@article{MTMT:34720081,
	title = {Analysis of Quantization Noise in Fixed-Point HDFT Algorithms},
	url = {https://m2.mtmt.hu/api/publication/34720081},
	author = {Alrwashdeh, Monther and Czifra, Balazs and Kollár, Zsolt},
	doi = {10.1109/LSP.2024.3372782},
	journal-iso = {IEEE SIGNAL PROC LET},
	journal = {IEEE SIGNAL PROCESSING LETTERS},
	volume = {31},
	unique-id = {34720081},
	issn = {1070-9908},
	abstract = {The Discrete Fourier Transform (DFT) algorithm is widely used in signal processing and communication systems to transform the signal to the frequency-domain. As real-time signal analysis is required for fast processing, several recursive algorithms were proposed to perform the calculation with overlapping sequences in a sliding manner. One Sliding DFT (SDFT) method is the Hopping DFT (HDFT), where the DFT calculations are not evaluated sample-by-sample but with longer steps, thus further reducing the computational complexity compared to the other SDFT algorithms. This letter analyses the effect of fixed-point roundoff error in the HDFT algorithm, including the Updating Vector Transform (UVT) block. A closed-form expression for the resulting quantization noise power at the output of the HDFT algorithm is provided, which is validated through simulations. The results show that the roundoff error can be determined based on the number and size of the hops, the window size, and the number of fractional bits used in the quantization process.},
	year = {2024},
	eissn = {1558-2361},
	pages = {756-760},
	orcid-numbers = {Kollár, Zsolt/0000-0001-6384-265X}
}

@article{MTMT:34846132,
	title = {Learning-based augmentation of physics-based models: an industrial robot use case},
	url = {https://m2.mtmt.hu/api/publication/34846132},
	author = {Retzler, András and Tóth, Roland and Schoukens, Maarten and Beintema, Gerben I. and Weigand, Jonas and Noël, Jean-Philippe and Kollár, Zsolt and Swevers, Jan},
	doi = {10.1017/dce.2024.8},
	journal-iso = {DCE},
	journal = {Data-Centric Engineering},
	volume = {5},
	unique-id = {34846132},
	abstract = {In a Model Predictive Control (MPC) setting, the precise simulation of the behavior of the system over a finite time window is essential. This application-oriented benchmark study focuses on a robot arm that exhibits various nonlinear behaviors. For this arm, we have a physics-based model with approximate parameter values and an open benchmark dataset for system identification. However, the long-term simulation of this model quickly diverges from the actual arm’s measurements, indicating its inaccuracy. We compare the accuracy of black-box and purely physics-based approaches with several physics-informed approaches. These involve different combinations of a neural network’s output with information from the physics-based model or feeding the physics-based model’s information into the neural network. One of the physics-informed model structures can improve accuracy over a fully black-box model.},
	year = {2024},
	eissn = {2632-6736},
	orcid-numbers = {Retzler, András/0000-0001-8635-3146; Kollár, Zsolt/0000-0001-6384-265X}
}

@article{MTMT:33966545,
	title = {Quantization Noise Analysis in FBMC Receivers and its Effect on the BER Performance},
	url = {https://m2.mtmt.hu/api/publication/33966545},
	author = {Alrwashdeh, Monther and Csuka, Barna and Kollár, Zsolt},
	doi = {10.1016/j.dsp.2023.104117},
	journal-iso = {DIGIT SIGNAL PROCESS},
	journal = {DIGITAL SIGNAL PROCESSING},
	volume = {140},
	unique-id = {33966545},
	issn = {1051-2004},
	year = {2023},
	eissn = {1095-4333},
	pages = {1-9},
	orcid-numbers = {Kollár, Zsolt/0000-0001-6384-265X}
}

@article{MTMT:33836101,
	title = {Optimization of the Crest Factor for Complex-Valued Multisine Signals},
	url = {https://m2.mtmt.hu/api/publication/33836101},
	author = {Cseppentő, Bence and Retzler, András and Kollár, Zsolt},
	doi = {10.13164/re.2023.0264},
	journal-iso = {RADIOENGINEERING},
	journal = {RADIOENGINEERING},
	volume = {32},
	unique-id = {33836101},
	issn = {1210-2512},
	year = {2023},
	pages = {264-272},
	orcid-numbers = {Retzler, András/0000-0001-8635-3146; Kollár, Zsolt/0000-0001-6384-265X}
}

@inproceedings{MTMT:34508934,
	title = {Computationally efficient predictive control based on ANN state-space models},
	url = {https://m2.mtmt.hu/api/publication/34508934},
	author = {Hoekstra, J H and Cseppentő, Bence and Beintema, G I and Schouken, M and Kollár, Zsolt and Tóth, Roland},
	booktitle = {2023 62nd IEEE Conference on Decision and Control (CDC)},
	doi = {10.1109/CDC49753.2023.10383724},
	unique-id = {34508934},
	year = {2023},
	pages = {6336-6341},
	orcid-numbers = {Kollár, Zsolt/0000-0001-6384-265X}
}

@CONFERENCE{MTMT:34401007,
	title = {Identifying a simulation model of an industrial robot},
	url = {https://m2.mtmt.hu/api/publication/34401007},
	author = {Retzler, András and Tóth, Roland and Beintema, Gerben Izaak and Noël, Jean-Philippe and Schoukens, Maarten and Weigand, Jonas and Kollár, Zsolt and Swevers, Jan},
	booktitle = {7th Edition of the Workshop on Nonlinear System Identification Benchmarks},
	unique-id = {34401007},
	year = {2023},
	orcid-numbers = {Retzler, András/0000-0001-8635-3146; Kollár, Zsolt/0000-0001-6384-265X}
}

