Статті в журналах: "Digital modulation"

1

Zhang, Hao Chi, Tie Jun Cui, Yu Luo, Jingjing Zhang, Jie Xu, Pei Hang He, and Le Peng Zhang. "Active digital spoof plasmonics." National Science Review 7, no. 2 (October 4, 2019): 261–69. http://dx.doi.org/10.1093/nsr/nwz148.

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Abstract Digital coding and digital modulation are the foundation of modern information science. The combination of digital technology with metamaterials provides a powerful scheme for spatial and temporal controls of electromagnetic waves. Such a technique, however, has thus far been limited to the control of free-space light. Its application to plasmonics to shape subwavelength fields still remains elusive. Here, we report the design and experimental realization of a tunable conformal plasmonic metasurface, which is capable of digitally coding and modulating designer surface plasmons at the deep-subwavelength scale. Based on dynamical switching between two discrete dispersion states in a controlled manner, we achieve digital modulations of both amplitude and phase of surface waves with nearly 100% modulation depth on a single device. Our study not only introduces a new approach for active dispersion engineering, but also constitutes an important step towards the realization of subwavelength integrated plasmonic circuits.

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2

Mankovskyy, Spartаk, Myron Nykolyshyn, and Emiliya Mankovska. "Digital method of SSB modulation." Computational Problems of Electrical Engineering 7, no. 2 (December 14, 2017): 92–96. https://doi.org/10.23939/jcpee2017.02.092.

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This paper is dedicated to modeling of the digital method of single-sideband (SSB) modulation. Digital method of SSB modulation provided in this paper is based on Weaver`s method of SSB modulation. The design and calculations of digital blocks are detailed. Such a model allows obtaining the output SSB signal in time and frequency domains at given input signals and system parameters. This could be useful for design and optimization purposes. In the case of implementation of SSB modulation with the use of analog circuits, it requires mixers, filters constructed with the use of inductors, capacitors, ceramic filters, resonators etc. In the case of the digital implementation of SSB modulation, considered in this paper, no analog filters or multipliers are required. Any filtering and multiplication is performed in digital form. Only analog to digital (ADC) and digital to analog (DAC) converters are required here. The ADC is required for digitizing of input analog signal that is usually in human voice frequency range. The high-speed DAC is used for backward converting of a digital sequence to the analog form of final SSB signal. Such approach allows performing all transformations without any other analog circuits and does not require adjustment in the case of mass-production.

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3

Pamungkas, Wahyu, Anggun Fitrian Isnawati, and Adi Kurniawan. "Modulasi Digital Menggunakan Matlab." JURNAL INFOTEL - Informatika Telekomunikasi Elektronika 4, no. 2 (November 10, 2012): 1. http://dx.doi.org/10.20895/infotel.v4i2.102.

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In telecommunication systems, the determination of the modulation system is an important method in the process of sending information from transmitter to receiver. In the simulation that is done using QPSK modulation system (Quadrature Phase Shift Keying), 8-QAM (Quadrature Amplitude Modulation), 16-QAM (16-Quadrature Amplitude Modulation) that uses AWGN (Additive White Gaussian Noise) channel in the transmission system uses MATLAB software. The execution of the simulation is aimed to describe how the characteristics of the waveform of each block of the modulator, to add noise in the AWGN channel and demodulator. Performance of modulation system testing is used BER (bit error ratio) method. Looking of the faults of comparison bits results of before and after the transmitted bits by using Monte Carlo simulation model. Testing on this simulation using the input data as much as 10.000 data symbols randomly and the level of Eb/No that is various for each modulation used. Performance results BER with the level of Eb / No at 1 dB of the simulated system modulation on the BER values obtained for QPSK 0.0570, 8-QAM at 0.1085 while the 16-QAM at 0.1582 and then the performance of QPSK modulation is the best. If the Eb / No is increased to 8 dB then the becomes BER QPSK smaller modulation is equal to 0.00035, the 8-QAM BER obtained at 0.0076, while the 16-QAM modulation to be 0.0139

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4

Rong, Li. "Automatic Recognition of M-Nary Digital Modulation Signals." Applied Mechanics and Materials 336-338 (July 2013): 1665–69. http://dx.doi.org/10.4028/www.scientific.net/amm.336-338.1665.

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For the using of multi-modulation, the precondition of receiving and demodulating signal is to decide the type of the modulation. So automatic recognition of modulation signal has significant influences on the analysis of communication signals. In this paper, nine types of M-nary digital modulations are recognized by using four effective key features and utilizing the decision-theoretic approachThe simulation results shows that overall success rate is over 99% at SNR4dBThis algorithm is verified its good performance. It has simple structure, less calculation and good performance of real time. It can realize automatic modulation recognition.

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5

Md., Juwel Sheikh. "VIDEO TRANSMISSION IN V-BLAST ENCODED MIMO MC-CDMA WIRELESS SYSTEM: PERFORMANCE STUDY." International Journal of Ambient Systems and applications(IJASA) 8, no. 1/2 (July 12, 2023): 19. https://doi.org/10.5281/zenodo.8139137.

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In this paper, the bit error rate (BER) performance study on video transmission in a V-BLAST encoded 2×2 MIMO MC-CDMA wireless communication system has been made. The system deploys two channel encoding schemes (1/2-rated Convolution and CRC) under four digital modulations (BPSK, DPSK, QPSK and QAM) and zero forcing (ZF) channel detection method. It is apparent that the BPSK modulation outperforms as compared to DPSK, QPSK and QAM modulation schemes in V-BLAST based MIMO MCCDMA communication system under AWGN channel. The 16QAM digital modulation shows worst performance in video transmission as compared to other low order digital modulations. It is obvious from the present MATLAB based simulation study that the V-BLAST encoded 2×2 MIMO MC-CDMA wireless system with the deployment of ZF signal detection and ½-rated Convolution and CRC channel coding schemes shows superior performance using BPSK digital modulation in video transmission.

