Journal articles: 'Modulation Schemes'

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Gehring, Tobias, Christian S. Jacobsen, and Ulrik L. Andersen. "Single-quadrature continuous-variable quantum key distribution." Quantum Information and Computation 16, no. 13&14 (October 2016): 1081–95. http://dx.doi.org/10.26421/qic16.13-14-1.

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Most continuous-variable quantum key distribution schemes are based on the Gaussian modulation of coherent states followed by continuous quadrature detection using homodyne detectors. In all previous schemes, the Gaussian modulation has been carried out in conjugate quadratures thus requiring two independent modulators for their implementations. Here, we propose and experimentally test a largely simplified scheme in which the Gaussian modulation is performed in a single quadrature. The scheme is shown to be asymptotically secure against collective attacks, and considers a specific attack using asymmetric preparation and excess noise. We find that this protocol is considerably more sensitive to noise than other CVQKD schemes, as a consequence of the simplified implementation. A single-quadrature modulation approach renders the need for a costly amplitude modulator unnecessary, and thus facilitates commercialization of continuous-variable quantum key distribution, provided that the low noise requirement can be achieved.

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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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BOUDOUDA, AIMAD. "POWER SPECTRAL DENSITY OF DUAL RANDOMIZED DISCONTINUOUS PULSE WIDTH MODULATION." REVUE ROUMAINE DES SCIENCES TECHNIQUES — SÉRIE ÉLECTROTECHNIQUE ET ÉNERGÉTIQUE 68, no. 2 (July 3, 2023): 132–38. http://dx.doi.org/10.59277/rrst-ee.2023.68.2.3.

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This paper addresses the spectral characteristics of a carrier-based dual randomized discontinuous pulse width modulation (DRDPWM) technique for reducing conducted EMI and switching losses in three-phase voltage source inverters. It combines two simple random schemes, random carrier frequency modulation (RCF-DPWM) and random pulse position modulation (RPP-DPWM). First, the modulating principle of the DRDPWM is presented. Then, the analytical expressions of power spectral density (PSD) that characterize the output voltage of the three-phase inverter are derived. Analytical and simulation results show the effectiveness of PSD spreading of the DRDPWM. Finally, experimental results verify the analytical and simulation results and prove the effectiveness of the DRDPWM scheme in spreading the spectrum compared to simple schemes (RPP-DPWM and RCF-DPWM) and conventional scheme DPWM.

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S. Selva Nidhyananthan, Et al. "Impact of Intense Modulation on Soliton Power Propagation across Optical Fiber and Optical Wireless Channels." Journal of Electrical Systems 20, no. 1 (February 19, 2024): 362–68. http://dx.doi.org/10.52783/jes.727.

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The optical pulse generator model in Optisystem 20 is utilized to generate an optical soliton pulse. The performance evaluation of highly modulated soliton power transmission is carried out on both optical fiber and optical wireless communication channels. The evaluation considers a flow rate of 40 Gbps and a link distance, which is not specified in the provided context. Among the proposed modulation schemes, which include CPFSK, FSK, and PSK, CPFSK demonstrates superior performance for both communication channels. Increasing the number of bits per symbol enhances the bit error rate (BER) at the fiber or wireless channel, as received by the optical receiver, for different modulation schemes, except for the CPFSK scheme. Thus, it is evident that the CPFSK modulation scheme is more efficient and outperforms other modulation schemes for various communication channels. Hence, it is evident that the CPFSK modulation scheme exhibits superior efficiency and outperforms other modulation schemes for a variety of communication channels.

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Ahmad, Husham Jawad. "Performance Evaluation and Simulation of M-Ary Quadrature Amplitude Modulation Schemes with VisSim/Comm Software." Cihan University-Erbil Scientific Journal 3, no. 2 (August 20, 2019): 58–63. http://dx.doi.org/10.24086/cuesj.v3n2y2019.pp58-63.

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M-ary modulation schemes are considered one of widely used digital modulation in practice because of its high efficiency in power and bandwidth. Therefore, this necessity the need to study and evaluate the performance of M-ary schemes using simulation techniques. In this paper, the performance of M-ary modulations schemes M-ary quadrature amplitude modulation (QAM) is considered. Because of its efficiency in power and bandwidth, M-ary QAM (M-QAM) is one of the widely used modulation techniques in practice. Therefore, a need for studying and evaluating the performance of QAM modulation schemes is an important task for designers. In this paper, M-QAM modulation schemes for even number of bits per symbol (16, 62, and 256-QAM) and an odd number of bits per symbol (32- and 128-QAM), over Additive White Gaussian Noise channel, are studied. A VisSim/Comm simulation[1] model for M-QAM is designed. Theoretical and simulation results for bit error ratio (BER) performance of QAM modulation schemes are obtained using VisSim/Comm software. The results are evaluated and compared.

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Chandra, Dikky, Fauzi Aditia Rahmat, Siska Aulia, Firdaus -, and Andre Febrian Kasmar. "Effect of Modulation on Throughput of 4G LTE Network Frequency 1800 MHz." International Journal of Advanced Science Computing and Engineering 5, no. 1 (April 10, 2023): 44–53. http://dx.doi.org/10.62527/ijasce.5.1.121.

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In the development of 4G LTE technology, network speed (Throughput) in several regions has increased or decreased. Network speed (Throughput) certainly cannot be separated from Modulation.Â In modulation there are several kinds of modulation schemes, be it QPSK modulation, 16 QAM modulation, and 64 QAM modulation. The modulation scheme is instrumental in increasing throughput. Based on several previous studies, they only check the Throughput parameters without doing a more in-depth analysis of the modulation scheme which also plays a very important role in network speed (Throughput). For this reason, it is necessary to carry out an analysis related to the effect of modulation on the throughput value. To find out the effect of modulation on throughput, it is necessary to take data in the field, the method used is the Drive Test method. Based on the results of the Drive Test, QPSK modulation has a Throughput value of 5.247.4 Kbps, modulation of 16 QAM has a Throughput value of 27.293.9 Kbps and modulation of 64 QAM has a Throughput value of 65.275.1 Kbps. Based on the data in the field and in terms of calculations, the modulation that most affects the throughput value is the modulation of 64 QAM. Modulating 64 QAM having 64 symbols where each symbol consists of 6 bits will make the data rate at throughput higher. This also applies to the use of modulation of 16 QAM (16 symbols with 4 bits) and QPSK (4 symbols with 2 bits).

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A. Eid, Mahmoud M., Ashraf S. Seliem, Ahmed Nabih Zaki Rashed, Abd El-Naser A. Mohammed, Mohamed Yassin Ali, and Shaimaa S. Abaza. "High modulated soliton power propagation interaction with optical fiber and optical wireless communication channels." Indonesian Journal of Electrical Engineering and Computer Science 21, no. 3 (March 10, 2021): 1575. http://dx.doi.org/10.11591/ijeecs.v21.i3.pp1575-1583.