@CONFERENCE{MTMT:34400992,
	title = {Augmented model identification for forward simulation of a robot arm},
	url = {https://m2.mtmt.hu/api/publication/34400992},
	author = {Retzler, András and Tóth, Roland and Swevers, Jan and Noël, Jean-Philippe and Kollár, Zsolt and Beintema, Gerben Izaak and Weigand, Jonas and Maarten, Schoukens},
	booktitle = {Benelux Meeting on Systems and Control 2023},
	unique-id = {34400992},
	year = {2023},
	orcid-numbers = {Retzler, András/0000-0001-8635-3146; Kollár, Zsolt/0000-0001-6384-265X}
}

@article{MTMT:33114821,
	title = {Multicarrier Modulation Schemes for 5G Wireless Access},
	url = {https://m2.mtmt.hu/api/publication/33114821},
	author = {Ahmed, Abu Shakil and Al-Amaireh, Husam and Kollár, Zsolt},
	doi = {10.37936/ecti-cit.2022164.248710},
	journal = {ECTI Transactions on Computer and Information Technology},
	volume = {16},
	unique-id = {33114821},
	abstract = {The 5G wireless access technology will supersede its predecessor, 4G, in the current decade, at first coexisting with it and later as a standalone technology. This work examines and compares the performance of the following orthogonal multicarrier schemes: Cyclic Prefix Orthogonal Frequency Division Multiplexing (CP-OFDM), Windowed Orthogonal Frequency Division Multiplexing (W-OFDM), Filtered Orthogonal Frequency Division Multiplexing (F-OFDM), Universal Filtered Multi-Carrier (UFMC), and Filter Bank Multi-Carrier (FBMC). The system architecture of each scheme is investigated while considering the performance in fading channel models. The simulation was performed using a standard set of parameters, and the performance was appraised based on Power Spectral Density (PSD), Peak to Average Power Ratio (PAPR), Complementary Cumulative Distribution Function (CCDF) of PAPR, Bit Error Rate (BER), and Signal to Noise Ratio (SNR). In addition, a comprehensive analysis is presented concerning filter or window implementation, filtering method, orthogonality, roll-off rate, spectral leakage, spectral efficiency, computational complexity, and runtime complexity. Based on the results, each scheme has its advantages and disadvantages compared with the other methods. FBMC, F-OFDM, and W-OFDM are preferred for better spectrum utilization, transmission accuracy, and power efficiency, respectively. UFMC offers a fine balance between these multicarrier schemes. Therefore, the modulation scheme for the future physical layer will strongly depend on the requirements.},
	year = {2022},
	eissn = {2286-9131},
	pages = {378-392},
	orcid-numbers = {Kollár, Zsolt/0000-0001-6384-265X}
}

@article{MTMT:32925083,
	title = {Low complexity PPN-FBMC Receivers with improved sliding window equalizers},
	url = {https://m2.mtmt.hu/api/publication/32925083},
	author = {Al-Amaireh, Husam and Kollár, Zsolt},
	doi = {10.1016/j.phycom.2022.101795},
	journal-iso = {PHYS COMMUN},
	journal = {PHYSICAL COMMUNICATION},
	volume = {54},
	unique-id = {32925083},
	issn = {1874-4907},
	abstract = {Bandwidth and latency in future 5G and beyond multiple access systems are two extremely important metrics for which the requirements are very strict. Filter Bank Multi-Carrier (FBMC) is a promising scheme that can satisfy many future requirements due to its advantageous spectral characteristics. However, the required computational complexity is one of its major drawbacks. In this paper, we propose two improved receiver structures for the PolyPhase Network (PPN) based FBMC receivers. These improved structures reduce the complexity of the receivers to almost half of the conventional PPN receivers taking advantage of the real valued signal processing. We also investigate the Sliding Window (SW) equalizer technique to enable the implementation of the proposed structures in multipath environments. Furthermore, we propose two modifications to the SW equalization method. First, by using the Hopping Discrete Fourier Transform (HDFT) the complexity requirements can be reduced. Second, by applying overlapped windows the overall system performance in terms of bit error rate can be improved.},
	year = {2022},
	eissn = {1874-4907},
	orcid-numbers = {Kollár, Zsolt/0000-0001-6384-265X}
}

@article{MTMT:33120308,
	title = {Analysis of quantization noise in FBMC transmitters},
	url = {https://m2.mtmt.hu/api/publication/33120308},
	author = {Alrwashdeh, Monther and Kollár, Zsolt},
	doi = {10.1016/j.dsp.2022.103760},
	journal-iso = {DIGIT SIGNAL PROCESS},
	journal = {DIGITAL SIGNAL PROCESSING},
	volume = {131},
	unique-id = {33120308},
	issn = {1051-2004},
	abstract = {This paper investigates Filter Bank MultiCarrier (FBMC) modulation implemented with frequency spreading and polyphase network-based in terms of the introduced quantization noise. As FBMC is considered one of the future candidates for 5G/6G communication systems due to its advantageous spectral properties, the introduced quantization noise in the implementation is an essential design criterion. Analytical expressions for fixed- and floating-point Quantization Noise Power (QNP) in FBMC transmitter schemes are given. Based on the results, it can be stated that the total QNP depends on the number of carriers, overlapping symbols, and the resolution of the quantizer. The results are verified through simulations. Estimating the quantization noise in FBMC systems in the function of the selected bit resolution and keeping it at an acceptable level is an essential design step. The results can be directly employed in the preliminary hardware design of FBMC transmitters, where the choice of the arithmetical units and the bit resolution is a key factor.},
	year = {2022},
	eissn = {1095-4333},
	orcid-numbers = {Kollár, Zsolt/0000-0001-6384-265X}
}