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6

Mohammed, Raya Kahtan, and Hamsa Abdulkareem Abdullah. "Implementation of digital and analog modulation systems using FPGA." Indonesian Journal of Electrical Engineering and Computer Science 18, no. 1 (April 1, 2020): 485. http://dx.doi.org/10.11591/ijeecs.v18.i1.pp485-493.

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<p><span>FPGA (Field Programmable Gate Array) based implementations of digital and analog modulation techniques play a vital rule in the design of signal processing system. The performance and flexibility provided by reconfigurable computing speeds up the development process in signal processing implementations using FPGA. Different methods for digital and analog modulation are designed in this paper by usinSg System Generator tools &amp; Vivado. Then all designed systems are implemented successfully in an FPGA hardware via the NEXYS 4 DDR with ARTIX 7 XC7A100T. A comparison between five types of digital modulation techniques is discussed in terms of resources utilization in FPGA hardware. And also, the implementation of analog modulations in FPGA is contributed in this work. The hardware implementation shows that the number of slice LUTs in ASK modulation is 0.07% while in FSK modulation is 0.13% of the total number of slice LUTs. And also, the number of bounded IO that used for PSK modulation is 4.8% while in PM modulation is 61.4% of the total number bounded IO.</span></p>

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7

Raya., K. Mohammed, and A. Abdullah Hamsa. "Implementation of digital and analog modulation systems using FPGA." Indonesian Journal of Electrical Engineering and Computer Science (IJEECS) 18, no. 1 (April 1, 2020): 485–93. https://doi.org/10.11591/ijeecs.v18.i1.pp485-493.

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FPGA (Field Programmable Gate Array) based implementations of digital and analog modulation techniques play a vital rule in the design of signal processing system. The performance and flexibility provided by reconfigurable computing speeds up the development process in signal processing implementations using FPGA. Different methods for digital and analog modulation are designed in this paper by usinSg System Generator tools & Vivado. Then all designed systems are implemented successfully in an FPGA hardware via the NEXYS 4 DDR with ARTIX 7 XC7A100T. A comparison between five types of digital modulation techniques is discussed in terms of resources utilization in FPGA hardware. And also, the implementation of analog modulations in FPGA is contributed in this work. The hardware implementation shows that the number of slice LUTs in ASK modulation is 0.07% while in FSK modulation is 0.13% of the total number of slice LUTs. And also, the number of bounded IO that used for PSK modulation is 4.8% while in PM modulation is 61.4% of the total number bounded IO.

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8

Muñoz-Ramírez, Mauricio, Hugo Valderrama-Blavi, Marco Rivera, and Carlos Restrepo. "An Approach to Natural Sampling Using a Digital Sampling Technique for SPWM Multilevel Inverter Modulation." Energies 12, no. 15 (July 30, 2019): 2925. http://dx.doi.org/10.3390/en12152925.

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This paper introduces an approach that applies a digital sampling technique for a sinusoidal pulse width modulation (SPWM) multilevel inverter modulation that reduces the total harmonic contents in the output voltage compared to that of classical regular sampling techniques. This new modulation emulates with a high degree of fidelity a natural sampling pulse width modulation (PWM). The theoretical analysis of this new digital technique compared with natural sampling has been validated by simulations and through experiments with a built prototype that performed five–level inverter modulations with vertically displaced carriers in phase disposition. Both simulation and experimental results generate a SPWM output voltage with higher fidelity than classic regular sampling techniques, allowing a reduction of the filtering demands on the inverter output, which in turn can decrease the converter size and its manufacturing costs. As the presented technique is digital, the resulting modulation is more robust against switching noise, jitter, and other system perturbations and the modulation parameters can be changed easily, even in an automated way. For this reason, the modulation introduced here can be a useful tool to perform spectral analysis for different multilevel modulations and systems.

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9

Volkov, A. A., V. A. Kuzyukov, and M. S. Morozov. "MODEM OPTIONS FOR DIGITAL RADIO COMMUNICATION SYSTEMS." World of Transport and Transportation 15, no. 6 (December 28, 2017): 48–56. http://dx.doi.org/10.30932/1992-3252-2017-15-6-4.

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[For the English abstract and full text of the article please see the attached PDF-File (English version follows Russian version)].ABSTRACT New versions of the modulator and demodulator (modem) for the digital railway radio communication system GSM-R have been developed, which increase the noise immunity twofold. To realize «cos» and «sin» blocks, a phase modulator is used, two coherent quadrature demodulators are connected to its output in parallel. It is shown that «cos» block generates the signal cos [msinφ(t)], which is transferred to the operating frequency of the transmitter by means of subsequent blocks representing the structure of the one-side amplitude modulation driver, forming the final phase-modulated signal. It is proposed to detect an FM signal not from the modulation envelope, as it is done customary, but coherently, which excludes the quadrature component of the interference. Keywords: railway, radio communication, digital signal, Gaussian filter, modulation, coherent FM signal detector, noise immunity, frequency efficiency.

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10

Luţă, Alexandru-Daniel, and Paul Bechet. "An Algorithm for Automatic Recogniton of Digital QAM Modulations." International conference KNOWLEDGE-BASED ORGANIZATION 25, no. 3 (June 1, 2019): 36–41. http://dx.doi.org/10.2478/kbo-2019-0114.

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Abstract This paper proposes a new Matlab-developed algorithm for automatic recognition of digital modulations using the constellation of states. Using this technique the automatic distinction between four digital modulation schemes (8-QAM, 16-QAM, 32-QAM and 64-QAM) was made. It has been seen that the efficiency of the algorithm is influenced by the type of modulation, the value of the signal-to-noise ratio and the number of samples. In the case of an AWGN noise channel the simulation results indicated that the value of SNR (signal-to-noise ratio) has a small influence on the recognition rate for lower-order QAM (8-QAM and 16-QAM). The length of the signal may change essentially the recognition rate of this algorithm especially for modulations with a high number of bits per symbol. Consequently, for the 64-QAM modulation in a case of 25dB signal-to-noise ratio the recognition rate is doubled if the sample rate is incresed from 5400 to 80640.

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11

Awan, Waseem. "Digital Modulator using Digitally Programmable Complementary metal–oxide–semiconductor Differential Voltage Current Conveyor." Academic Journal of Research and Scientific Publishing 6, no. 65 (September 5, 2024): 21–40. http://dx.doi.org/10.52132/ajrsp.e.2024.65.2.

