint mitigation of I/Q imbalance and PA distortion with crosstalk for a typical 2x2 MIMO telecommunication setup.

Keywords
Digital predistortion (DPD), in-phase and quadrature (I/Q) imbalance, linearization, multiple input multiple output (MIMO), power amplifier (PA)
National Category
Signal Processing
Identifiers
urn:nbn:se:hig:diva-22675 (URN)10.1109/TMTT.2016.2614933 (DOI)000395460200033 ()2-s2.0-84992060969 (Scopus ID)
Note

© 2016 IEEE. Personal use of this material is permitted. Permission from IEEE must be obtained for all other uses, in any current or future media, including reprinting/republishing this material for advertising or promotional purposes, creating new collective works, for resale or redistribution to servers or lists, or reuse of any copyrighted component of this work in other works.

Available from: 2016-10-28 Created: 2016-10-28 Last updated: 2018-09-21Bibliographically approved
Amin, S., Van Moer, W., Händel, P. & Rönnow, D. (2015). Characterization of concurrent dual-band power amplifiers using a dual two-tone excitation signal. IEEE Transactions on Instrumentation and Measurement, 64(10), 2781-2791, Article ID 7104121.
Open this publication in new window or tab >>Characterization of concurrent dual-band power amplifiers using a dual two-tone excitation signal
2015 (English)In: IEEE Transactions on Instrumentation and Measurement, ISSN 0018-9456, E-ISSN 1557-9662, Vol. 64, no 10, p. 2781-2791, article id 7104121Article in journal (Refereed) Published
Abstract [en]

A method to characterize the memory effects in a nonlinear concurrent dual-band transmitter is presented. It is an extension of the conventional two tone test for power amplifiers to concurrent dual band transmitters. The output signal of a concurrent dual-band transmitter is affected not only by intermodulation products but also by cross-modulation products. In one frequency band, the transmitter is excited by a two tone signal which frequency separation is swept. In the second band the transmitter is concurrently excited by an other two tone signal with slightly wider frequency separation. The frequency difference of the two signals is fixed during the frequency sweep. The two tone test is made at different power levels. The upper and lower third-order inter- and cross-modulation products are measured. The asymmetry between the upper and lower third-order inter- and cross-modulation products are measures of the transmitter's memory effects. The measurement results show that the memory effects are more dominant in the third-order intermodulation products than in the cross modulation products. An error analysis and system calibration was performed and measurement results for two different devices are presented.

Place, publisher, year, edition, pages
IEEE Press, 2015
Keywords
Concurrent dual-band, power amplifier, characterization, linearization, nonlinear distortion, MIMO, DPD
National Category
Signal Processing
Identifiers
urn:nbn:se:hig:diva-18854 (URN)10.1109/TIM.2015.2427731 (DOI)000361487500019 ()2-s2.0-84959505984 (Scopus ID)
Available from: 2014-12-17 Created: 2015-01-27 Last updated: 2018-03-13Bibliographically approved
Alayón Glazunov, A., Prasad, S. & Händel, P. (2014). Experimental Characterization of the Propagation Channel along aVery Large Virtual Array in a Reverberation Chamber. Progress in Electromagnetics Research B, 59, 205-217
Open this publication in new window or tab >>Experimental Characterization of the Propagation Channel along aVery Large Virtual Array in a Reverberation Chamber
2014 (English)In: Progress in Electromagnetics Research B, ISSN 1937-6472, E-ISSN 1937-6472, Vol. 59, p. 205-217Article in journal (Refereed) Published
Abstract [en]

We show that the combined use of radio frequency absorbers and directive antennas can produce significant changes of the radio propagation channel properties along the positions of a virtual array inside a reverberation chamber. A multidimensional characterization of the channel was performed at 40 antenna positions with spacing of 0:233λ at 1 GHz. The average power, the Ricean K-factor, the coherence bandwidth, the r.m.s. delay spread, the mean delay, the beamforming power angle spectrum and array antenna correlation have been studied for different arrangements in the reverberation chamber. The analysis shows that the joint average over time and frequency channel behavior is, as expected, rather homogeneous along the very large array. However, individual realizations of the channel present a pronounced selective behavior in space, time and frequency with parameters varying along the positions of the virtual array suggesting that a heterogeneous behavior of the radio channels can be emulated in reverberation chambers. An important application of the presented study comprises testing of antenna array designs and algorithms in multipath environments. Further development may lead to Over The Air testing of Multiple Input Multiple Output antenna systems of various sizes, i.e., from small to very large arrays.

