scholarly journals The impact of financial repression on manufacturing upgrade based on fractional Fourier transform and probability

2021 ◽  
Vol 0 (0) ◽  
Author(s):  
Na Zhao ◽  
Fengge Yao ◽  
Alaa Omar Khadidos ◽  
Bishr Muhamed Muwafak
Keyword(s):  
Fourier Transform ◽  
Fractional Fourier Transform ◽  
Average Power ◽  
Power Ratio ◽  
Informal Finance ◽  
Financial Repression ◽  
Manufacturing Enterprises ◽  
Financing Channels ◽  
The Cost ◽  
The Impact

Abstract This paper proposes a method combining fractional Fourier transform (FRFT) and a high peak-to-average power ratio suppression algorithm. Calculations show that as the order of the FRFT decreases, the peak-to-average power ratio of the signal gradually decreases; combined with the suppression algorithm can further reduce the peak-to-average power ratio of the system and solve the problem of the suppression algorithm affecting system performance. At the same time, this paper uses the 2012 World Bank survey data of Chinese manufacturing enterprises to study the influence of financial repression on the selection of financing channels of manufacturing enterprises. The research results show that financial repression has a significant impact on the choice of financing channels for manufacturing enterprises, which greatly increases the proportion of informal financial financing in the operating capital of enterprises and reduces the proportion of formal financial financing. Financial repression has led to an increase in the cost of formal financial financing, making enterprises choose informal financial channels for financing. Among them, large enterprises tend to choose commercial credit in informal finance, while small and medium-sized enterprises choose private credit It is possible to choose two financing channels, which reflects the ‘scale discrimination’ characteristics of financial repression.

scholarly journals Advantages of Spectrally Efficient Frequency Division Multiplexing Over Orthogonal Frequency Division Multiplexing

2020 ◽  
Vol 9 (8) ◽  
pp. 238-244
Keyword(s):  
Orthogonal Frequency Division Multiplexing ◽  
Average Power ◽  
Frequency Division Multiplexing ◽  
Power Ratio ◽  
Frequency Division ◽  
Sphere Decoder ◽  
Symbol Rate ◽  
Transmission Length ◽  
Spectrally Efficient ◽  
The Impact

An analysis on Spectrally Efficient Frequency Division Multiplexing (SEFDM) is contrast with Orthogonal Frequency Division Multiplexing (OFDM) considering the impact on Peak to Average Power Ratio (PAPR) and nonlinearities within fibre. With respect to OFDM the sub-carriers in SEFDM signals are compressed adjacent to each other at a rate of frequency lesser than the symbol rate. At the receiver end we have utilized the Sphere Decoder which is used to recover the data to remunerate the Interference created by the compressed signals (ICI) faced in the system. This research shows the advantages by using SEFDM and evaluates its achievement. PAPR. when compared with OFDM, while effects of non-linear fibres are considered. The use of various formats of modulation going from 4-QAM to 32-QAM, shows that the SEFDM signals have a noteworthy increment in the transmission length with respect to ordinary signals.

scholarly journals Three Term Weighted Type Fractional Fourier Transform Based Generalized Hybrid Carrier and Its Application into PAPR Suppression

2021 ◽  
Author(s):  
Yong Li ◽  
Zhiqun Song ◽  
Teng Sun ◽  
Bin Wang
Keyword(s):  
Fourier Transform ◽  
Orthogonal Frequency Division Multiplexing ◽  
Fractional Fourier Transform ◽  
Average Power ◽  
The Novel ◽  
Cumulative Density Function ◽  
Ofdm System ◽  
Single Carrier ◽  
Definition Of ◽  
Weighted Type

To suppress the peak to average power ratio (PAPR) of wireless communication based upon multi-carrier system. We, in this paper, proposed the three term weighted type fractional Fourier transform (3-WFRFT) based generalized hybrid carrier (GHC) system. We first provide the definition of 3-WFRFT. Moreover, some useful properties of 3-WFRFT have been presented, in this paper, which will helpful to comprehend the novel 3-WFRFT transform. Furthermore, we take PAPR of the proposed algorithm, in comparison with orthogonal frequency division multiplexing (OFDM) system and single carrier modulation (SC) system under typical complementary cumulative density function (CCDF) level. It would be demonstrated that, from some numerical simulations, the proposed 3-WFRFT based GHC performs better than OFDM system and will be useful to reduce the PAPR level.

scholarly journals Reducing the Cost of Implementing Filters in LoRa Devices

Sensors ◽  
2019 ◽  
Vol 19 (18) ◽  
pp. 4037
Author(s):  
Shania Stewart ◽  
Ha H. Nguyen ◽  
Robert Barton ◽  
Jerome Henry
Keyword(s):  
Fourier Transform ◽  
Fast Fourier Transform ◽  
System Performance ◽  
Pulse Shaping ◽  
Error Rates ◽  
Lookup Table ◽  
Significant Performance ◽  
High Level ◽  
The Cost ◽  
The Impact