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This study aims to Developing a digital modulation system using a new technology and idea, which is the digitally programmable CMOS (Complementary metal–oxide–semiconductor), Integrate the CMOS DVCC circuit as a modulator in the communication systems, as will be explained in chapter 3, Finally, simulate this new idea in communication by using a simulation program, which is PSpice software, and analyzing the results. By focusing on How to use digital programmable CMOS (Complementary Metal–Oxide–Semiconductor) in a communication system as a digital modulator, Verifying the effectiveness of the study using simulation software such as PSpice and MATLAB, and Analyzing and verifying the effectiveness of the three modified modulation techniques. Digitally programmable Binary Amplitude shift keying (DP BASK), Digitally programmable Binary Phase shift keying (DP BPSK), And Digitally programmable Binary Frequency shift keying (DP BFSK). This study adopts an applied research approach. The study demonstrated that the CMOS DVCC circuit could be successfully integrated into communication systems as a digital modulator. The study recommended to conduct further research on the noise resistance capabilities of the DP modulation techniques, and explore additional modulation techniques that could benefit from digitally programmable CMOS technology, such as Quadrature Amplitude Modulation (QAM) or Orthogonal Frequency-Division Multiplexing (OFDM).

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12

Prakasam, P., and M. Madheswaran. "Digital Modulation Identification Model Using Wavelet Transform and Statistical Parameters." Journal of Computer Systems, Networks, and Communications 2008 (2008): 1–8. http://dx.doi.org/10.1155/2008/175236.

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A generalized modulation identification scheme is developed and presented. With the help of this scheme, the automatic modulation classification and recognition of wireless communication signals with a priori unknown parameters are possible effectively. The special features of the procedure are the possibility to adapt it dynamically to nearly all modulation types, and the capability to identify. The developed scheme based on wavelet transform and statistical parameters has been used to identify M-ary PSK, M-ary QAM, GMSK, and M-ary FSK modulations. The simulated results show that the correct modulation identification is possible to a lower bound of 5 dB. The identification percentage has been analyzed based on the confusion matrix. When SNR is above 5 dB, the probability of detection of the proposed system is more than 0.968. The performance of the proposed scheme has been compared with existing methods and found it will identify all digital modulation schemes with low SNR.

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13

Shetty, Mamtha. "Design of BPSK Modulator Using VHDL." INTERNATIONAL JOURNAL OF COMPUTERS & TECHNOLOGY 13, no. 12 (October 23, 2014): 5247–52. http://dx.doi.org/10.24297/ijct.v13i12.5276.

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Binary Phase Shift Keying represents the simulation results of binary digital modulation schemes. Here for BASK and BPSK modulation techniques use FPGA algorithm. If multiplier block is used for multiplication bit stream with carrier signal, used time will rises. In addition using multiplier block obtained simulation results were analyzed and compared to other simulation results. Source consumptions of FPGA-based BASK modulation technique and BPSK modulation technique were compared. Also, for different modulation algorithm, source consumptions of BASK and BPSK modulation technique were analyzed using VHDL. Designed modulators using VHSIC (Very High Speed Integrated Circuit) Hardware Description Language (VHDL) was realized on high speed FPGA (Field Program Programmable Gate Array). Because for used modulation technique data rate transfer is fairly important in wireless communication systems. The highest speed data rate transfer can be realized using fiber optic cables. In addition, BER (Bit Error Rate) of BASK and BPSK modulator was compared using MATLAB simulation program. Binary data rate is same for BPSK and BASK. BPSK and BASK modulations were designed on FPGA using VHDL hardware description language.

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14

Joo, Kyung-II, Sungjin Lim, Ki-Dong Lim, Jin Su Lee, Min-Kyu Park, Seon Kyu Yoon, and Kwang-Hoon Lee. "P‐89: Digital Holography Microscope with liquid crystal phase modulator." SID Symposium Digest of Technical Papers 54, no. 1 (June 2023): 1388–90. http://dx.doi.org/10.1002/sdtp.16843.

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We proposed a DHM system with improved resolution property by using liquid crystal (LC) phase modulator. The LC phase modulator can stably control the phase modulation characteristics of the interference pattern and implements the four‐step phase shifting scheme. The proposed DHM system showed a four‐fold improvement in resolution compared to the conventional DHM with polarized camera. Finally, it was confirmed that the modulation transfer function (MTF) value was improved 2 times at the resolution target of 105 lines/mm.

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15

Ahmed, Md Firoz, Md Tahidul Islam, and Abu Zafor Md. Touhidul Islam. "Performance of Convolution and CRC Channel Encoded V-Blast 4x4 MIMO MC-CDMA Wireless Communication System." International Journal of Ambient Systems and Applications 9, no. 2 (June 30, 2021): 1–6. http://dx.doi.org/10.5121/ijasa.2021.9201.

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Wireless communications are among the rapidly growing fields in our current life and have a massive effect on every aspect of our everyday life. In this paper, the performance of the various digital modulation techniques (BPSK, DPSK, QPSK, and QAM) based wireless communication system on the audio signal transmission through the additive Gaussian Noise (AWGN) channel is assessed on the basis of bit error rate (BER) as a function of the signal-to-noise ratio (SNR). Based on the results of this study, BPSK modulation outperforms the DPSK, QPSK, and QAM modulation strategies in the MIMO MC-CDMA VBlast based wireless communication system. The digital modulation of QPSK shows the worst performance in audio signal transmission especially in comparison to other digital modulations. It is clear from the current simulation study based on MATLAB that the V-Blast encoded 4×4 MIMO MC-CDMA wireless system with minimum mean square error (MMSE) signal detection and 1⁄2-rated convolution and cyclic redundancy check (CRC) channel encoding strategies show good performance utilizing BPSK digital modulation in audio signal transmission.