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This paper has presented high modulated soliton power transmission interaction with optical fiber and optical wireless communication channels at flow rate of 40 Gbps and 20 km link range. The proposed modulation schemes are continuous phase frequency shift keying (CPFSK), Quadrature amplitude modulation (QAM), differential phase shift keying (DPSK), frequency shift keying (FSK), pulse amplitude modulation (PAM), minimum shift keying (MSK), and optical quadrature phase shift keying (OQPSK). CPFSK has presented better performance than other proposed modulation schemes for both optical fiber and optical wireless communication channels. The enhancement of optical signal/noise ratio at fiber/wireless channel, received electrical power and signal/noise ratio at optical receiver with increase of bits per symbol for different proposed modulation schemes except for CPFSK scheme. Therefore it is evident that CPFSK modulation scheme is more efficient and better performance than other modulation schemes for different communication channels. The obtained results are simulated with optisystem program version 13.

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Singh, D. Bensiker Raja, and R. SujaManimalar. "A novel impedance source inverter topology with active front-end for AC drives." Journal of Electrical Engineering 21, no. 3 (2021): 68–75. http://dx.doi.org/10.59168/iszv6642.

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A unique impedance Source Inverter with an Active Front-End is proposed in this paper, that can be used for controlling AC Drives. There are a number of modulation schemes that may be used with the three-phase impedance source inverters, ultimate reduction in the switching losses makes the discontinuous modulation schemes seem most appropriate. The discontinuous modulation schemes are differentiated into two classes based on the technique used for achieving shoot-through (ST) state: single-phase-leg ST-based and three-phase-leg ST-based (3P) discontinuous modulation schemes. In this paper, we discuss the improvements in Single Phase Maximum Boost Discontinuous Space Vector modulation (1P/MB/DSVM) scheme under similar operating conditions, by simplifying gate signal generation and improving the conversion efficiency. A simulated analysis and comparison of the conventional and the enhanced 1P/MB/DSVM schemes is also discussed using PLECS. Lastly, verification of the simulation outcomes and reported analysis is carried out by making use of a three-phase quasi-Z-source inverter (qZSI) prototype which demonstrates improvement in conversion efficiency, utilizing the refined 1P/MB/DSVM scheme.

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Su, Shi Bin, Yuan Yuan Gao, Ya Jun Zhang, Bao Feng Yang, and Ya Long Zhang. "Performance Comparison of Two Network Coding Modulation Scheme in Multiple Access Relay Cooperation." Advanced Materials Research 468-471 (February 2012): 2603–6. http://dx.doi.org/10.4028/www.scientific.net/amr.468-471.2603.

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In this paper, two different modulation schemes are developed in multiple access relay cooperation with network coding. Performance analysis and simulation results show that there is one point where the two modulation schemes have the same system outage probability. This finding can be utilized to propose an adaptive modulation scheme.

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Liao, Xuening, Zhen Jia, Zhenqiang Wu, Bo Liu, Xinlei Wang, and Xiaohong Jiang. "Modulation and Signal Detection for Diffusive-Drift Molecular Communication with a Mobile Receiver." Mobile Information Systems 2021 (December 2, 2021): 1–17. http://dx.doi.org/10.1155/2021/9656465.

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Molecular communication (MC), which allows nanomachines to communicate with each other by using chemical molecules, is considered to be a promising method for communications in liquid environment. Available works on MC mainly focus on modulation and signal detection schemes for MC systems with fixed nanomachines, i.e., fixed molecular communication (FMC) systems. However, the more complex systems with mobile nanomachines (i.e., mobile molecular communication (MMC) systems) have been largely unexplored. This paper considers a MMC system with a fixed transmitter and a mobile receiver communicating over diffusive-drift channels of a limited boundary. We first propose a new modulation scheme to address the issue of misalignment in the signal detection of MMC systems by adopting three types of molecules in the signal modulation and modulating the transmitted signals into blocks with equal length to avoid the transferring of a signal error in the current block on the signal detection in other blocks. We then propose a new signal detection scheme of the MMC systems by calculating the distance between the transmitter and the receiver based on a distance prediction method and detecting signals at the receiver based on the decided adaptive concentration threshold in each time interval. To verify the efficiency of our proposed scheme, we then conducted extensive simulations by the Monte Carlo simulation, and comparisons are also made among our proposed schemes, a well-known fixed threshold signal detection scheme, the CATD scheme, the PAD scheme, and a low complexity signal detection scheme for MMC systems in terms of the BER (bit error rate). Results show that our proposed schemes can outperform these schemes regarding the BER.

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Elsaidy, E., T. Rakia, M. Abdelaziz, and M. H. Abd El-azeem. "Low-complexity joint transmit diversity and adaptive modulation schemes for OGS-satellite FSO uplink." Journal of Physics: Conference Series 2616, no. 1 (November 1, 2023): 012043. http://dx.doi.org/10.1088/1742-6596/2616/1/012043.

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Abstract In this paper, we present two novel low-complexity transmission schemes for optical ground station (OGS)-satellite free space optical (FSO) uplink. Specifically, the TCAM-scheme which is a joint dual-branch threshold combining and adaptive modulation scheme and the SCAM-scheme which is a joint dual-branch selection combining and adaptive modulation scheme. In both schemes, the data rate is adjusted according to the instantaneous received combined SNRs at the satellite. We analyze the performance of the proposed schemes in terms of the outage probability, the average spectral efficiency and average bit error rate, while considering both subcarrirer intensity modulation/direct detection (SIM/DD) and coherent FSO detection techniques. Numerical results show that both TCAM and SCAM schemes provide better performance as compared to a single FSO uplink, while SCAM scheme enjoys better performance than TCAM scheme. This comes at the expense of increased complexity of the SCAM scheme. Also, coherent FSO detection technique shows better performance than the SIM/DD FSO detection technique for both schemes. The choice of which scheme and which FSO detection technique to use is a compromise of required quality of service and complexity.

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Quyen, Nguyen Xuan. "On the Study of a Quadrature DCSK Modulation Scheme for Cognitive Radio." International Journal of Bifurcation and Chaos 27, no. 09 (August 2017): 1750135. http://dx.doi.org/10.1142/s0218127417501358.

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The past decade has witnessed a boom of wireless communications which necessitate an increasing improvement of data rate, error-rate performance, bandwidth efficiency, and information security. In this work, we propose a quadrature (IQ) differential chaos-shift keying (DCSK) modulation scheme for the application in cognitive radio (CR), named CR-IQ-DCSK, which offers the above improvement. Chaotic signal is generated in frequency domain and then converted into time domain via an inverse Fourier transform. The real and imaginary components of the frequency-based chaotic signal are simultaneously used in in-phase and quadrature branches of an IQ modulator, where each branch conveys two bits by means of a DCSK-based modulation. Schemes and operating principle of the modulator and demodulator are proposed and described. Analytical BER performance for the proposed schemes over a typical multipath Rayleigh fading channel is derived and verified by numerical simulations. Results show that the proposed scheme outperforms DCSK, CDSK and performs better with the increment of the number of channel paths.