This paper presents two methods to optimize LoRa (Low-Power Long-Range) devices so that implementing multiplier-less pulse shaping filters is more economical. Basic chirp waveforms can be generated more efficiently using the method of chirp segmentation so that only a quarter of the samples needs to be stored in the ROM. Quantization can also be applied to the basic chirp samples in order to reduce the number of unique input values to the filter, which in turn reduces the size of the lookup table for multiplier-less filter implementation. Various tests were performed on a simulated LoRa system in order to evaluate the impact of the quantization error on the system performance. By examining the occupied bandwidth, fast Fourier transform used for symbol demodulation, and bit-error rates, it is shown that even performing a high level of quantization does not cause significant performance degradation. Therefore, the memory requirements of LoRa devices can be significantly reduced by using the methods of chirp segmentation and quantization so as to improve the feasibility of implementing multiplier-less filters in LoRa devices.

scholarly journals Generalized Discrete Fourier Transform for FBMC Peak to Average Power Ratio Reduction

IEEE Access ◽  
2019 ◽  
Vol 7 ◽  
pp. 81730-81740 ◽  
Author(s):  
Mohamed A. Aboul-Dahab ◽  
Mohamed M. Fouad ◽  
Radwa A. Roshdy
Keyword(s):  
Fourier Transform ◽  
Discrete Fourier Transform ◽  
Average Power ◽  
Power Ratio ◽  
Power Ratio Reduction ◽  
Ratio Reduction

scholarly journals Peak to Average Power Ratio Reduction in NC–OFDM Systems

2015 ◽  
Vol 66 (3) ◽  
pp. 154-158 ◽  
Author(s):  
Saadia Tabassum ◽  
Sajjad Hussain ◽  
Abdul Ghafoor
Keyword(s):  
Orthogonal Frequency Division Multiplexing ◽  
Fractional Fourier Transform ◽  
Average Power ◽  
Modulation Scheme ◽  
Power Ratio ◽  
Ofdm Systems ◽  
Radio Communications ◽  
Trigonometric Transforms ◽  
Power Ratio Reduction ◽  
Ratio Reduction

Abstract Non contiguous orthogonal frequency division multiplexing (NC-OFDM) is an efficient and adaptable multicarrier modulation scheme to be used in cognitive radio communications. However like OFDM, NC-OFDM also suffers from the main drawback of high peak to average power ratio (PAPR). In this paper PAPR has been reduced by employing three different trigonometric transforms. Discrete cosine transform (DCT), discrete sine transform (DST) and fractional fourier transform (FRFT) has been combined with conventional selected level mapping (SLM) technique to reduce the PAPR of both OFDM and NC-OFDM based systems. The method combines all the transforms with SLM in different ways. Transforms DCT, DST and FRFT have been applied before the SLM block or inside the SLM block before IFFT. Simulation results show the comparative analysis of all the transforms using SLM in case of both OFDM and NC-OFDM based systems.

scholarly journals Investigating the Impact of Power-Take-Off System Parameters and Control Law on a Rotational Wave Energy Converter’s Peak-to-Average Power Ratio Reduction

2020 ◽  
Author(s):  
H. Bora Karayaka ◽  
Yi-Hsiang Yu ◽  
Nathan Tom ◽  
Eduard Muljadi
Keyword(s):  
Wave Energy ◽  
High Speed ◽  
High Efficiency ◽  
Average Power ◽  
Gear Ratio ◽  
Irregular Waves ◽  
Strong Impact ◽  
Power Ratio ◽  
Hardware In The Loop ◽  
The Impact

Abstract Due to the irregular nature of real waves, the power captured in a wave energy converter (WEC) system is highly variable. This is an important barrier to the effective use of WECs. To address this challenge, this study focuses on a rotational WEC power-take-off system in which high-speed and high-efficiency generators along with a torque/power smoothing inertia element can be effectively utilized. In the first phase of this study, the U.S. Department of Energy’s reference model 3 (WEC-Sim RM3; two-body point absorber), along with a slider-crank WEC, were integrated for linear to rotational conversion. Relative motion between the float and spar in RM3 was the driving force for this slider-crank WEC, which is connected to a motor/generator set through a gearbox. RM3 geometry was scaled down by 25 times to work within the limits of the physical motor/generator set used in the experimentation. Once the integration in a hardware-in-the-loop simulation environment was successfully completed, data on the peak-to-average power ratio was collected for various wave conditions including regular and irregular waves. The control algorithm designed to keep the system in resonance with waves was able to maintain relatively high speed depending on the specific gear ratio and wave period. Initial results with hardware-in-the-loop simulations reveal that gear ratio and crank radius have a strong impact on the peak-to-average power ratio. In addition, it was found that output power from the generator was maximized at a larger gear ratio, as the crank radius was increased.

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