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16

Md., Firoz Ahmed1. "PERFORMANCE OF CONVOLUTION AND CRC CHANNEL ENCODED V-BLAST 4×4 MIMO MCCDMA WIRELESS COMMUNICATION SYSTEM." International Journal of Ambient Systems and applications(IJASA) 09, no. 1/2 (April 8, 2023): 6. https://doi.org/10.5281/zenodo.7802232.

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Wireless communications are among the rapidly growing fields in our current life and have a massive effect on every aspect of our everyday life. In this paper, the performance of the various digital modulation techniques (BPSK, DPSK, QPSK, and QAM) based wireless communication system on the audio signal transmission through the additive Gaussian Noise (AWGN) channel is assessed on the basis of bit error rate (BER) as a function of the signal-to-noise ratio (SNR). Based on the results of this study, BPSK modulation outperforms the DPSK, QPSK, and QAM modulation strategies in the MIMO MC-CDMA VBlast based wireless communication system. The digital modulation of QPSK shows the worst performance in audio signal transmission especially in comparison to other digital modulations. It is clear from the current simulation study based on MATLAB that the V-Blast encoded 4×4 MIMO MC-CDMA wireless system with minimum mean square error (MMSE) signal detection and 1&frasl;2-rated convolution and cyclic redundancy check (CRC) channel encoding strategies show good performance utilizing BPSK digital modulation in audio signal transmission.

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17

Kudinova, T. V., G. A. Osipov, and F. A. Nanay. "Digital demodulators for analog signals: comparative analysis and simulation." Journal of Physics: Conference Series 2094, no. 2 (November 1, 2021): 022048. http://dx.doi.org/10.1088/1742-6596/2094/2/022048.

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Abstract The paper examines digital demodulators for two commonly used techniques of modulating analog signals: amplitude modulation (AM) and frequency modulation (FM). The described demodulators can be used to perform the radio monitoring of narrowband signal ranges including FM broadcasting stations as well as license-free CB, LPD, PMR bands. The demodulators considered in this work are intended for programmable devices with limited memory and computing resources, for example, for STM32F407 microcontrollers and similar ones. The paper presents the analysis and simulation of demodulators for AM signals, FM signals with low modulation indices and for FM signals without restriction on the modulation indices. In addition, the authors demonstrate how to demodulate the phase-modulation signal using a quadrature demodulator. The number of operations that are available for demodulation is limited by IF multiplication and filtering. The simulation of the analyzed demodulation algorithms was carried out in the Scilab environment which is a free analogue of the Matlab environment. To explain the principle of operation of demodulators, block diagrams and graphs of signals in time and frequency domains are shown.

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18

Sundareshan, B. "Digital Modulation—Baseband Techniques." IETE Journal of Education 33, no. 1 (January 1992): 35–44. http://dx.doi.org/10.1080/09747338.1992.11436355.

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19

Bhatnagar, R. C., and B. Sundareshan. "Digital Modulation—Bandpass Techniques." IETE Journal of Education 33, no. 1 (January 1992): 45–56. http://dx.doi.org/10.1080/09747338.1992.11436356.

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20

Rogers, Steve. "Digital modulation and coding." Control Engineering Practice 5, no. 4 (April 1997): 585. http://dx.doi.org/10.1016/s0967-0661(97)83768-9.

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21

Wang, Xiang Zhong, Jun Jie Zhu, Xu Feng, and Cheng Chen. "High Accuracy Multi-Channel SPWM Generator Based on Digital Natural Sampling." Advanced Materials Research 433-440 (January 2012): 7430–35. http://dx.doi.org/10.4028/www.scientific.net/amr.433-440.7430.

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Principle of triangle carrier amplitude modulation is equivalent with sinusoidal modulator amplitude modulation, and principle of sinusoidal modulator phase-shifting is equivalent with the triangle carrier phase-shifting are proposed. A digital natural sampling based on multi-channel SPWM generator is developed using time-division multiplexed access (TDMA). Flip time computation by CPU is no needed in the generator which has an accuracy flip time. Design principle and implementation based on FPGA are introduced, and testing results are presented.

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22

Muhammad, A. B., Denny Darlis, and Arfianto Fahmi. "Design and Realization of Digital Modulator BPSK, QPSK and 16-QAM on FPGA." Journal of Measurements, Electronics, Communications, and Systems 2, no. 1 (December 31, 2016): 1. http://dx.doi.org/10.25124/jmecs.v2i1.1482.

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Innovations in the field of wireless communication are growing very rapidly in line with the behavior of modern societies that have high mobility, need of the flexible services, easy access, and high speed data transfer to facilitate any activities of its users. The needs of every user of any variety are more than just voice, video, data transfer, up to a demanding streaming multimedia capabilities and reliability of the communication system used. One of the factors that affect the quality and speed of data transfer in wireless communications is modulation. The development of technological modulation allows data transfer rate to become faster, more resistant to noise, and have high security (encryption) in order to secure data sent over the lead. The implementation of digital modulator PSK (Phase Shift Keying Modulation) and QAM (Quadrature Amplitude Modulation) on FPGA is designed to simplify the design of a hardware by representing the input which is prepared by using the VHDL programming language. The input will be programmed by logic gates contained in the FPGA into a circuit that functions as a digital modulator. This device can map the input bits into a modulator output that has been mapped in accordance with the coordinates of the constellation. The expected results of the implementation are three types of digital modulator, namely: BPSK, QPSK and 16-QAM to be implemented on FPGA Xilinx Spartan-6 XC6SLX45 CSG324C; modulation type to be used can be selected by entering input on the programs implemented in the FPGA. In the design used input from laptop devices with UART interface and data types for input is ASCII 8 bit for later analysis simulation results modulation of the input to each modulator using Modelsim for simulation design and Chipscope for simulation system design implemented in the FPGA.

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23

Kushnirenko, N. I., and V. Ya Chechelnytskyi. "Digital modulation method based on perfect binary arrays." Odes’kyi Politechnichnyi Universytet. Pratsi, no. 1 (June 10, 2014): 218–24. http://dx.doi.org/10.15276/opu.1.43.2014.37.