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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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Salau, Ayodeji Olalekan, Candidus U. Eya, and Omeje Crescent Onyebuchi. "Nonzero Staircase Modulation Scheme for Switching DC-DC Boost Converter." Journal of Control Science and Engineering 2020 (July 18, 2020): 1–15. http://dx.doi.org/10.1155/2020/8347462.

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This paper presents a novel modulation scheme known as the nonzero staircase modulation scheme for switching DC-DC boost converters. This modulation scheme generates two distinct pulse trains/firing signals when a 50 Hz nonzero staircase modulating signal is compared with a 1.5 kHz triangular wave signal. Unlike the conventional modulation schemes, the proposed novel modulation scheme provides two distinctive trains of pulse-width modulated signals for mitigating low and high harmonics. It also possesses 0.56% total harmonic distortions (THD) of the output voltage waveform system, a power output of 4591 W, and THD of 1.12% in the DC-DC boost converter system. It has a simple design and low power loss of 209 W. The proposed scheme enables the single switch boost DC-DC converter used to have an efficiency of 96%. The proposed scheme can be applied in single switch or double switch boost DC-DC converter based-hospital equipment.

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Matkar, Pratik, and Prasham Jain. "Performance Comparison of Modulation Schemes and Adaptive Modulation Scheme with CQI Feedback." International Journal of Software & Hardware Research in Engineering 6, no. 6 (June 15, 2018): 07. http://dx.doi.org/10.26821/ijshre.6.6.2018.6605.

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Ikhsan, Danang Maulana, and Theophilus Wellem. "SIMULASI SKEMA MODULASI 1024-QAM DAN 4096-QAM PADA SISTEM KOMUNIKASI DIGITAL." Jurnal Indonesia : Manajemen Informatika dan Komunikasi 4, no. 3 (September 10, 2023): 1356–64. http://dx.doi.org/10.35870/jimik.v4i3.321.

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Quadrature amplitude modulation (QAM) is a modulation scheme used by digital communication systems to obtain high data rates in bandwidth-limited channels. M-ary QAM schemes with M values greater than 256 are currently used by wireless network standards, such as WiFi 6 and WiFi 7 (final standard will be released in 2024), which use the 1024-QAM and 4096-QAM modulation schemes, respectively. With the continuous development of technology for digital communication systems, both wireline and wireless, it is essential to research regarding advanced modulation schemes. This study discusses the simulation of the 1024-QAM and 4096-QAM modulation schemes using MATLAB software to compare the performance of the two modulation schemes in data transmission through the AWGN channel without using an error control code. The simulation results show that 4096-QAM is superior to 1024-QAM but requires higher Eb/N0 and SNR values. The Eb/N0 value required by the 4096-QAM to achieve a bit error ratio (BER) of 10-4 is 31 dB, while the 1024-QAM requires an Eb/N0 value of 26 dB.

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Chakraborty, Parnasree, and C. Tharini. "Analysis of suitable modulation scheme for compressive sensing algorithm in wireless sensor network." Sensor Review 35, no. 2 (March 16, 2015): 168–73. http://dx.doi.org/10.1108/sr-06-2014-666.

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Purpose – The purpose of this paper is to find out the use of compressive sensing (CS) algorithm for wireless sensor networks (WSNs). As energy-efficient algorithms are required for WSNs, CS is very much useful as less than 25 per cent of the entire input data alone is required to be transmitted, and reconstruction at the receiver with this reduced data set is of good quality. But, the usefulness of the algorithm with suitable modulation schemes is not analyzed so far in the literature. Hence, this work concentrated on the algorithm performance with different modulation schemes and different channel conditions. Design/methodology/approach – Compressive sensing encoding is performed by using suitable transform on the input signal. Here, DCT and DWT are used to generate the sparse signal. Random measurement matrix is used to generate the compressed output, which is reconstructed using the Basis Pursuit (BP) method. Also, an analysis for the energy-efficient modulation scheme is performed by modulating the compressed output using QPSK/BPSK/QAM and transmitted by considering the Gaussian and Rayleigh Channels. Energy required per bit transmission is modeled and computed for different schemes. Findings – Simulation result shows that the use of CS algorithm for data compression tremendously reduces the number of transmission bits and, hence, enhances the transmission and bandwidth efficiency in WSN. Results show that DWT is a much suitable transform to be used for sparse measurement generation. In comparison with DCT, DWT is computationally simple and takes very less time, which is expected in real-time application. The reconstruction result shows that about 25 per cent of the data sample is sufficient to recover the original image, perhaps which is the most surprising result. An extensive analysis of various modulation schemes based on the energy model shows that QPSK is in the AWGN channel, and QAM modulation in the Rayleigh channel is a much suitable modulation scheme to be used in WSN for further reduction of energy consumption. Originality/value – Compressive sensing is recently gaining importance for quantization, compression and noise removal in images. In this paper, this technique was used along with modulation schemes to analyze the suitability of the algorithm for WSN.

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KENNEDY, MICHAEL PETER, GÉZA KOLUMBÁN, and GÁBOR KIS. "CHAOTIC MODULATION FOR ROBUST DIGITAL COMMUNICATIONS OVER MULTIPATH CHANNELS." International Journal of Bifurcation and Chaos 10, no. 04 (April 2000): 695–718. http://dx.doi.org/10.1142/s0218127400000499.

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This tutorial work identifies the characteristic properties of chaotic digital modulation schemes and shows how the unique features of chaotic basis functions can be exploited to competitive advantage in selected application domains. Two robust noncoherent chaotic digital modulation schemes (DCSK and FM-DCSK) are described in detail and the performance of FM-DCSK is examined critically for communication channels where systems using conventional coherent and narrow-band modulation schemes fail. Since the FM-DCSK signal is a wide-band signal and its demodulation is performed without synchronization, the FM-DCSK modulation scheme is especially suitable for operation in multipath channel such as Wireless Local Area Networks (WLANs).

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Gao, Jianbang, Bin Qiu, and Jing Zhou. "Spatial Modulation and MP-WFRFT-Aided Multi-Beam Wireless Communication Scheme Based On Random Frequency Diverse Array." Sensors 20, no. 18 (September 16, 2020): 5289. http://dx.doi.org/10.3390/s20185289.

