scholarly journals Design of Digital Pulse-Position Modulation System

2021 ◽  
Vol 2093 (1) ◽  
pp. 012030
Author(s):  
Nanjun Yu ◽  
Pengzhao Wang ◽  
Zhiyi Zhuang
Keyword(s):  
Gaussian Noise ◽  
Pulse Sequence ◽  
Pulse Signal ◽  
Modulation Method ◽  
Pulse Position Modulation ◽  
Matlab Simulation ◽  
Advantages And Disadvantages ◽  
Transmission Process ◽  
Digital Pulse ◽  
Modulation Methods

Abstract Pulse-Position Modulation (PPM) is a modulation method that only makes every pulse in the carrier pulse sequence change with time but without changing the shape and amplitude of the pulse signal. In this paper, a PPM system is designed. Firstly, an appropriate mathematical model is established to represent PPM transmission, and the shape of the pulse signal is designed. After that, we write the code and add a white Gaussian noise channel. Then the transmission process is simulated and visualized. At last, the error rate of the scheme is analyzed and discussed through MATLAB simulation then compared with other modulation methods. The goal of this paper is to study PPM by designing a PPM system fully. Besides, our method is compared with other modulation methods to understand the advantages and disadvantages of PPM. This may help other scholars to design and research the PPM system.

scholarly journals Application of Ultra Narrow Band Modulation in Enhanced Loran System

Sensors ◽  
2021 ◽  
Vol 21 (13) ◽  
pp. 4347
Author(s):  
Boyun Lyu ◽  
Yu Hua ◽  
Jiangbin Yuan ◽  
Shifeng Li
Keyword(s):  
Narrow Band ◽  
Data Rate ◽  
Modulation Method ◽  
Phase Shift Keying ◽  
Spectrum Utilization ◽  
Frequency Domains ◽  
Shift Keying ◽  
Modulation Methods ◽  
Binary Phase Shift Keying ◽  
Signal Time

The Enhanced Loran (eLoran) system is valued for its important role in the positioning, navigation, and timing fields; however, with its current modulation methods, low data rate restricts its development. Ultra narrow band (UNB) modulation is a modulation method with extremely high spectrum utilization. If UNB modulation can be applied to the eLoran system, it will be very helpful. The extended binary phase shift keying modulation in UNB modulation is selected for a detailed study, parameters and application model are designed according to its unique characteristics of signal time and frequency domains, and it is verified through simulation that the application of this modulation not only meets the design constraints of the eLoran system but also does not affect the reception of the respective signals of both parties. Several feasible schemes are compared, analyzed, and selected. Studies have revealed that application of UNB modulation in the eLoran system is feasible, and it will increase the data rate of the system by dozens of times.

scholarly journals Stacked Buck Converter: Current Ripple Elimination Effect and Transient Response

Energies ◽  
2020 ◽  
Vol 14 (1) ◽  
pp. 64
Author(s):  
Chien-Chun Huang ◽  
Yu-Chen Liu ◽  
Chia-Ching Lin ◽  
Chih-Yu Ni ◽  
Huang-Jen Chiu
Keyword(s):  
Transient Response ◽  
Dead Time ◽  
Control Method ◽  
Buck Converter ◽  
Modulation Method ◽  
Output Current ◽  
Time Modulation ◽  
Advantages And Disadvantages ◽  
Improvement Method ◽  
Current Ripple

To balance the cost and volume when applying a low output current ripple, the power supply design should be able to eliminate the current ripple under any duty cycle in medium and high switching frequencies, and considerably reduce filter volume to improve power density. A stacked buck converter was eventually selected after reviewing the existing solutions and discussing their advantages and disadvantages. A stacked buck converter is used as a basis to propose the transient response and output current ripple elimination effect, boundary limit control method, and low output ripple dead time modulation method to make individual improvements. The principle, mathematical derivation, small-signal model, and compensator design method of the improvement method are presented in detail. Moreover, simulation results are used to mutually verify the correctness and effectiveness of the improvement method. A stacked buck converter with 330-V input, 50-V output, and 1-kW output power was implemented to verify the effect of the low output current ripple dead time modulation. Experimental results showed that the peak-to-peak value of the output current ripple was reduced from 2.09 A to 559 mA, and the RMS value was reduced from 551 mA to 91 mA, thereby effectively improving the output current ripple.

