scholarly journals A Pan-Function Model for the Utilization of Bandwidth Improvement and PAPR Reduction

2014 ◽  
Vol 2014 ◽  
pp. 1-9 ◽  
Author(s):  
Yidong Xu ◽  
Wei Xue ◽  
Wenjing Shang
Keyword(s):  
Attenuation Factor ◽  
Average Power ◽  
Quadrature Modulation ◽  
Phase Shift Keying ◽  
Function Model ◽  
System A ◽  
Constant Envelope ◽  
Quadrature Phase ◽  
Shift Keying ◽  
Simulation Results

Aiming at the digital quadrature modulation system, a mathematical Pan-function model of the optimized baseband symbol signals with a symbol length of4Twas established in accordance with the minimum out-band energy radiation criterion. The intersymbol interference (ISI), symbol-correlated characteristics, and attenuation factor were introduced to establish the mathematical Pan-function model. The Pan-function was added to the constraints of boundary conditions, energy of a single baseband symbol signal, and constant-envelope conditions. Baseband symbol signals with the optimum efficient spectrum were obtained by introducing Fourier series and minimizing the Pan-function. The characteristics of the spectrum and peak-to-average power ratio (PAPR) of the obtained signals were analyzed and compared with the minimum shift keying (MSK) and quadrature phase-shift keying (QPSK) signals. The obtained signals have the characteristics of a higher spectral roll-off rate, less out-band radiation, and quasi-constant envelope. We simulated the performance of the obtained signals, and the simulation results demonstrate that the method is feasible.

Reduction of PAPR in FBMC System Using Different Reduction Techniques

2018 ◽  
Vol 0 (0) ◽  
Author(s):  
Arun Kumar ◽  
Hemant Rathore
Keyword(s):  
Phase Shift ◽  
Research Study ◽  
Average Power ◽  
Phase Shift Keying ◽  
Reduction Techniques ◽  
Quadrature Phase Shift Keying ◽  
Quadrature Phase ◽  
Shift Keying ◽  
Clipping Technique ◽  
Binary Phase Shift Keying

AbstractIn this research study, different Peak Average Power Ratio (PAPR) based reduction techniques, namely, A-Law companding, µ-Law companding, Clipping & Filtering and Clipping are analyzed for Filter Band Multi-Carrier (FBMC) with different transmission systems such as Binary Phase Shift Keying (BPSK), Quadrature Phase Shift Keying (QPSK), 64-QPSK and 64-Quadrature Amplitude Modulation. It is estimated that the PAPR reduction can benefit by using clipping technique in FBMC.

scholarly journals Reduced-Complexity Multiple-Symbol Detection of O-QPSK Signals in Smart Metering Utility Networks

Electronics ◽  
2020 ◽  
Vol 9 (12) ◽  
pp. 2049
Author(s):  
Congyu Shi ◽  
Gaoyuan Zhang ◽  
Haiqiong Li ◽  
Congzheng Han ◽  
Jie Tang ◽  
...  
Keyword(s):  
Detection Performance ◽  
Smart Metering ◽  
Phase Shift Keying ◽  
High Complexity ◽  
Observation Window ◽  
Slow Fading ◽  
Symbol Detection ◽  
Quadrature Phase ◽  
Shift Keying ◽  
Simulation Results

In this work, an implementation-friendly multiple-symbol detection (MSD) scheme is proposed for the IEEE 802.15.4g offset quadrature phase shift keying (O-QPSK) receivers over the slow fading channel. The full MSD scheme presents better detection performance than the symbol-by-symbol detection (SBSD) scheme, yet its complexity increases exponentially as the observation window length increases. We introduce a simplified MSD scheme based on two powerful strategies. We first seek the optimal and suboptimal decisions in each symbol position with the standard SBSD procedure. Then, the aforementioned optimal and suboptimal decisions instead of all candidates are jointly searched with the standard MSD procedure. That is, only the most and second most reliable candidates in each symbol position are selected to participate in the final detection. The simulation results demonstrate that the new MSD scheme can achieve more encouraging energy gain than the SBSD scheme, while the high complexity of full MSD is also effectively reduced. A more legitimate compromise between detection performance and complexity is thus accomplished, which enables smart metering utility networks (SUN) nodes to achieve energy saving and maximum service life.

scholarly journals A Reduction of Peak-to-Average Power Ratio Based Faster-Than-Nyquist Quadrature Signals for Satellite Communication

Symmetry ◽  
2021 ◽  
Vol 13 (2) ◽  
pp. 346
Author(s):  
Sergey B. Makarov ◽  
Mingxin Liu ◽  
Anna S. Ovsyannikova ◽  
Sergey V. Zavjalov ◽  
ILya Lavrenyuk ◽  
...  
Keyword(s):  
Phase Shift ◽  
Satellite Communication ◽  
Average Power ◽  
Reduction Rate ◽  
Digital Television ◽  
Power Ratio ◽  
Phase Shift Keying ◽  
Quadrature Phase Shift Keying ◽  
Quadrature Phase ◽  
Shift Keying

The increase in the throughput of digital television and radio broadcasting (DVB) channels can be achieved due to application of signals with a compact spectrum and a relatively small peak-to-average power ratio (PAPR). The reason is the usage of traveling wave tubes (TWT) for amplifying and transmitting signals from a satellite repeater in DVB-S2X systems. At the same time, given that the bandwidth allocated for transmission should be used as efficiently as possible, a high reduction rate of out-of-band emissions level is required. The most effective solution in this direction is the transition to spectrum-economic signals, such as optimal Faster-Than-Nyquist (FTN) signals, which can provide a certain reduction rate of the out-of-band emissions level and minimum acceptable PAPR. This article proposes a method for obtaining optimal FTN pulses, which have symmetry in time domain, with specified PAPR and reduction rate of out-of-band emissions for the quadrature phase shift keying (QPSK) and offset quadrature phase shift keying (OQPSK). The possibility of synthesizing signals with OQPSK modulation is presented theoretically for the first time. Optimal FTN signals can provide PAPR reduction by at most 3 dB and outperform known root raised cosine (RRC) pulses. The simulation model adopts an architecture for quadrature generation of optimal FTN signals with OQPSK modulation with blocks for adjustable pre-amplification, clipping, and power amplification. The proposed signals can be used to increase the spectral and energy efficiencies of satellite broadcasting systems, such as DVB-S2/S2X, as well as low-rate return channels of interactive broadcasting systems with a frequency resource shortage.