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24

Horbatyi, I. V., U. S. Carp, and I. R. Tsymbaliuk. "Modulator for implementation of amplitude modulation of many components." Технология и конструирование в электронной аппаратуре, no. 3-4 (2021): 30–35. http://dx.doi.org/10.15222/tkea2021.3-4.30.

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The authors consider various anti-noise techniques in systems using digital signals, in particular QAM (quadrature amplitude modulation) signals. To increase the noise immunity of a system, it is proposed to use amplitude modulation of many components (AMMС). The advantages of this approach are demonstrated. The principles of AMMС signal formation are explained. The frequency efficiency, energy efficiency, and information efficiency of such signals are theoretically calculated. Different types of digital modulation are compared, the data being presented as a table, and a conclusion is made about a possible practical implementation of the modulator for AMMC signal formation. Structural and functional diagrams of the modulator for AMMC implementation are proposed. The study formulates basic operating principles of such a device, which are used to propose a design option of the modulator. The paper describes particular aspects of creating the main units of the modulator. The authors investigate the characteristics of such a device, particularly the spectrum of the output signal. The obtained research results allow drawing a conclusion that the device complies with the formulated implementation principles of the declared modulation type. A general conclusion is made that the manufactured modulator is suitable for the AMMC. The device is proposed to be used in modern digital communication systems, such as mobile communication systems.

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25

Zhu, Hong Li, та Xia Sun. "Design and Realization of π／4-DQPSK Modulation Circuit Based on FPGA". Advanced Materials Research 490-495 (березень 2012): 402–6. http://dx.doi.org/10.4028/www.scientific.net/amr.490-495.402.

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Technology of digital modulation plays an important role in digital communication system, the combination of digital communication technology and FPGA is a certain trend. This paper designs and realizes a new π／4-DQPSK modulator based on FPGA. The simulation result provides the correction of the design. With simple solution, high integration and high reliability, this π／4-DQPSK modulator can be widely used in digital communication field.

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26

Ireeta, Winston Tumps, Esther Nabadda, and George Isoe. "Digital high-speed data modulation techniques." Engineering and Applied Science Letters 4, no. 4 (December 30, 2021): 1–4. http://dx.doi.org/10.30538/psrp-easl2021.0075.

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Most radio stations use frequency modulation (FM) to broadcast yet amplitude modulation (AM) ensures long distance modulation. The limitations of FM reception are the line of sight and the area of reception. These two parameters are much smaller in FM compared to AM which makes AM modulation have an added advantage over FM modulation. The results presented in this paper include; direct modulation at different bias currents and different transmission fiber lengths and the amplitude modulation using the Mach-Zehnder. The results show the possibility to transmit huge data at high speeds to over 100Gbps.

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27

Jader, Rasool F., Mudhafar Haji M. Abd, and Ihsan Hamza Jumaa. "Signal Modulation Recognition System Based on Different Signal Noise Rate Using Artificial Intelligent Approach." Journal of Studies in Science and Engineering 2, no. 4 (December 30, 2022): 37–49. http://dx.doi.org/10.53898/josse2022244.

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Everyone has paid much attention to modulation-type recognition in the past few years. There are many ways to find the modulation type, but only a few good ways to deal with signals with a lot of noise. This study comes up with a way to test how well different machine learning algorithms can handle noise when detecting digital and analogue modulations. This study looks at the four most common digital and analogue modulations: Phase Shift Keying, Quadrature Phase Shift Keying, Amplitude Modulation, and Morse Code. A signal noise rate from -10dB to +25dB is used to find these modulations. We used machine learning algorithms to determine the modulation type like Decision Tree, Random Forest, Support Vectors Machine, and k-nearest neighbours. After the IQ samples had been converted to the amplitude of samples and radio frequency format, the accuracy of each method looked good. Still, in the format of the sample phase, each algorithm's accuracy was less. The results show that the proposed method works to find the signals that have noises. When there is less noise, the random forest algorithm gives better results than SVM, but SVM gives better results when there is more noise.

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28

Liu, Xiaoli, Pau Closas, M. Liang, Y. Morton, T. Zhang, and Z. Hong. "Performance evaluation of MSK and OFDM modulations for future GNSS signals." GPS Solutions 18, no. 2 (April 1, 2014): 163–75. https://doi.org/10.1007/s10291-014-0368-6.

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The objective of this work is to investigate the performances of orthogonal frequency division multiplexing (OFDM) and minimum frequency shift keying (MSK) modulations as potential future global navigation satellite systems (GNSS) signal modulation schemes. MSK is used in global system for mobile communications because of its spectral efficiency, while OFDM is used in WLAN and digital video broadcast-terrestrial because of its multipath mitigation capability. These advantages of MSK and OFDM modulations render them as promising modulation candidates for future GNSS signals to offer enhanced performances in challenging environments. Gabor bandwidth and multipath error envelopes of these two modulations were computed and compared with those of the current global positioning system (GPS), Galileo, and Beidou signal modulations. The results show that OFDM modulation demonstrated promises as a viable future GNSS modulation, especially for signals that require pre-filtering bandwidths larger than 2 MHz, while MSK modulation is more desirable for pre-filtering bandwidth below 2 MHz where it exhibits the largest Gabor bandwidth.

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29

Prathap, Dr Joseph Anthony, Maruthi Pottella, Srikanth Thammisetti, and Sainath Rachakonda. "FPGA based Design of Triple Modular Redundancy for Hybrid Digital Pulse Width Modulation Generator." Revista Gestão Inovação e Tecnologias 11, no. 2 (June 30, 2021): 2249–59. http://dx.doi.org/10.47059/revistageintec.v11i2.1885.

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This paper proposes the Triple Modular Redundancy checker for the Hybrid Digital Pulse Width Modulation generator to verify the correctness in the output signal. The proposed design involves replicating the Hybrid Digital Pulse Width Modulation Generator thrice and the majority voter circuit validates the correct output by considering the two accurate signals out of the three outputs. The digital pulse width modulation generator is broadly classified as Counter-based Digital Pulse Width Modulation, Delay line-based Digital Pulse Width Modulation, and Hybrid-based Digital Pulse Width Modulation. Among the three methods, the Hybrid based Digital Pulse Width Modulation is preferred as the Counter-based Digital Pulse Width Modulation uses high clocking frequency and the Delay line-based Digital Pulse Width Modulation occupies a large area. The proposed Triple Modular Redundancy is implemented using the FPGA and parameters such as power analysis and device utilization chart.