scholarly journals Optimization of TSPWM for Common-Mode Voltage Reduction in Vehicular Electric Drive System

2021 ◽  
Vol 13 (1) ◽  
pp. 5
Author(s):  
Shang Jiang ◽  
Yuan Wang
Keyword(s):  
Electric Drive ◽  
Drive System ◽  
Modulation Method ◽  
Time Interval ◽  
Common Mode ◽  
Common Mode Voltage ◽  
Electric Drive System ◽  
The Common ◽  
Modulation Methods ◽  
Zero Voltage

Common-mode voltage can be reduced effectively by optimized modulation methods without increasing additional costs. However, the existing methods cannot satisfy the requirements of the vehicular electric-drive application. This paper optimizes the tri-state voltage modulation method to reduce the common-mode voltage for vehicular electric drive system applications. Firstly, the discontinuous switching issue during sector transition is analyzed. Under the limit of two switching times in one period, multiple alignments combination is proposed to address that issue. Secondly, the zero-voltage time intervals in different modulation ranges are explored. This paper proposes an unsymmetric translation method to reconstruct the voltage vector, and then the minimum zero-voltage time interval is controlled to enough value for safe switching. Finally, the proposed methods have been validated through experiments on a vehicular electric drive system. The results show that the common-mode voltage can be reduced effectively in the whole range with the optimized tri-state voltage modulation method.

scholarly journals NOISE STABILITY OF SIGNAL RECEPTION ALGORITHMS WITH MULTIPULSE PULSE-POSITION MODULATION

2018 ◽  
Vol 42 (1) ◽  
pp. 167-174 ◽  
Author(s):  
V. I. Parfenov ◽  
D. Y. Golovanov
Keyword(s):  
Communication Systems ◽  
Pulse Sequence ◽  
Signal To Noise Ratio ◽  
Point Of View ◽  
Estimation Accuracy ◽  
Pulse Position Modulation ◽  
Signal To Noise ◽  
Pass Filter ◽  
Low Pass Filter ◽  
Noise Ratio

An algorithm for estimating time positions and amplitudes of a periodic pulse sequence from a small number of samples was proposed. The number of these samples was determined only by the number of pulses. The performance of this algorithm was considered on the assumption that the spectrum of the original signal is limited with an ideal low-pass filter or the Nyquist filter, and conditions for the conversion from one filter to the other were determined. The efficiency of the proposed algorithm was investigated through analyzing in which way the dispersion of estimates of time positions and amplitudes depends on the signal-to-noise ratio and on the number of pulses in the sequence. It was shown that, from this point of view, the efficiency of the algorithm decreases with increasing number of sequence pulses. Besides, the efficiency of the proposed algorithm decreases with decreasing signal-to-noise ratio.It was found that, unlike the classical maximum likelihood algorithm, the proposed algorithm does not require a search for the maximum of a multivariable function, meanwhile characteristics of the estimates are practically the same for both these methods. Also, it was shown that the estimation accuracy of the proposed algorithm can be increased by an insignificant increase in the number of signal samples.The results obtained may be used in the practical design of laser communication systems, in which the multipulse pulse-position modulation is used for message transmission. 

scholarly journals BER Performance Analysis of Non-Coherent Q-Ary Pulse Position Modulation Receivers on AWGN Channel

Sensors ◽  
2021 ◽  
Vol 21 (18) ◽  
pp. 6102
Author(s):  
Xianhua Shi ◽  
Yimao Sun ◽  
Jie Tian ◽  
Maolin Chen ◽  
Youjiang Liu ◽  
...  
Keyword(s):  
Gaussian Noise ◽  
Additive White Gaussian Noise ◽  
Theoretical Formula ◽  
Pulse Position Modulation ◽  
Error Performance ◽  
Optimal Receiver ◽  
Awgn Channel ◽  
Simulation Results ◽  
The Relationship ◽  
Better Than