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A security-enhanced, spectral-efficient, and power-efficient multi-beam wireless communication scheme based on random frequency diverse array (RFDA) is proposed in this paper. (AN)-aided directional modulation (DM) schemes. Furthermore, with the aid of spatial modulation (SM) technology and cooperative legitimate users (LUs), we can transmit more information bits by the use of LU number informations than the single modulation symbols. Unlike conventional zero-forcing (ZF) beamforming for multi-beam DM, we design a FDA beamforming vector for each LU based on the minimum transmit power method. Numerical simulations show that (1) the proposed scheme is power-efficient compared to the conventional schemes, (2) the proposed scheme can transmit more information bits than the conventional schemes, and (3) the proposed scheme can ensure communication security when eavesdroppers (Eves) are proximal to LUs or even in same locations.

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Kumar, Parvesh, Shalini Bhadola, and Kirti Bhatia. "Evaluation of BER in LTE System using Various Modulation Techniques over different Modulation Schemes." International Journal of Trend in Scientific Research and Development Volume-3, Issue-3 (April 30, 2019): 1325–29. http://dx.doi.org/10.31142/ijtsrd23315.

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Yousaf, Jawad, Muhammad Faisal, Wansoo Nah, Mohammed Ghazal, Rana Sarmad Mahmmod, and Hatem Rmili. "Effects of Random Switching Schemes on the EMI Levels of Conventional and Interleaved Buck Converters for Mobile Devices." Electronics 11, no. 3 (January 19, 2022): 306. http://dx.doi.org/10.3390/electronics11030306.

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This study presents a comprehensive detailed analysis of the effect of five different random modulation switching schemes and their randomness levels on the elector magnetic interference (EMI) of designed simple and interleaved DC-DC buck converters for smartphone applications. The analyzed switching schemes are pulse width modulation (PWM), random pulse width modulation (RPWM), random pulse position modulation (RPPM), random carrier frequency modulation various duty (RCFMVD), and random carrier frequency modulation fixed duty (RCFMFD). The experimental analysis is performed for all aforementioned switching modulation schemes at the switching frequency of 20 kHz and different randomness levels (RL) (30% to 85%). For a fixed RL of 40%, the switching current harmonics/conducted emission (CE) levels are 5–10 dB/11 dBμV and 17 dB/14 dBμV lower for the RCFMVD case when compared to conventional PWM for both simple and interleaved buck-converters, respectively. The observed switching current harmonics and CE levels for interleaved schemes are around 23 dB and 12 dBμV lower when compared to the conventional simple buck converter scheme for the analyzed circuit configurations. The EMI levels decrease with the increase in the randomness levels from 30% to 85% with less variations in the output voltage level. The findings suggest that a interleaved buck converter circuit with the least-independent switching mechanisms and higher randomness is more appropriate for the reduction of both current spikes and CE levels with RCFMFD as the switching modulation scheme.

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Pidikiti, Tripura, and Tulasi Ram Das G. "Modelling and simulation of ZDC controlled PMSG based wind energy conversion system." International Journal of Engineering & Technology 7, no. 1.8 (February 9, 2018): 46. http://dx.doi.org/10.14419/ijet.v7i1.8.9449.

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This paper presents the comparison of dynamic performance and steady state operation of PMSG wind energy conversion systems with two modulation techniques. Voltage oriented control (VOC) is used for grid-connected converter along with sinusoidal pulse width modulation (SPWM) and Space Vector Modulation (SVM) schemes. The generator is controlled by using zero d- axis current (ZDC) control scheme along with optimal torque control (OTC). Performance comparison with two pulse width modulation schemes through simulation results are presented for 2MW/ 690V/ 9.75Hz Non-Salient Pole PMSG using MATLAB/SIMULINK.

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U. Eya, Candidus, Ugwuanyi Oliver O., and Omeje Crescent O. "An Improved Conventional Diode-Clamped Multilevel Inverter Using Non-Zero Triangular- Based Unipolar Modulation Scheme." WSEAS TRANSACTIONS ON SYSTEMS AND CONTROL 17 (February 21, 2022): 91–100. http://dx.doi.org/10.37394/23203.2022.17.11.

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This paper presents an improved conventional diode-clamped multilevel inverter using non-zero triangular-based unipolar modulation scheme. The proposed scheme is meant to reduce the number of carrier waves, minimize the circuits of modulation scheme and obtain stabilized output voltage waveforms. Non-zero triangular-based unipolar modulation scheme is actualized by using two zero-free triangular wave carriers and two modulating sinewaves for line-to- line five level output voltage waveforms in single phase full bridge diode-clamped multilevel inverter unlike conventional multicarrier sinusoidal pulse width modulation that uses four triangular waves and one modulating sinewave for the same inverter type. The proposed system also used microcontroller in the combinational of its wave signals in order to generate the appropriate triggering signals for switching the power semiconductor switches. The proposed system has the following features: (i) It produces two distinct triggering trains (W1 and W2) meant to reduce the low and high harmonics unlike conventional modulation techniques (ii) All its carrier waves operate in continuous current mode which makes it unique from other multicarrier and other related modulation schemes (iii) it has low component counts. The proposed scheme on the conventional diode-clamped inverter produced the following results: voltage and current with total harmonic distortions of 0.4547%, stabilized 400V output voltage and 20A output current, probability results at each level of voltage and current occurrences are 0.10, 0.25, 0.25, 0.75 and 0.90; power output of 80kW, low component counts of modulation circuit scheme and experimental prototype.

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Kumar, Arun, and Dr Manisha Gupta. "COMPARATIVE STUDY AND ANALYSIS OF BER OF CDMA FOR DIFFERENT MODULATION SCHEME." INTERNATIONAL JOURNAL OF COMPUTERS & TECHNOLOGY 12, no. 8 (March 4, 2014): 3839–43. http://dx.doi.org/10.24297/ijct.v12i8.3013.

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With the increasing demand in wireless communication, it has become necessary to give better and efficient service to users by using better technique. This paper propose and analyse the bit error rate of CDMA, for different modulation schemes such as BPSK, QPSK and QAM. By Choosing a reliable modulation scheme and better filtration Technique the enhancement of the performance can be obtained in transmitter and receiver of CDMA system. Simulated result is shown to analyse and compare the performance of these systems by using additive white Gaussian noise channel (AWGN).Finally the different modulation schemes is compared on the basis of BER and best modulation scheme is determined. Â From analysis of three modulation techniques, the system could use more appropriate modulation technique to suit the channel quality, thus we can deliver the optimum and efficient data rate to mobile terminal.

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El-Hageen, Hazem M., Aadel M. Alatwi, and Ahmed Nabih Zaki Rashed. "Advanced modulation coding schemes for an optical transceiver systems–based OWC communication channel model." Bulletin of Electrical Engineering and Informatics 10, no. 2 (April 1, 2021): 767–75. http://dx.doi.org/10.11591/eei.v10i2.2433.