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30

Nidhi, Nitin, Pin-En Su, and Sudhakar Pamarti. "Open-Loop Wide-Bandwidth Phase Modulation Techniques." Journal of Electrical and Computer Engineering 2011 (2011): 1–12. http://dx.doi.org/10.1155/2011/507381.

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The ever-increasing growth in the bandwidth of wireless communication channels requires the transmitter to be wide-bandwidth and power-efficient. Polar and outphasing transmitter topologies are two promising candidates for such applications, in future. Both these architectures require a wide-bandwidth phase modulator. Open-loop phase modulation presents a viable solution for achieving wide-bandwidth operation. An overview of prior art and recent approaches for phase modulation is presented in this paper. Phase quantization noise cancellation was recently introduced to lower the out-of-band noise in a digital phase modulator. A detailed analysis on the impact of timing and quantization of the cancellation signal is presented. Noise generated by the transmitter in the receive band frequency poses another challenge for wide-bandwidth transmitter design. Addition of a noise transfer function notch, in a digital phase modulator, to reduce the noise in the receive band during phase modulation is described in this paper.

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31

Nugroho, Prapto. "Design of a 20 Mbps OQPSK Modulator Based on Multiplexers." JURNAL INFOTEL 16, no. 4 (December 27, 2024): 855–70. https://doi.org/10.20895/infotel.v16i4.1237.

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This paper aims to delve into the design and implementation aspects of an OQPSK (Offset Quadrature Phase Shift Keying) modulator within the context of modem technology, underscoring its pivotal role in contemporary information technology infrastructure. The research primarily focuses on elucidating the theoretical foundations of OQPSK modulation, which represents an enhancement of QPSK modulation techniques. Central to the design is the utilization of a multiplexer to select one carrier signal out of four, which is subsequently modulated by data bits. Furthermore, the modulator employs two square wave signals phased 90 degrees apart, which are transformed into differential sinusoidal signals to constitute the carrier signal. Operating frequencies encompass a 5 MHz streaming data bits frequency and a 10 MHz clock frequency. Simulation results validate the efficacy of the OQPSK modulator by demonstrating its capability to generate modulated signals at a robust data transfer rate of 20 Mbps. This underscores the modulator's effectiveness in transmitting digital data over analog communication channels. In conclusion, the designed OQPSK modulator exemplifies its proficiency in efficiently modulating and demodulating signals, thereby bolstering connectivity and communication across diverse societal sectors. This research contributes significantly to the advancement of modem technology, which is indispensable for the expansion and maintenance of modern communication networks, ensuring robust connectivity in the digital age.

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32

N, Sharan, Suma V. Shetty, and Dr H. C. Sateesh Kumar. "Digital Modulation in Modern Communication Systems." INTERANTIONAL JOURNAL OF SCIENTIFIC RESEARCH IN ENGINEERING AND MANAGEMENT 09, no. 04 (April 4, 2025): 1–9. https://doi.org/10.55041/ijsrem43721.

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Digital modulation is a fundamental technology in modern communication systems, enabling efficient and reliable data transmission over wired and wireless networks. Compared to analog modulation, digital techniques such as Phase Shift Keying (PSK), Quadrature Amplitude Modulation (QAM), and Orthogonal Frequency Division Multiplexing (OFDM) offer higher data rates, superior noise immunity, and better spectral efficiency. These advantages make digital modulation essential for applications in mobile communication, satellite systems, and the Internet of Things (IoT). Additionally, digital modulation supports advanced error correction, encryption, and digital signal processing (DSP), ensuring robust and secure communication. This paper explores the principles, advantages, and applications of digital modulation, emphasizing its critical role in modern communication technologies such as 4G, 5G, and beyond. Keywords: Digital Modulation, PSK, QAM, OFDM, Noise Immunity, Spectral Efficiency, 5G, IoT, DSP, Wireless Communication

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33

Kunisa, A., S. Takahashi, and N. Itoh. "Digital modulation method for recordable digital video disc." IEEE Transactions on Consumer Electronics 42, no. 3 (1996): 820–25. http://dx.doi.org/10.1109/30.536191.

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34

Katoh, Hisakazu, Tomohiro Saitoh, Masaru Takechi, and Hajime Matsumura. "A Digital Modulation Scheme for Digital Satellite Broadcasting." Journal of the Institute of Television Engineers of Japan 47, no. 10 (1993): 1358–66. http://dx.doi.org/10.3169/itej1978.47.1358.

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35

Vijaya, C. "Digital Modulation & Detection Techniques Using FRFT Basis Functions." Bonfring International Journal of Research in Communication Engineering 6, Special Issue (November 30, 2016): 44–47. http://dx.doi.org/10.9756/bijrce.8198.

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36

Gohokar, V. V. "Simulation of Digital Modulation Techniques." IETE Journal of Education 53, no. 1 (January 2012): 5–8. http://dx.doi.org/10.1080/09747338.2012.10876089.

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37

Bobinsky, E. "Digital modulation techniques [Book Review]." IEEE Communications Magazine 39, no. 6 (June 2001): 24–28. http://dx.doi.org/10.1109/mcom.2001.925668.

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38

Amuru, SaiDhiraj, and R. Michael Buehrer. "Optimal Jamming Against Digital Modulation." IEEE Transactions on Information Forensics and Security 10, no. 10 (October 2015): 2212–24. http://dx.doi.org/10.1109/tifs.2015.2451081.

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39

Pandey, R., H. Leib, and S. Pasupathy. "Noncoherently orthogonal digital phase modulation." IEEE Transactions on Communications 40, no. 6 (June 1992): 992–95. http://dx.doi.org/10.1109/26.142788.

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40

Abou Haidar, Gaby, Roger Achkar, and Hasan Dourgham. "Quality Verification of Audio and Image Modulation by the Simulation of PCM, DM and DPCM Systems." International Journal of Information and Communication Sciences 3, no. 4 (May 8, 2019): 110–20. http://dx.doi.org/10.11648/j.ijics.20180304.11.