National Category
Electrical Engineering, Electronic Engineering, Information Engineering
Identifiers
urn:nbn:se:hig:diva-18531 (URN)10.2528/PIERB14031203 (DOI)2-s2.0-84901462104 (Scopus ID)
Available from: 2014-12-12 Created: 2014-12-12 Last updated: 2018-03-13Bibliographically approved
Björsell, N., Händel, P., Jansson, M. & Medawar, S. (2010). Improved Estimate of Parametric Models for Analogue to Digital Converters by Using Weighted Integral Nonlinearity Data. In: Linus Michaeli, Jan Saliga (Ed.), 17th Symposium IMEKO TC4 - Measurement of Electrical Quantities, 15th International Workshop on ADC Modelling and Testing, and 3rd Symposium IMEKO TC19: Environmental Measurements. Paper presented at 17th Symposium IMEKO TC4 - Measurement of Electrical Quantities, 15th International Workshop on ADC Modelling and Testing, and 3rd Symposium IMEKO TC19 - Environmental Measurements,8-10 september, Kosice, Slovakia (pp. 597-600).
Open this publication in new window or tab >>Improved Estimate of Parametric Models for Analogue to Digital Converters by Using Weighted Integral Nonlinearity Data
2010 (English)In: 17th Symposium IMEKO TC4 - Measurement of Electrical Quantities, 15th International Workshop on ADC Modelling and Testing, and 3rd Symposium IMEKO TC19: Environmental Measurements / [ed] Linus Michaeli, Jan Saliga, 2010, p. 597-600Conference paper, Published paper (Refereed)
Abstract [en]

Error modelling has played a major role in generating post-corrections of analogue to digital converters (ADC). Benefits by using parametric models for post-correction are that they requires less memory and that they are easier to identify for arbitrary signals. However, the parameters are estimated in two steps; firstly, the integral nonlinearity (INL) is estimated and secondly, the model parameters. In this paper we propose a method to improve the performance in the second step, by utilizing information about the statistical properties of the first step.

National Category
Electrical Engineering, Electronic Engineering, Information Engineering
Identifiers
urn:nbn:se:hig:diva-7580 (URN)2-s2.0-84872568641 (Scopus ID)978-80-553-0424-3 (ISBN)
Conference
17th Symposium IMEKO TC4 - Measurement of Electrical Quantities, 15th International Workshop on ADC Modelling and Testing, and 3rd Symposium IMEKO TC19 - Environmental Measurements,8-10 september, Kosice, Slovakia
Available from: 2010-09-13 Created: 2010-09-13 Last updated: 2019-12-11Bibliographically approved
Björsell, N., Isaksson, M., Händel, P. & Rönnow, D. (2010). Kautz-Volterra modelling of analogue-to-digital converters. Paper presented at XII International Workshop on ADC Modelling and Testing, September 19–21 2007, Iasi, Romania. Computer Standards & Interfaces, 32(3), 126-129
Open this publication in new window or tab >>Kautz-Volterra modelling of analogue-to-digital converters
2010 (English)In: Computer Standards & Interfaces, ISSN 0920-5489, E-ISSN 1872-7018, Vol. 32, no 3, p. 126-129Article in journal (Refereed) Published
Abstract [en]

In many test and measurement applications, the analogue-to-digital converter (ADC) is the limiting component. Using post-correction methods can improve the performance of the component as well as the over all measurement system. In this paper an ADC is characterised by a Kautz-Volterra (KV) model, which utilises a model-based post-correction of the ADC with general properties and a reasonable number of parameters. It is also shown that the inverse model has the same dynamic properties as the direct KV model. Results that are based on measurements on a high-speed 12-bit ADC, shows good results for a third order model.

Keywords
Kautz-Volterra model, Analogue-to-digital converter, Vector signal analyzers
National Category
Other Electrical Engineering, Electronic Engineering, Information Engineering
Identifiers
urn:nbn:se:hig:diva-1683 (URN)10.1016/j.csi.2009.11.007 (DOI)000275477300008 ()2-s2.0-75849128322 (Scopus ID)
Conference
XII International Workshop on ADC Modelling and Testing, September 19–21 2007, Iasi, Romania
Note

Funding Agency:

- Infineon Technologies Nordic AB

- Knowledge Foundation 

Available from: 2008-05-20 Created: 2008-05-20 Last updated: 2019-12-11Bibliographically approved
Landin, P. N., Isaksson, M. & Händel, P. (2010). Parameter Extraction and Performance Evaluation Method for Increased Performance in RF Power Amplifier Behavioral Modeling. International Journal of RF and Microwave Computer-Aided Engineering, 20(2), 200-208
Open this publication in new window or tab >>Parameter Extraction and Performance Evaluation Method for Increased Performance in RF Power Amplifier Behavioral Modeling
2010 (English)In: International Journal of RF and Microwave Computer-Aided Engineering, ISSN 1096-4290, E-ISSN 1099-047X, Vol. 20, no 2, p. 200-208Article in journal (Refereed) Published
National Category
Other Electrical Engineering, Electronic Engineering, Information Engineering
Identifiers
urn:nbn:se:hig:diva-5832 (URN)10.1002/mmce.20422 (DOI)000275767300009 ()2-s2.0-77649209140 (Scopus ID)
Available from: 2009-11-10 Created: 2009-11-10 Last updated: 2018-03-13Bibliographically approved
Organisations
Identifiers
ORCID iD: ORCID iD iconorcid.org/0000-0002-2718-0262

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