This paper introduces the structure of a Q-ary pulse position modulation (PPM) signal and presents a noncoherent suboptimal receiver and a noncoherent optimal receiver. Aiming at addressing the lack of an accurate theoretical formula of the bit error rate (BER) of a Q-ary PPM receiver in the additive white Gaussian noise (AWGN) channel in the existing literature, the theoretical formulas of the BER of a noncoherent suboptimal receiver and noncoherent optimal receiver are derived, respectively. The simulation results verify the correctness of the theoretical formulas. The theoretical formulas can be applied to a Q-ary PPM system including binary PPM. In addition, the analysis shows that the larger the Q, the better the error performance of the receiver and that the error performance of the optimal receiver is about 2 dB better than that of the suboptimal receiver. The relationship between the threshold coefficient of the suboptimal receiver and the error performance is also given.

scholarly journals Research and Analysis of Digital Baseband Transmission System Based on MATLAB

2018 ◽  
Vol 1 (1) ◽  
Author(s):  
Chai Jianwen
Keyword(s):  
Signal Transmission ◽  
Digital Signal ◽  
Transmission System ◽  
Simulation Software ◽  
Line Pattern ◽  
Matlab Simulation ◽  
Simulation Process ◽  
Transmission Process ◽  
Baseband Signal ◽  
Digital Baseband

This paper mainly studies the basic concept of baseband transmission of digital signal and the transmission processof digital signal baseband transmission and how to design digital baseband transmission system with MATLABsoftware simulation. This paper fi rst introduces the theoretical basis of this subject, including digital communication,the composition of digital baseband transmission system and digital baseband signal transmission process. Then thepaper introduced the characteristics of digital baseband transmission system, including digital PAM signal powerdensity and common line pattern, and by comparing choosing the fi nal bipolar zero return code. Then we introducedthe MATLAB simulation software. The conditions of the best reception of the digital baseband signal are describedand how the waveform of the baseband signal is observed by an oscilloscope. Finally, according to the basic stepsof simulation process, the simulation process of digital baseband transmission system is realized by MATLABsimulation tool, and the system is analyzed.

The Research and Performance Simulation of C-WQPSK Modulation

2012 ◽  
Vol 482-484 ◽  
pp. 771-775 ◽  
Author(s):  
Guo Hui Wu ◽  
Bao Jun Chu ◽  
Ji Yang Dai
Keyword(s):  
Power Spectrum ◽  
Engineering Application ◽  
Pulse Signal ◽  
Modulation Method ◽  
Carrier Wave ◽  
Performance Simulation ◽  
Numerical Tests ◽  
Decline Rate ◽  
And Performance ◽  
Ber Performance

By modifying the modulated waveform, a new communication modulation method, which is called C-WQPSK, is proposed in this paper. This method based on direct carrier QPSK, didn’t consider baseband pulse signal, and redesigned the modulating waveform, its phase angle jump and jump to change duration time all can be changed. Results of the numerical tests indicate that, the method is correctness and effectiveness. Compared with direct carrier QPSK, the method can keep the BER performance, meanwhile, power spectrum decline rate, the energy of modulated carrier wave, and anti-interference ability are improved and enhanced, so it owns high theory significance and engineering application value.

scholarly journals Experimental Study of a Signal Modulation Method to Improve eLORAN Data Channel Communications

Sensors ◽  
2020 ◽  
Vol 20 (22) ◽  
pp. 6504
Author(s):  
Chaozhong Yang ◽  
Yulin Wang ◽  
Shifeng Li ◽  
Wenhe Yan
Keyword(s):  
Phase Modulation ◽  
Service System ◽  
Modulation Method ◽  
Pulse Modulation ◽  
Digital Modulation ◽  
Typical Application ◽  
Time Service ◽  
Data Channel ◽  
Modulation Coding ◽  
Modulation Methods

There are mainly two types of data modulation methods used for enhanced LOng-RAnge Navigation (eLORAN) systems: pulse position modulation (PPM) and supernumerary interpulse modulation (SIM). The typical application for PPM is tri-state PPM (3S-PPM), also known as Eurofix. The typical application for SIM is ninth pulse modulation. Both of these methods are phase modulation methods. Phase modulation coding, a very mature technology, is used at present. To achieve a better demodulation success rate of eLORAN digital modulation signals at longer distances, a method of using the transmitting station duplex mode to transmit a digital modulation pulse group after LORAN-C transmitting a pulse group is proposed to realize modulation pulse on–off modulation. In this method, a broadcasting experiment was performed on the BPL (The call sign of eLORAN time service system in China) broadcaster station. After monitoring, a good receiving demodulation effect was initially obtained.

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