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Modulation is a process through which a message has to pass in order to be effectively transmitted. However, there are some limitations to Pulse Code Modulation and Delta Modulation that can cause data redundancy, quantization error, slope overload distortion and granular noise which result in a bad communication process. Throughout the past few years, Pulse Code Modulation (PCM), Delta Modulation (DM) and Differential Pulse Code Modulation (DPCM), in digital communication systems, have proven to have unparalleled advantages over analog communication systems; this is in terms of error minimization and distances of transmission enhancements. Delta Modulation, a simplified version of Pulse Coded Modulation also pauses major problems in noise and quantization error. Consequently, and to combat the arising problems, communication engineers have developed newly adaptive compression and modulations techniques for better digital transmission. One of these innovative systems is the Differential Pulse Coded Modulation (DPCM) that can solve the aforementioned problems. Thus the focal point of this article is to explore the simulation of these systems using Simulink (The Math Works, Inc., USA). Eventually, the systems are tested on both image and audio inputs to prove the superiority of DPCM over DM and PCM systems in reducing noise and increasing the signal to quantization noise ratio, thus insuring a smooth and successful transfer of data.

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41

Wisland, Dag T., Mats E. Høvin та Tor S. Lande. "A Non-Feedback -Σ Modulator for Digital-to-Analog Conversion Using Digital Frequency Modulation". Analog Integrated Circuits and Signal Processing 41, № 2/3 (грудень 2004): 209–22. http://dx.doi.org/10.1023/b:alog.0000041637.75702.c3.

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42

Abdul, Rasak Zubair. "Experiments on Digital Filtering of Analog Signals: Pulse Amplitude Modulation and Delta Modulation." Global Journal of Engineering and Technology Advances 16, no. 1 (July 30, 2023): 083–98. https://doi.org/10.5281/zenodo.8285465.

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To boost students' active learning and understanding of abstract scientific concepts, hands-on learning experiences such as experiments are necessary. Computer simulations also allow students to carry out experiments virtually. Analog signals are processed using digital signal processing because of the advantages of digital signal processing over analog signal processing. Numerical experiments, results, and observations on digital band pass filtering of analog signals are presented. Two types of digital modulation are employed: Pulse Amplitude Modulation (PAM) and Delta Modulation (DM). Results demonstrated higher suppression of frequencies in the stopband compared with the transition band. Frequencies in the passband suffer minimum or no attenuation. The phase difference between input and output signals, transient response, and steady state response are observed vividly. PAM is found to add less noise to the system compared with DM. These experiments are recommended as virtual laboratory exercises for undergraduate and postgraduate studies for active learning purposes. 

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43

Xin, Yongqing, and Mirosław Pawlak. "M-Ary Phase Modulation for Digital Watermarking." International Journal of Applied Mathematics and Computer Science 18, no. 1 (March 1, 2008): 93–104. http://dx.doi.org/10.2478/v10006-008-0009-8.

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M-Ary Phase Modulation for Digital WatermarkingIn spread spectrum based watermarking schemes, it is a challenging task to embed multiple bits of information into the host signal.M-ary modulation has been proposed as an effective approach to multibit watermarking. It has been proved that anM-ary modulation based watermarking system outperforms significantly a binary modulation based watermarking system. However, in the existingM-ary modulation based algorithms, the value ofMis restricted to be less than 256, because asMincreases, the computation workload for data extraction advances exponentially. In this paper, we propose an efficientM-ary modulation scheme, i.e.,M-ary phase modulation, which reduces the computation in data extraction to a very low level. With this scheme, it is practical to implement anM-ary modulation based algorithm with a high value ofM, e.g.,M= 220. This is significant for a watermarking system, because it can either greatly increase the data capacity of a watermark given the necessary watermark robustness, or considerably improve the watermark robustness given the amount of information of the watermark. The superiority of the proposed scheme is verified by simulation results.

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44

Li, Rong. "Digital Modulation Recognition in Different Environments." Advanced Materials Research 1049-1050 (October 2014): 2084–87. http://dx.doi.org/10.4028/www.scientific.net/amr.1049-1050.2084.

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For the using of multi-modulation, the precondition of receiving and demodulating signal is to determine the type of the modulation, so automatic recognition of modulation signal has significant influence on the analysis of the signals. In this paper, digital modulation recognition is studied respectively in different environment of White Gaussian Noise (WGN), stationary interference and multipath interference. The simulation results show that the recognition success rate is the highest in stationary interference environment and the lowest in multipath interference environment with the same signal to noise ratio (SNR).

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45

Miao, Bin Ying, Zheng Ning Tang, Sha Sha Wang, and Jia Xiang Chen. "Imaging Characteristics Analysis of GLV-Based Thermal CTP System." Applied Mechanics and Materials 713-715 (January 2015): 690–93. http://dx.doi.org/10.4028/www.scientific.net/amm.713-715.690.

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The Grating Light Valve (GLV) is a spatial light modulator based on Micro Electro Mechanical Systems (MEMS), and it has been successfully applied in the computer-to-plate (CTP) system by modulating laser beams. Fast modulation rate, a mass of pixels, and high power handling capability of the GLV device increase imaging speed. Digital working states, combine of two GLV pixels and exact beam shape improve imaging quality. Numerical calculation and graph analysis using MATLAB software show that imaging quality of GLV-based thermal CTP system is higher than that of traditional acousto-optic modulator scanning system.

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46

HULA, Iho, and Oleksiy POLIKAROVSKYKH. "METHOD OF DETERMINING PARAMETERS OF MODULATION OF UAV SIGNALS USING ARTIFICIAL NEURAL NETWORKS." Herald of Khmelnytskyi National University. Technical sciences 315, no. 6 (December 29, 2022): 47–54. http://dx.doi.org/10.31891/2307-5732-2022-315-6(2)-47-54.