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This paper examines advanced modulation coding schemes for an optical transceiver systems–based optical wireless communication (OWC) channel model. These modulation techniquesinclude On-Off keying and return to zero (RZ)/non–return to zero (NRZ) coding. The signal power level against time and frequency spectral variations are measured. The max. Q factor and min. bit error rate (BER) are estimated and clarified for each modulation code scheme by using an optisystem simulation model. Transmission bit rates of up to 40 Gb/s can be achieved for possible distances up to 500 km with acceptable Q factor. The received power and max. Q factor are measured and clarified with OWC distance variations. The On-Off keying modulation code scheme resulted in better performance than the other modulation code schemes did.

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Zahra, Anam, and Qasim Umar Khan. "Performance Comparison of Digitized Quaternion Modulation with other Modulation Schemes." ITM Web of Conferences 27 (2019): 01004. http://dx.doi.org/10.1051/itmconf/20192701004.

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In wireless networks signal’s security from noise has been a very challenging issue, primarily because of the broadcast nature of communication. This paper focuses on digitized Quaternion Modulation (QM) which gives better performance as compared to QPSK, QAM and QFSK. We compare the performance of quaternion modulation with other modulation schemes in terms of BER using idealistic Additive White Gaussian Noise AWGN channel. This scheme can be used in applications such as Global Positioning System (GPS), satellite and space communication system to reduce errors. The simulation results show superior performance of the proposed digitized Quaternion Modulation over its counterparts. Thus one may trade off bandwidth for BER.

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Boudouda, Aimad, Nasserdine Boudjerda, and Fares Nafa. "Analysis of output voltage ripple for dual randomized PWM buck converter operating in continuous and discontinuous conduction modes." Acta Polytechnica 62, no. 2 (May 5, 2022): 262–73. http://dx.doi.org/10.14311/ap.2022.62.0262.

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Dual Randomized Pulse Width Modulation (DRPWM) is renowned for its better effectiveness than Simple Randomized Pulse Width Modulation (SRPWM) in reducing conducted Electro-Magnetic Interferences (EMI) in power converters. However, the introduction of low-frequency ripples into the output voltage by dual randomization has not yet been addressed; this effect is investigated in this paper for a buck converter operating in both the continuous conduction mode (CCM) and the discontinuous conduction mode (DCM). First, the modulating principle is presented. Then, a general analytical expression for power spectral density (PSD) of the input current is derived and validated for the proposed DRPWM scheme for both the CCM and DCM. A comparison of the PSDs of the input current for all RPWM schemes in both the CCM and DCM shows the PSD spreading effectiveness of the dual scheme as compared to simple schemes. Finally, the low-frequency output ripple is analysed using the PSD of output voltage. The results reveal that the output voltage ripple is affected by all the randomized schemes in both the CCM and the DCM. Also, the dual scheme (RCFM-RPPM) introduces the highest low-frequency voltage ripple, especially in the CCM and for low duty cycles. In DCM, the RPPM scheme gives the lowest voltage ripple, while the RCFM scheme gives the lowest voltage ripple in the CCM. The results are confirmed by both theory and simulations.

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Eya, Candidus U., Ayodeji Olalekan Salau, Sepiribo Lucky Braide, S. B. Goyal, Victor Adewale Owoeye, and Oluwafunso Oluwole Osaloni. "Assessment of Total Harmonic Distortion in Buck-Boost DC-AC Converters using Triangular Wave and Saw-Tooth based Unipolar Modulation Schemes." WSEAS TRANSACTIONS ON POWER SYSTEMS 17 (November 8, 2022): 324–38. http://dx.doi.org/10.37394/232016.2022.17.33.

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This paper presents an assessment of the levels of total harmonic distortion (THD) in buck-boost DC-AC converters using triangular wave and saw-tooth unipolar based-modulation schemes. This paper seeks to identify a better technique for mitigating the total harmonic distortion on buck-boost DC-AC converters under unipolar carrier-based modulation schemes. This was achieved by subjecting the buck-boost DC-AC converter under triangular wave-based and saw-tooth based-unipolar modulation schemes. The voltage and current output of the buck- boost DC-AC converter under each scheme was analysed using a power GUI Fast Fourier Transform (FFT) analytical tool resident in the MATLAB Simulink environment unlike with the conventional scheme of computing the percentage of THD. The test system was obtained by a combination of DC-DC buck-boost converter, H-bridge based-insulated unipolar gate transistors, and a logic control unit. It was realized that THD of 0.2865%, peak output voltage of 294.1V and current of 9.805A were obtained by using the saw-tooth based-unipolar modulation scheme, whereas a THD of 0.1479%, peak output voltage of 297.4V and current of 9.53A were obtained by using the triangular wave based-bipolar modulation scheme on the same Buck-boost DC-AC converter circuit. The results imply a high power factor utilization and low power loss in the triangular wave based-unipolar modulation scheme compared to the saw-tooth based-unipolar modulation technique for improving the performance characteristics of the buck-boost converter system. This study showed that power drives and heavy load machines based-power electrical loads are required to use the saw-tooth based-unipolar modulation (STBUM) scheme for high current and low THD%, whereas sensitive power electrical loads such as hospital equipment and communication industries based-power electronic devices are required to use the triangular wave-based unipolar modulation (TWBUM) scheme due to low current and THD%.

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Sud, Seema. "High Order Chirp Rate Shift Keying Modulation Using the Fractional Fourier Transform." European Journal of Engineering Research and Science 2, no. 4 (April 14, 2017): 1. http://dx.doi.org/10.24018/ejers.2017.2.4.314.

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In this paper, we discuss an improved demodulation scheme using the Fractional Fourier Transform (FrFT) for a modulation scheme employing chirp rate shift keying (CrSK). CrSK in conjunction with the FrFT enable very high order, e.g. more than 32-ary modulation schemes to be achievable with good bit error rate (BER) performance, even in the absence of coding, thereby overcoming limitations of traditional schemes including phase shift keying (PSK) or QAM (quadrature amplitude modulation). By using an FrFT-based demodulator, we expand our demodulation degrees of freedom from a single (e.g. frequency) axis to an entire time-frequency domain, called the Wigner Distribution (WD). We show how the proposed demodulation scheme using the FrFT improves over past approaches by more than 7 dB, enabling us to achieve close to 4-ary performance with a 32-ary modulation scheme. This enables future systems to operate at 5 bits/s/Hz bandwidth efficiency, enhancing bandwidth utilization for future generation, high data rate, applications, such as internet.

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Sud, Seema. "High Order Chirp Rate Shift Keying Modulation Using the Fractional Fourier Transform." European Journal of Engineering and Technology Research 2, no. 4 (April 14, 2017): 1–5. http://dx.doi.org/10.24018/ejeng.2017.2.4.314.

