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

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.

2011 ◽  
Vol 403-408 ◽  
pp. 2547-2551
Author(s):  
Zhan Hui Cai ◽  
Yuan Cheng Yao

Automatic modulation classification plays a significant role in intelligent communication. A new method based on feature extraction is proposed for the recognition of M-ary Phase Shift Keying (MPSK) signals. As features, fourth and eighth order cumulants of the input samples and phase differential sequences were applied. It is shown that the cumulant-based features have robust anti-noise ability. Simulation results demonstrate that the correct classification probability (Pcc) with the proposed algorithm is higher than the existing approaches at low signal-to-noise ratio (SNR).


2019 ◽  
Vol 0 (0) ◽  
Author(s):  
Bahman Shahmohammadi ◽  
Alireza Andalib

AbstractIn this paper, we are going to design simulate an all optical OR gate based on two-dimensional photonic crystals. The proposed structure was designed based on phase shift keying technique. The working principle of the proposed structure is based on constructive and destructive interference of optical beams. The simulation results shows that the rise and fall times are 0.8 and 0.2 ps, respectively.


Electronics ◽  
2020 ◽  
Vol 9 (12) ◽  
pp. 2049
Author(s):  
Congyu Shi ◽  
Gaoyuan Zhang ◽  
Haiqiong Li ◽  
Congzheng Han ◽  
Jie Tang ◽  
...  

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.


2014 ◽  
Vol 2014 ◽  
pp. 1-9 ◽  
Author(s):  
Yidong Xu ◽  
Wei Xue ◽  
Wenjing Shang

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.


2014 ◽  
Vol 644-650 ◽  
pp. 4439-4442
Author(s):  
Yan Jun Wu ◽  
Gang Fu ◽  
Peng Yu

Presented to the π / 4 differential quaternary phase shift keying signal (π/4-DQPSK) using the discrete Fourier transform (DFT) for software demodulation algorithm in consideration of the actual received waveform into transition to π/4-DQPSK District and stable region, and only the waveform sampling point DFT transform the region stable recovery decision. simulation gives the demodulation method to achieve the same differential demodulation relatively simple structure, and the anti-noise in the signal to noise ratio greater than 3dB better performance than the differential demodulation performance, expected the algorithm is applied π/4-DQPSK software radio receiver design.


Sensors ◽  
2019 ◽  
Vol 19 (8) ◽  
pp. 1938 ◽  
Author(s):  
Haiyuan Wang ◽  
Hongxian Tian

Low-Power Wide-Area Network (LPWAN) is the technology that the Internet-of-Things (IoT) uses in long-distance, wide-coverage scenarios. As one of the ultra-narrowband (UNB) modulation techniques, M-ary position phase shift keying (MPPSK) modulation can provide high coverage and high reliability for LPWAN. This paper proposes a multipath separation method based on MPPSK modulation, which aims to eliminate the influence of multipath on the main path without increasing the spectrum overhead and system complexity. Specifically, the modulation parameter of the system is adjusted according to the delay value, so that the phase jump of the multipath signal falls outside the phase jump of the main path symbol to achieve separation of the multipath from the main path. Moreover, a normalized symbol joint decision method is proposed in order to reduce the introduced noise while using multipath information for decisions. The simulation results indicate that the multipath separation conditions given in this paper can meet the requirements of multipath separation of MPPSK signals. Compared with the existing mainstream decision scheme, the normalized symbol joint decision improves the demodulation performance of the system.


2013 ◽  
Vol 694-697 ◽  
pp. 2870-2873
Author(s):  
Dong Ming Lei ◽  
Ping Li ◽  
Nian Yu Zou

Based on the traditional demodulation method of four phase shift keying (QPSK), a QPSK demodulation model was proposed. The FPGA-based QPSK modulation and demodulation system and circuit had been achieved. In Xilinx ISE12.3 development environment, using the SPARTAN-3E development board, the simulation results demonstrate the feasibility of this design.


2016 ◽  
Vol 3 (1) ◽  
pp. 1-6
Author(s):  
Ahmat Sobri ◽  
Irwan Dinata ◽  
Rudy Kurniawan

Sistem Asymmetric Digital Subscriber Line (ADSL) merupakan teknologi akses yang memungkinkan terjadinya komunikasi data, suara dan video secara bersamaan pada media akses tembaga. Komunikasi data tidak dapat dihindarkan dari adanya derau, tidak terkecuali sistem ADSL yang mengalami kesalahan dalam hal pengiriman yang disebabkan adanya derau sehingga membuat nilai bit error rate (BER) meningkat. Oleh karena itu, diperlukan cara untuk mengurangi derau sehingga dapat memperkecil nilai BER. Untuk mengurangi derau dan mendapatkan nilai BER maka diperlukan metode modulasi Quadrature phase shift keying (QPSK) pada sistem ADSL. Visualisasi sistem dibutuhkan untuk mengetahui kinerja dari sistem ADSL dan mengetahui BER yang di timbulkan. Dari hasil visualisasi dengan memberikan masukan data 64 bit, menampilkan konstelasi yang mengalami penyebaran data tetapi tidak merusak bentuk dari konstelasi. Ketika konstelasi masuk ke kanal Additif White Gaussian Noise (AWGN) dengan simpangan antara 0 dB – 20 dB dan interval 2 dB, dihasilkan nilai BER 0.3906 pada saat Signal to Noise Ratio (SNR) bernilai 0 dB sampai akhirnya BER bernilai nol pada saat SNR berkisar antara 9 dB - 20 dB.


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