| 1. |
- Chani Cahuana, Jessica, 1988, et al.
(författare)
-
Linearization of dual-input Doherty power amplifiers
- 2014
-
Ingår i: International Workshop on Integrated Nonlinear Microwave and Millimetre-Wave Circuits, INMMiC 2014. ; , s. Art. no. 6815085-
-
Konferensbidrag (refereegranskat)abstract
- This paper studies the linearity of dual-input Doherty power amplifiers. We propose a linearization scheme that uses a combination of an efficiency-optimized static splitter and a vector-switched digital predistorter. The performance of the proposed linearization scheme is evaluated on a dual-input Doherty power amplifier operating at 2.0 GHz with 42 dBm peak output power. Experimental results show that the proposed linearization scheme achieves a normalized mean square error of-43.7 dB and an adjacent channel power ratio of-55.8 dBc with a power added efficiency of 42.4%.
|
|
| 2. |
|
|
| 3. |
- Landin, Per, 1983-, et al.
(författare)
-
Proofs of Derivations in Memory Polynomial Baseband Modeling of RF Power Amplifiers
- 2011
-
Rapport (övrigt vetenskapligt/konstnärligt)abstract
- This paper contains supporting derivations for the paperMemory Polynomial Baseband Modeling of RF Power Am-plifiers. All references to numbered equations, propositionsand assumptions are to the corresponding number inMemoryPolynomial Baseband Modeling of RF Power Amplifiers.
|
|
| 4. |
- Amin, S., et al.
(författare)
-
Behavioral Modeling and Linearization of Crosstalk and Memory Effects in RF MIMO Transmitters
- 2014
-
Ingår i: IEEE Transactions on Microwave Theory and Techniques. - : Institute of Electrical and Electronics Engineers (IEEE). - 0018-9480 .- 1557-9670. ; 62:4, s. 810-823
-
Tidskriftsartikel (refereegranskat)abstract
- This paper proposes three novel models for behavioral modeling and digital pre-distortion (DPD) of nonlinear 2 x 2 multiple-input multiple-output (MIMO) transmitters in the presence of crosstalk. The proposed models are extensions of the single-input single-output generalized memory polynomial model. Three types of crosstalk effects were studied and characterized as linear, nonlinear, and nonlinear & linear crosstalk. A comparative study was performed with previously published models for the linearization of crosstalk in a nonlinear 2 x 2 MIMO transmitter. The experiments indicate that, depending on the type of crosstalk, the selection of the correct model in the transmitter is necessary for behavioral modeling and sufficient DPD performance. The effects of coherent and partially noncoherent signal generation on the performance of DPD were also studied. For crosstalk levels of 30 dB, the difference in the normalized mean square error and adjacent channel power ratio was found to be 3-4 dB between coherent and partially noncoherent signal generation.
|
|
| 5. |
- Cao, Wenhui, 1990, et al.
(författare)
-
Complexity Optimized Digital Predistortion Model of RF Power Amplifiers
- 2022
-
Ingår i: IEEE Transactions on Microwave Theory and Techniques. - 0018-9480 .- 1557-9670. ; 70:3, s. 1490-1499
-
Tidskriftsartikel (refereegranskat)abstract
- A novel behavioral modeling technique for digital predistortion of radio frequency power amplifiers (PAs) is proposed. The proposed basis-propagating selection (BAPS) model has an advantage on complexity since its basis functions are constructed as delay or a combination of existing basis functions. The BAPS model effectively optimizes the running time complexity while maintaining the generality of a full Volterra series. A greedy search procedure is applied to select the optimal basis functions. Compared with truncated Volterra models and pruned models obtained by popular pruning techniques, the superior performance of the BAPS model, in terms of accuracy and identification stability, has been fairly justified. The linearization measurements on different types of PAs illustrate that the BAPS model can robustly outperform other models from literature while achieving a low running complexity.
|
|
| 6. |
- Cao, Wenhui, 1990, et al.
(författare)
-
Low-Complexity Digital Predistortion of Concurrent Multiband RF Power Amplifiers
- 2022
-
Ingår i: IEEE Transactions on Microwave Theory and Techniques. - 0018-9480 .- 1557-9670. ; 70:9, s. 4308-4317
-
Tidskriftsartikel (refereegranskat)abstract
- The complexity of digital predistortion (DPD) for the concurrent multiband (MB) power amplifier (PA) has been a bottleneck for 5G wireless communication. A low-complexity MB DPD model has been proposed to reduce the running time complexity of DPD models for concurrent MB scenarios. The proposed MB model can generate the Volterra format basis functions with odd orders, including in-band, cross-band, and intermodulation (IMD) basis terms for arbitrary carrier configurations with an arbitrary number of bands. The optimal basis functions within the band of interests will be selected using a basis-function search algorithm. The lower cost complexity and high model accuracy of the proposed MB model have been validated by the PA linearization experiments in comparison with the memory polynomial MB model.
|
|
| 7. |
|
|
| 8. |
|
|
| 9. |
- Gustavsson, Ulf, 1975, et al.
(författare)
-
On the Impact of Hardware Impairments on Massive MIMO
- 2014
-
Ingår i: IEEE Globecom 2014 Workshop - Massive MIMO: From Theory to Practice, 2014-12-08, Austin, Texas, USA. - 9781479974702 ; , s. 294-300
-
Konferensbidrag (refereegranskat)abstract
- Massive multi-user (MU) multiple-input multiple-output (MIMO) systems are one possible key technology for next generation wireless communication systems. Claims have been made that massive MU-MIMO will increase both the radiated energy efficiency as well as the sum-rate capacity by orders of magnitude, because of the high transmit directivity. However, due to the very large number of transceivers needed at each base-station (BS), a successful implementation of massive MU-MIMO will be contingent on of the availability of very cheap, compact and power-efficient radio and digital-processing hardware. This may in turn impair the quality of the modulated radio frequency (RF) signal due to an increased amount of power-amplifier distortion, phase-noise, and quantization noise. In this paper, we examine the effects of hardware impairments on a massive MU-MIMO single-cell system by means of theory and simulation. The simulations are performed using simplified, well-established statistical hardware impairment models as well as more sophisticated and realistic models based upon measurements and electromagnetic antenna array simulations.
|
|
| 10. |
- Hausmair, Katharina, 1982, et al.
(författare)
-
Digital Predistortion for Multi-Antenna Transmitters Affected by Antenna Crosstalk
- 2018
-
Ingår i: IEEE Transactions on Microwave Theory and Techniques. - 0018-9480 .- 1557-9670. ; 66:3, s. 1524-1535
-
Tidskriftsartikel (refereegranskat)abstract
- In this paper, a digital predistortion (DPD) technique for wideband multi-antenna transmitters is proposed. The proposed DPD compensates for the combined effects of power amplifier (PA) nonlinearity, antenna crosstalk and impedance mismatch. The proposed technique consists of a linear crosstalk and mismatch model block shared by all transmit paths, and a dual-input DPD block in every transmit path. By avoiding the use of multi-input DPD blocks in every transmit path, the complexity of the proposed technique is kept low and scales more favorably with the number of antennas than competing techniques. It is shown that all blocks can be identified from measurements of the PA output signals using least-squares estimation. Measurement results of a four-path transmitter are presented and used to evaluate the proposed DPD technique against existing techniques. The results show that the performance of the proposed DPD technique is similar to those of existing techniques, while the complexity is lower.
|
|