scholarly journals Analysis and Compensation of Chromatic Dispersion in Long-hauls Optical Coherent System

2021 ◽  
Author(s):  
Narimane Hadjadji ◽  
Rachid Hamdi
Keyword(s):  
Dispersion Compensation ◽  
Chromatic Dispersion ◽  
Optical Systems ◽  
Coherent System ◽  
Phase Shift Keying ◽  
Transmission Distance ◽  
Quadrature Phase ◽  
Shift Keying ◽  
Simulation Results ◽  
Electronic Dispersion

In this paper, we demonstrate the efficiency of Electronic Dispersion Compensation (EDC) for coherent optical systems based on Polarization Division Multiplexed Quadrature Phase Shift Keying (PDM-QPSK). The performance of the proposed system is tested using a pulse that has been recently used in the presence of nonlinear effects.The proposed system is compared to the 0.3RZ-PDM-QPSK system at the optimum launched power under different symbol-rates and lengths of transmission. The simulation results confirm that the proposed method enhances the system performance. In addition, it secures a low penalty that is below 0.6 dB. As a result, the feasible transmission distance is improved by 29 %, 20.15 %, and 26.7 %, at 14 GBaud, 28 Gbaud, and 56 Gbaud, respectively.

scholarly journals An Accurate Modulation Recognition Method of QPSK Signal

2015 ◽  
Vol 2015 ◽  
pp. 1-7 ◽  
Author(s):  
Yongxin Feng ◽  
Zhenyu Teng ◽  
Fanwei Meng ◽  
Bo Qian
Keyword(s):  
Communication Systems ◽  
Signal Classification ◽  
Signal Recognition ◽  
Phase Shift Keying ◽  
Modulation Recognition ◽  
Recognition Method ◽  
Space Condition ◽  
Quadrature Phase ◽  
Shift Keying ◽  
Simulation Results

Quadrature phase shift keying (QPSK) modulation has been widely applied in communication systems. With the increasing development of QPSK modulation recognition, it is meaningful for ensuring validity and accuracy of recognition method. Therefore, the method of signal recognition has been presented based on the features of QPSK modulated signal, in which the feature parameters of QPSK signal are extracted. Besides, signal classification is fulfilled through thresholds, and modulation recognition is completed with quartic spectrum. The simulation results show that, the method can recognize QPSK modulation effectively in less sample space condition and can be more accurate.

A Novel Symbol Rate Estimation Algorithm for Phase Modulating Signals in Wireless Communications

2013 ◽  
Vol 443 ◽  
pp. 392-396
Author(s):  
Peng Zhou ◽  
Chi Sheng Li
Keyword(s):  
Signal To Noise Ratio ◽  
Estimation Algorithm ◽  
Frequency Resolution ◽  
Phase Shift Keying ◽  
Phase Jump ◽  
Rate Estimation ◽  
Awgn Channel ◽  
Symbol Rate ◽  
Shift Keying ◽  
Simulation Results

In this paper, we proposed a new symbol rate estimation algorithm for phase shift keying (PSK) and qua drawtube amplitude modulation (QAM) signals in AWGN channel First we constructe a delay-multiplied signal, from which we obtaine the modulated information. Then we calculated the instantaneous autocorrelation of the delay-multiplied signal to pick out the phase jump. To eliminate the restriction of frequency resolution in fast Fourier transform, we performed a Chirp-Z transform to find out the exact spectral line which represente the symbol rate of the signal to be analyzed. Compared with the existing algorithms, it is a simple solution that has a better performance and accuracy in low signal-to-noise-ratio channel conditions. Simulation results show that the probability of relative estimating deviation below 0.1% reaches 100% and the average and standard variance of absolute estimation deviation are at the magnitude of 10-2 when SNR is over 2dB.

scholarly journals Research on single carrier frequency domain equalization system based on FQPSK modulation

2018 ◽  
Vol 17 ◽  
pp. 03012
Author(s):  
Meng Zhang ◽  
Zhisong Bie
Keyword(s):  
Frequency Domain ◽  
Carrier Frequency ◽  
Viterbi Algorithm ◽  
Cyclic Prefix ◽  
Phase Shift Keying ◽  
Frequency Domain Equalization ◽  
Single Carrier ◽  
High Power Amplifier ◽  
Quadrature Phase ◽  
Shift Keying

Feher-patented quadrature phase shift keying (fqpsk) modulation is proposed for single-carrier frequency domain equalization (sc-fde). this paper puts forward a new method modulation called cc-bcd-fqpsk. the fqpsk signal is oversampled to make that the discrete fourier transform (dft)/ inverse dft (idft) processing of it can be applied for sc-fde. the methodology for maintaining waveform continuity with a cyclic prefix (cp) is presented. wrap-around viterbi algorithm (wava) is suggested for demodulation after equalization at the receiver. simulation results show that sc-fde system based on cc-bcd-fqpsk modulation has higher spectral efficiency than linear modulation qpsk and is an effective approach for eliminating isi and using nonlinear high power amplifier.

Sign in / Sign up

Export Citation Format

Share Document