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In this paper, we discuss an improved demodulation scheme using the Fractional Fourier Transform (FrFT) for a modulation scheme employing chirp rate shift keying (CrSK). CrSK in conjunction with the FrFT enable very high order, e.g. more than 32-ary modulation schemes to be achievable with good bit error rate (BER) performance, even in the absence of coding, thereby overcoming limitations of traditional schemes including phase shift keying (PSK) or QAM (quadrature amplitude modulation). By using an FrFT-based demodulator, we expand our demodulation degrees of freedom from a single (e.g. frequency) axis to an entire time-frequency domain, called the Wigner Distribution (WD). We show how the proposed demodulation scheme using the FrFT improves over past approaches by more than 7 dB, enabling us to achieve close to 4-ary performance with a 32-ary modulation scheme. This enables future systems to operate at 5 bits/s/Hz bandwidth efficiency, enhancing bandwidth utilization for future generation, high data rate, applications, such as internet.

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Bakulin, Mikhail G., Taoufik Ben Rejeb, Vitaly B. Kreyndelin, Yuriy B. Mironov, Denis Y. Pankratov, and Alexey E. Smirnov. "Modulation for cellular 5G/IMT-2020 and 6G networks." T-Comm 16, no. 3 (2022): 11–17. http://dx.doi.org/10.36724/2072-8735-2022-16-3-11-17.

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In recent years, 5G (Fifth Generation) and 6G (Sixth Generation) wireless networks have attracted extensive research interest. According to the 3GPP (3rd Generation Partnership Project) project, 5G networks should be support three main application scenarios: enhanced Mobile Broadband (eMBB), Massive Machine-Type Communications, (mMTC), Ultra-Reliable Low Latency Communication (URLLC). In addition to that, enhanced vehicle-to-everything, (eV2X) are also considered as key technology in 5G. All these scenarios require ubiquitous connectivity providing high data rates and spectral efficiency. These issues lead to many challenges for introducing 5G and 6G networks. Traditional modulation and multiple access schemes will not achieve the requirements of 5G and 6G networks. In order to meet these upcoming requirements, it is necessary to explore novel modulation and multiple access schemes. Data rate, resistance to noise and capacity of wireless network depend on choosing current modulation scheme. To meet the requirements of 5G and 6G and reduce the out-of-band (OOB) leakage various modulation schemes based on subband filtering, pulse shaping and precoding have been proposed. This article provides an overview of the different modulation schemes for 5G and 6G systems.

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Ahmed, Abu Shakil, Husam Al-amaireh, and Zsolt Kollar. "Multicarrier Modulation Schemes for 5G Wireless Access." ECTI Transactions on Computer and Information Technology (ECTI-CIT) 16, no. 4 (September 24, 2022): 378–92. http://dx.doi.org/10.37936/ecti-cit.2022164.248710.

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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.

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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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Wyrowski, Frank. "Modulation schemes of phase gratings." Optical Engineering 31, no. 2 (1992): 251. http://dx.doi.org/10.1117/12.56080.

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Jiang, Chao, Xiao Gang Chen, and Zhao Xu Liu. "Effect of Modulation Index of Mach-Zehnder Modulator on Single Sideband Radio over Fiber System." Advanced Materials Research 756-759 (September 2013): 2350–53. http://dx.doi.org/10.4028/www.scientific.net/amr.756-759.2350.

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The effect of the modulation index of Mach-Zehnder modulator on single sideband (SSB) radio over fiber (RoF) system is investigated, and two different data modulation schemes are considered. The quantitative results suggest that there exist an optimum modulation index, and the system performance could be improved if the data signal is modulated on only optical carrier or sideband.

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M. Alatwi, Aadel, and Ahmed Nabih Zaki Rashed. "A pulse amplitude modulation scheme based on in-line semiconductor optical amplifiers (SOAs) for optical soliton systems." Indonesian Journal of Electrical Engineering and Computer Science 21, no. 2 (February 1, 2021): 1014. http://dx.doi.org/10.11591/ijeecs.v21.i2.pp1014-1021.

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The objective of this work is to simulate a pulse amplitude modulation (PAM) scheme based on in-line semiconductor optical amplifiers for optical soliton systems. The max. power for soliton systems, based on various bits/symbol PAM modulation schemes after a fiber length of 100 km, is simulated and clarified. In addition to the max. Q factor for soliton systems, PAM modulation schemes with various in-line SOA injection currents and a fiber length of 100 km are also simulated and demonstrated in the results. The total electrical power after photo-detectors for soliton systems, based on PAM modulation schemes with various in-line SOA injection currents and a fiber length of 100 km, is also simulated and clarified in the results. The study emphasizes that the higher the SOA injection current, the higher the electrical power and the lower the Q factor that can be achieved in the soliton system.

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Liu, Zhao Xu, Xiao Gang Chen, and Chao Jiang. "Performance Evaluation of Optical Carrier Suppression Radio over Fiber System through Modulation Index Enhancement." Advanced Materials Research 756-759 (September 2013): 1190–93. http://dx.doi.org/10.4028/www.scientific.net/amr.756-759.1190.

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The performance of optical carrier suppression (OCS) radio over fiber (RoF) system is evaluated through tuning the modulation index of Mach-Zehnder modulator, and two different data modulation schemes are considered. The quantitative simulation results validate that there exist an optimum modulation index, and the system performance could be improved if the data signal is modulated on only one of two sidebands.

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Xue, Yukang, and Yahong R. Zheng. "Orthogonal time-frequency space (OTFS) modulation for underwater mobile acoustic communications." Journal of the Acoustical Society of America 154, no. 4_supplement (October 1, 2023): A249. http://dx.doi.org/10.1121/10.0023445.

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This paper investigates the Orthogonal Time-Frequency Space (OTFS) Modulation for Underwater Mobile Acoustic Communications where the communication channel suffers from severe multipath and Doppler effects simultaneously. Practical OTFS modulation schemes with different parameters are designed for acoustic transmission at a center frequency of 115 kHz and a bandwidth of 11.5 kHz. The schemes are tested in lake experiments where the transmitter was anchored and the receiver was towed by a boat at a speed of approximately 1 m/s or 3.6 km/h. The receiver utilizes low-complexity channel estimation and equalization algorithms, such as NLMS (Normalized Least Mean Squares) and IPNLMS (improved proportionate NLMS) algorithms. The results show some insights of the OTFS scheme for acoustic communications. First, the mobile acoustic channel characteristics are different in the 2D delay-Doppler domain than those in the 1D time and frequency domains for the Single-Carrier Coherent Modulation (SCCM) and the Orthogonal frequency division modulation (OFDM), respectively. Second, in mobile scenarios, the OTFS scheme receiver effectively and significantly reduces the accuracy requirements of the Doppler compensation algorithm and provides better frequency-selective fading suppression and Doppler effect robustness compared to SCCM and OFDM schemes. Third, the OTFS scheme has better anti-multipath performance and reduces multipath interference by effectively differentiating signals on different paths in the 2D delay-Doppler domain.

