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Zhang L.,Yantai Naval Aeronautical and Astronautical University | Chen Z.,Yantai Naval Aeronautical and Astronautical University | Wang H.,Yantai Naval Aeronautical and Astronautical University | Wang H.,Key Laboratory on Signal and Information Processing of Shandong Province | And 2 more authors.
Dianbo Kexue Xuebao/Chinese Journal of Radio Science | Year: 2013

A decorrelation method of whiting transform based on successive inter-ference cancellation (SIC) is proposed for improving the performance of demodulation of the non-sinusoidal orthogonal modulation system in time domain. The simulations demonstrate that the performance of the proposed method is better, especially when pulses have different amplitudes. Copyright © 2013 by Editorial Department of Chinese Journal of Radio Science.


Kang J.-F.,Chinese Naval Aeronautical Engineering Academy | Wang H.-X.,Chinese Naval Aeronautical Engineering Academy | Wang H.-X.,Key Laboratory on Signal and Information Processing of Shandong Province | Zhao Z.-Y.,Chinese Naval Aeronautical Engineering Academy | And 3 more authors.
Tongxin Xuebao/Journal on Communications | Year: 2013

As the bandwidth efficiency of traditional spread spectrum modulation is quite low, a novel spread spectrum communication method, which uses the relative position of the spread spectrum modulation symbol to carry information was presented, and the method establishes the relationship between the information transfer rate and the spreading code or the transmission bandwidth. Theoretical analysis and simulation results show that the modulation method can not only greatly improve the bandwidth efficiency of the spread spectrum system, but also effectively combat broadband, narrowband or other spread spectrum interference. This method provides some novel ideas for the future research of spread spectrum communications.


Liu C.-H.,Yantai Naval Aeronautical and Astronautical University | Wang H.-X.,Yantai Naval Aeronautical and Astronautical University | Wang H.-X.,Key Laboratory on Signal and Information Processing of Shandong Province | Zhang L.,Yantai Naval Aeronautical and Astronautical University | Liu X.-G.,Yantai Naval Aeronautical and Astronautical University
Yingyong Kexue Xuebao/Journal of Applied Sciences | Year: 2013

To get higher accuracy of prolate spheroidal wave function (PSWF) pulse generator and reduce quantization bits, quantization error in the traditional PSWF generator based on direct digital waveform synthesis (DDWS) is analyzed. The main factors that affect quantization accuracy are listed. A design method for PSWF pulse generator based on difference quantitation is proposed. The method uses difference quantitation rather than direct quantization and modifies the DAC module. Theoretical analysis and simulation show that, as the over sampling rate (OSR) is greater than p, difference quantitation can improve the noise spectrum. When OSR is doubled, the noise spectrum is improved by 6 dB, as compared to 3 dB of direct quantitation. The difference quantitation method has higher quantitation accuracy with the same or even less number of quantitation bits. Therefore, PSWF pulse generator based on the difference quantitation is more suitable for high-precision PSWF signal generation with high sampling rate.


Kang J.,Chinese Naval Aeronautical Engineering Academy | Wang H.,Chinese Naval Aeronautical Engineering Academy | Wang H.,Key Laboratory on Signal and Information Processing of Shandong Province | Zhong P.,Chinese Naval Aeronautical Engineering Academy | And 2 more authors.
2014 31th URSI General Assembly and Scientific Symposium, URSI GASS 2014 | Year: 2014

Based on the symmetry characteristic of subcarriers in the traditional orthogonal frequency division multiplexing (OFDM) system, we propose a half symbol OFDM (HS-OFDM) modulation method to further improve the bandwidth efficiency of communication system, the method applicable to OFDM systems whose subcarriers are modulated by BPSK or PAM. The spectra overlap percentage of adjacent subcarriers is raised from 50% to 75%, and the bandwidth efficiency upper limit of the passband OFDM system is raised from 1Baud/Hz to 2Baud/Hz, which is twice the efficiency of the traditional OFDM system. © 2014 IEEE.


Liu M.,Yantai University | Liu M.,Key Laboratory on Signal and Information Processing of Shandong Province | Wang H.,Yantai University | Wang H.,Key Laboratory on Signal and Information Processing of Shandong Province | And 4 more authors.
Zhongguo Jiguang/Chinese Journal of Lasers | Year: 2011

For the problem of the big errors in the calculation of atmospheric attenuation under water fog weather, starting from the physical phenomena of water fogs weather, through the revision of the existing model, a more precise and reasonable model was proposed. And using the proposed model, the performance of free space optical (FSO) communication system was analyzed, the simulated results pointed out that the relative errors caused by the existing model can't be ignored. The work can provide a theoretical basis for the evaluation and estimation of FSO communication system and other related domain in water fogs weather.

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