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The article is devoted to the consideration of the issue of determining the parameters of the modulation of signals of unmanned aerial vehicles using artificial neural networks by recognizing the types of digital modulation and is performed by a system that automatically classifies the type of digital modulation of the received signal. Recognition of digital modulation types is used, which automatically classifies the type of digital modulation of the received signal. The following issues are covered in the article: the analysis of existing approaches in the task of automatic recognition of types of digital modulation is carried out; the analysis and classification of informative features in the task of automatic recognition is carried out the following types of digital modulation: 2-PSK, 4-PSK, 8-PSK, 2-FSK, 8-QAM, 16-QAM, 64-QAM and OFDM. This article uses a neural network approach based on cumulative characteristics. To solve these problems, the methods of calculation and selection of informative cumulative features described in the developed model of the system of automatic recognition of digital modulation types by means of a neural network on cumulative features at a known value of carrier frequency are described. A model of the system of automatic recognition of digital modulation types at a known value is constructed carrier frequency. An algorithm for automatic recognition of digital modulation types has been developed using a multilayer neural network. The influence of noise in the communication channel on the probability of recognizing the types of digital modulation at a known value of the carrier frequency is investigated. It was found that regardless of the type of noise in the communication channel, the law of error distribution in IQ data becomes close to normal. This fact is one important argument for the use of cumulative features in the task of automatic recognition of types of digital modulation. Therefore, the task of automatic recognition of digital modulation types is quite relevant. Further research may be aimed at expanding the range of high-order cumulative features used, due to which it is possible to increase the probability of correct recognition of types of digital modulation, and solving the recognition problem at an unknown value of the frequency and initial phase of the carrier signal.

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47

Ghauri, Sajjad Ahmed. "KNN BASED CLASSIFICATION OF DIGITAL MODULATED SIGNALS." IIUM Engineering Journal 17, no. 2 (November 30, 2016): 71–82. http://dx.doi.org/10.31436/iiumej.v17i2.641.

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Demodulation process without the knowledge of modulation scheme requires Automatic Modulation Classification (AMC). When receiver has limited information about received signal then AMC become essential process. AMC finds important place in the field many civil and military fields such as modern electronic warfare, interfering source recognition, frequency management, link adaptation etc. In this paper we explore the use of K-nearest neighbor (KNN) for modulation classification with different distance measurement methods. Five modulation schemes are used for classification purpose which is Binary Phase Shift Keying (BPSK), Quadrature Phase Shift Keying (QPSK), Quadrature Amplitude Modulation (QAM), 16-QAM and 64-QAM. Higher order cummulants (HOC) are used as an input feature set to the classifier. Simulation results shows that proposed classification method provides better results for the considered modulation formats.

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48

Ali, Kumar &. Lal‎. "Design and Analysis of ‎Single-bit Ternary Band-pass ‎Digital Filter." Kardan Journal of Engineering and Technology 2, no. 1 (December 1, 2020): 76–85. https://doi.org/10.31841/KJET.2021.14.

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Recently, various general-purpose sigma-delta modulation based general purpose DSP algorithms have been reported that possess simpler multiplier complexity, lower power consumption and less chip area features. Here in exploration, our goal is to carry on designing a ternary-bit DSP algorithm in which significant design element is a sigma delta modulator. The formation sigma - delta (SDM) has an amount of very pleasant and attractive possessions and inborn linearity which is extensively consumed in communication systems. Signal is sampled more than that of Nyquist rate commonly word used oversampling and classically have a very short word length (i-e one-bit, binary or ternary) in sigma delta modulation technique. In this paper the design and simulation of ternary Band pass digital filter using sigma-delta modulation done in Mat-lab at different over-sampling ratio and compare it to multi-bit Band pass digital filter.

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49

M, Adarsha, S. Malathi, and Santosh Kumar. "Analysis of System Capacity and Spectral Efficiency of Fixed-Grid Network." International journal of Computer Networks & Communications 15, no. 5 (September 28, 2023): 93–111. http://dx.doi.org/10.5121/ijcnc.2023.15506.

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In this article, the performance of a fixed grid network is examined for various modulation formats to estimate the system's capacity and spectral efficiency. The optical In-phase Quadrature Modulator (IQM) structure is used to build a fixed grid network modulation, and the homodyne detection approach is used for the receiver. Data multiplexing is accomplished using the Polarization Division Multiplexed (PDM) technology. 100 Gbps, 150 Gbps, and 200 Gbps data rates are transmitted under these circumstances utilizing various modulation formats. Various pre-processing and signal recovery steps are explained by using modern digital signal processing systems. The achieved spectrum efficiencies for PM-QPSK, PM-8 QAM, and PM-16 QAM, respectively, were 2, 3, and 4 (bits/s)/Hz. Different modulation like PM-QPSK, PM-8-QAM, and PM-16-QAM each has system capacities of 8-9, 12-13.5, and 16-18 Tbps and it reaches transmission distances of 3000, 1300, and 700 kilometers with acceptable Bit Error Rate (BER≤ 2× 10-3 ) respectively. Peak optical power for received signal detection and full width at half maximum is noted for the different modulations under a fixed grind network.

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50

Su, Lin Bo, Jian Hua Chen, and Ying Peng Hu. "The Study of Coded CPM Schemes." Applied Mechanics and Materials 198-199 (September 2012): 1408–12. http://dx.doi.org/10.4028/www.scientific.net/amm.198-199.1408.

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Continuous Phase Modulation (CPM) schemes belong to a class of constant-envelope digital modulation schemes, the constant-envelope nature of the CPM signals makes them robust for the nonlinear and fading channels, and very useful for the satellite and/or the mobile radio channels. Comparing to PSK modulation, CPM modulation can not only provide spectral economy, but also exhibit a “coding gain”. CPM can be decomposed into a Continuous Phase Encoder (CPE) followed by a Memoryless Modulator (MM), this allows many new coded modulation schemes of combination of convolutional encoder and CPM modulator to be possible, such as serially-concatenated CPM (SC-CPM), SC-CPM with Convolutional Codes over Rings, pragmatic CPM (P-CPM), Concatenation of convolutional endocder and extended CE（CCEC）, etc. Some simulations show that these new CPM schemes can offer superior performance.

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