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Goswami, Raj Kumar, Srinivasa Rao Kandula, S. V. Rama Rao, A. H. Sharief, Koteswararao Seelam, Sunil Babu Melingi, and Swathi Nambari. "Design of Turbo Trellis Coding Modulation Scheme of Rate 4/9 for Rician Fading Channel." International Journal on Recent and Innovation Trends in Computing and Communication 11, no. 6 (July 24, 2023): 198–203. http://dx.doi.org/10.17762/ijritcc.v11i6.7382.

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When the fading channels are encountered during data communication, errors are likely to occur at the receiving end due to multipath propagation. Researchers have been consistently striving to develop Error Correction Schemes that can effectively handle these errors and ensure error-free data reception at the receiver end. Of particular interest are the Forward Error Correction Schemes that can be implemented at the transmitter end itself. However, the implementation of error correction coding through these schemes incurs additional costs in terms of bandwidth expansion, as extra bits need to be added to facilitate error correction. Fortunately, there exists one coding scheme called Trellis Coded Modulation (TCM), which addresses this issue. TCM selects a modulation scheme based on the rate of the convolutional coding scheme. However, this coding technique has limitations in correcting the number of errors, leading to the development of Turbo Coding. This scheme utilizes two coders at the transmitter, arranged in either serial or parallel configuration, and a suitable decoder at the receiver. A design of Turbo Coding scheme has been presented in this paper, that employs convolutional coders having rate 2/3, in a serially concatenated configuration, providing an effective rate of 4/9. This turbo coding scheme is then applied to TCM scheme in order to preserve the bandwidth. Therefore, if using the convolutional coding scheme of rate 2/3, the modulation scheme is 8-QAM and in order to preserve bandwidth after coding, using the Turbo coding scheme of rate 4/9, then the modulation scheme will be 512-QAM. The simulations have been conducted in MATLAB and the error correcting capabilities of the designed scheme in comparison with convolutional coding scheme using the constituent convolutional encoder have also been compared. It has been observed that in the Rician fading channel conditions, the Turbo Trellis Coding Modulation Scheme provides approximately 5 dB gain compared to the convolutional coding scheme.

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Harrye, Yasen, Ahmed Abdalla, and Hassan A. Mahasneh. "The Generalization of Bidirectional Dual Active Bridge DC/DC Converter Modulation Schemes: State-of-the-Art Analysis under Triple Phase Shift Control." Energies 16, no. 22 (November 14, 2023): 7577. http://dx.doi.org/10.3390/en16227577.

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The main objective of this paper is to provide a thorough analysis of currently used modulation control schemes for single-phase bidirectional dual active bridge DC/DC converters. In this article, it will be shown that single phase shift, extended phase shift and dual phase shift modulation schemes are special cases of the triple phase shift (TPS) modulation scheme. The article aims to highlight six TPS switching modes and their complements with operational constraints. Unlike previous studies that regarded TPS as a complex scheme, this paper simplifies the analysis of each mode and aims to standardize the understanding of TPS modulation for dual active bridge (DAB) converters. Power equations, range of power transferred and zero-voltage switching (ZVS) are derived for all the modes under TPS without assuming fundamental component analysis. Additionally, a generic optimization algorithm is developed to show the advantages of TPS modulation, and thus, the analysis in this paper offers a valuable insight for single-phase DAB converter designers in identifying a wide range of optimization algorithms to achieve higher efficiency under TPS modulation. This analysis contributes to the advancement of bidirectional DAB converter technology and facilitates its application in various power electronic systems.

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Goswami, R. K., K. Srinivasa Rao, and Swathi Nambari. "Implementation of Turbo Trellis Coding Modulation Scheme for Fading Channel." International Journal of Electrical and Electronics Research 11, no. 3 (July 30, 2023): 669–74. http://dx.doi.org/10.37391/ijeer.110305.

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In the context of data communication, encountering fading channels can lead to errors occurring at the receiving end due to multipath propagation. To address this challenge, researchers have persistently worked towards developing Error Correction Schemes that effectively manage these errors and guarantee error-free data reception for the receiver. One area of focus lies in the implementation of Forward Error Correction Schemes directly at the transmitter end. Nonetheless, integrating error correction coding using these schemes comes with the drawback of increased bandwidth requirements since additional bits must be included to facilitate error correction. Fortunately, there exists a coding scheme known as Trellis Coded Modulation (TCM), which specifically tackles this concern. In the case of TCM, the modulation scheme has been chosen based on the rate of the convolutional coding scheme. Nevertheless, TCM has certain limitations when it comes to correcting a high number of errors, which prompted the emergence of Turbo Coding. Turbo Coding employs two coders at the transmitter, arranged either in a serial or parallel configuration, along with an appropriate decoder at the receiver. This paper introduces a Turbo Coding scheme design utilizing convolutional coders with a rate of 2/3, arranged in a serially concatenated configuration, resulting in an effective rate of 4/9. For preserving bandwidth, the Turbo Coding is applied to TCM scheme. Consequently, when employing the convolutional coding scheme with a rate of 2/3, the modulation scheme has to be 8-QAM. However, to maintain bandwidth after coding, when utilizing the Turbo coding scheme with a rate of 4/9, the modulation scheme is upgraded to 512-QAM. MATLAB simulations were conducted to evaluate the error correcting capabilities of the designed scheme compared to the convolutional coding scheme that uses the constituent convolutional encoder. The comparison has also been made with the uncoded data communication utilizing simple QPSK modulation scheme. The results indicate that under Rician fading channel conditions, the Turbo Trellis Coding Modulation Scheme provides an approximate gain of 5 dB compared to the convolutional coding scheme and approximately 8 dB gain compared to uncoded one.

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Husaini, M. M. H., C. B. M. Rashidi, SN Azemi, S. A. Aljunid, and M. S. Anuar. "Optical millimeter wave generation utilizing stimulated brillouin scattering for radio over fiber system." Indonesian Journal of Electrical Engineering and Computer Science 13, no. 2 (February 1, 2019): 818. http://dx.doi.org/10.11591/ijeecs.v13.i2.pp818-824.

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Optical millimeter-wave signal generation in Radio over Fiber (RoF) based on external modulators using different modulation schemes such as Single-Sideband (SSB), Double-Sideband (DSB) are experimentally compared. The major fallout for external modulation scheme system performance to downgrade is due to dispersion and the fading effect in optical signal generation while generating high Bit Error Rate (BER) when involving long distance delivery. In this work, we proposed mm-wave signal utilize Stimulated Brillouin Scattering (SBS) scheme which indicates the best performance amongst the scheme based on simulation that it achieves to propagate longest of distance over fiber, highest receiver sensitivity, the lowest BER and coherence of Mach-Zehnder Modulator (MZM) extinction ratio. Mm-wave signal of 40 Ghz and 10 Gb/s data rate was generated with the plotting of eye diagram.

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Zhang, Peidong. "System optimization for index modulated OFDM." Highlights in Science, Engineering and Technology 53 (June 30, 2023): 88–97. http://dx.doi.org/10.54097/hset.v53i.9686.

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This paper introduces the system optimization scheme of OFDM-IM, an emerging modulation technology that combines OFDM technology and modulation index technology to improve spectral efficiency and system reliability while ensuring high-speed transmission. However, as a new technology, OFDM still has shortcomings. This paper investigates three system optimization schemes for OFDM-IM: he deep learning-based OFDM-IM optimization scheme, MIMO-OFDM-IM, and LDPC coding-assisted subcarrier index protection scheme. It is found that these three optimization schemes are indeed helpful for optimizing the performance of OFDM-IM through system simulation experiments. The IM-OFDM system optimization based on deep learning is very helpful for IM-OFDM in terms of channel estimation, signal detection, and modulation classification. MIMO-OFDM-IM can increase channel capacity and signal transmission reliability. By protecting the subcarrier index, LDPC codes can effectively reduce the subcarrier error rate and improve the reliability and performance of IM-OFDM systems. Due to their different technical characteristics, the three optimization schemes have different advantages. They also have their application scenarios in which they excel. However, considering these technologies are relatively new, there are still certain drawbacks to these three technologies. Researchers need to continue to study them in-depth and gradually overcome them.

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Jirnadu, Theman Ibrahim, Adeyemi Abel Ajibesin, and Ahmed T. Ishaq. "Comparative Analysis of QAM Modulation Techniques over AWGN and Fading Channels." Advances in Science and Technology 107 (June 28, 2021): 194–200. http://dx.doi.org/10.4028/www.scientific.net/ast.107.194.

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Although, most researchers focus on some of the key components of good digital wireless communications which are the Bit Error Rate (BER) versus Signal to Noise Ratio (SNR) of modulation schemes. Energy consumption optimization is necessary for enhancing the performance of a wireless communication system as it offers numerous advantages to the system and the users. Therefore, this research focuses on analyzing the efficiency in the performance of the various QAM Modulation Schemes (4QAM, 16QAM, 32QAM & 64QAM) as they travel over noise/fading channels with the quest to obtain an energy-efficient scheme which will enhance system performance in terms of system runtime and quality of service. The efficiency of any given process, operation, or device is rated per the energy it consumes in carrying out an activity per unit output. Hence, the objective of this research work is to study and analyze comparatively the efficiency of these modulation schemes and to conclude with the most efficient scheme over the various channels. The evaluation of the Bit Error Rate (BER) versus energy per bit to noise spectral density (EbNo) for each communication scenario was carried out in MATLAB.

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Pruthi, Juhi, Pooja Agarwal, and Nikita Jain. "Impact of Modulation Schemes on LTE." International Journal of Computer Applications 115, no. 15 (April 22, 2015): 36–39. http://dx.doi.org/10.5120/20231-2529.

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Wei, Ruey-Yi, Yi-Wei Tsai, and Shih-Lun Chen. "Improved Schemes of Differential Spatial Modulation." IEEE Access 9 (2021): 97120–28. http://dx.doi.org/10.1109/access.2021.3095531.

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Renyuan Li and G. Stette. "Time-limited orthogonal multicarrier modulation schemes." IEEE Transactions on Communications 43, no. 2/3/4 (February 1995): 1269–72. http://dx.doi.org/10.1109/26.380167.

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Torres Nova, Juan Mario, and Hernán Paz Penagos. "Studying and comparing spectrum efficiency and error probability in GMSK and DBPSK modulation schemes." Ingeniería e Investigación 28, no. 3 (September 1, 2008): 75–80. http://dx.doi.org/10.15446/ing.investig.v28n3.15123.

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Gaussian minimum shift keying (GMSK) and differential binary phase shift keying (DBPSK) are two digital modulation schemes which are -frequently used in radio communication systems; however, there is interdependence in the use of its benefits (spectral efficiency, low bit error rate, low inter symbol interference, etc). Optimising one parameter creates problems for another; for example, the GMSK scheme succeeds in reducing bandwidth when introducing a Gaussian filter into an MSK (minimum shift ke-ying) modulator in exchange for increasing inter-symbol interference in the system. The DBPSK scheme leads to lower error pro-bability, occupying more bandwidth; it likewise facilitates synchronous data transmission due to the receiver’s bit delay when re-covering a signal.

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Christopher, Chembe, Rafidah Md Noor, and Ehsan Mostajeran. "Optimizing Wireless Channel Using Adaptive Modulation To Improve QoS In VANET." Malaysian Journal of Computer Science 26, no. 1 (March 1, 2013): 34–43. http://dx.doi.org/10.22452/mjcs.vol26no1.4.

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Vehicular Ad Hoc Network (VANET) is a multi-hop wireless network which involves vehicles acting as nodes to communicate with each other without infrastructural support. With the increase in Quality of Service (QoS) needs in evolving applications and the widespread use of wireless and mobile devices, it is desirable to support QoS in VANETs. The resource limitations and variability further add to the need for QoS support in such networks. However, the characteristics of these networks make QoS support a complex process due to rapid topology changes caused by high mobility of communicating nodes. Modulation scheme implemented in wireless network affect the data rate hence the throughput of the communicating nodes, this in turn affect QoS. The paper focuses on adaptive modulation to improve the data throughput and efficiency of channel spectrum in VANET. Through theoretical and simulation results, it was shown that adaptive modulation performs well and improves throughput than other modulations schemes when used singularly in dynamic changing network topology like VANET.

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Francis, Henry, Si Chen, Kai-Jun Che, Mark Hopkinson, and Chaoyuan Jin. "Photonic Crystal Cavity-Based Intensity Modulation for Integrated Optical Frequency Comb Generation." Crystals 9, no. 10 (September 25, 2019): 493. http://dx.doi.org/10.3390/cryst9100493.

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A simple scheme to generate an integrated, nanoscale optical frequency comb (OFC) is numerically studied. In this study, all optical intensity modulators based on photonic crystal (PhC) cavities are cascaded both in series and parallel. By adjusting the modulation parameters, such as the repetition rate, phase, and coupling efficiency of the modulating wave, it is possible to produce combs with a variety of different characteristics. Unique to PhC intensity modulators, in comparison with standard lithium niobate modulators, is the ability to control the amplitude of the light via a cavity rather than controlling the phase through one arm of a Mach–Zehnder interferometer. This opens up modulation-based OFC generation to new possibilities in both nanoscale operation and cavity-based schemes.

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Journal articles on the topic 'Modulation Schemes'

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