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Decision-feedback multiple symbol detection for differential space-time block coded UWB systems

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Science China(Information Sciences) 2013年第4期56卷 50-59页

作者： LV TieJun WANG TaoTao GAO Hui Key Laboratory of Trustworthy Distributed Computing and Service Ministry of EducationBeijing University of Posts and Telecommunications Department of Information Engineering The Chinese University of Hong Kong

The symbol-by-symbol differential detection scheme,originally employed to detect differential spacetime block coded(DSTBC) ultra-wideband(UWB) signal in previous work,su?ers from a performance degradation compared with coherent *** this paper,a noncoherent multiple symbol detection(MSD) scheme is proposed to enhance the performance of DSTBC-UWB *** the signal model of DSTBC-UWB is analyzed,the optimal maximum likelihood(ML) MSD is derived and then a suboptimal ML-MSD is obtained by channel ***,exhaustive search based MSD is impractical in DSTBC-UWB systems since its complexity increases exponentially with observation window *** decrease the computational complexity,the decision-feedback(DF) scheme is introduced to *** resultant DF-MSD yields reasonable complexity and solid performance improvement.

关键词： ultra-wideband(UWB) space-time block code(STBC) differential detection multiple symbol detection(MSD)

EM-based detection scheme for differential unitary space-time modulation

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Journal of Southeast University(English Edition) 2007年第4期23卷 484-488页

作者：杜正锋陈杰潘文高西奇东南大学移动通信国家重点实验室南京210096

The performance loss of an approximately 3 dB signal-to-noise ratio is always paid with conventional differential detection compared to the related coherent detection. A new detection scheme consisting of two steps is proposed for the differential unitary space-time modulation （DUSTM） system. In the first step, the data sequence is estimated by conventional unitary space-time demodulation （DUSTD） and differentially encoded again to produce an initial estimate of the transmitted symbol stream. In the second step, the initial estimate of the symbol stream is utilized to initialize an expectation maximization （EM）-based iterative detector. In each iteration, the most recent detected symbol stream is employed to estimate the channel, which is then used to implement coherent sequence detection to refine the symbol stream. Simulation results show that the proposed detection scheme performs much better than the conventional DUSTD after several iterations.

关键词： unitary space-time modulation differential detection expectation maximization (EM) algorithm

Application of transmit diversity for improved robust watermarking

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Journal of Systems Engineering and Electronics 2004年第2期15卷 163-170页

作者： SunRui SunHong YaoTianren DepartmentofElectronicandInformationEngineering HuazhongUniversityofScienceandTechnologyWuhan430074P.R.China DepartmentofCommunicationEngineering WuhanUniversityWuhan430072P.R.China

Many common multimedia signal processing, including cropping, filtering, and perceptual coding, make watermark signal fading-like modification. A scheme that applies transmit diversity technique to improve robustness of digital watermarking is presented. First, the scheme decomposes the original image using wavelet pyramid algorithm and chooses the middle-frequency band for transmission channel that the watermark will be embedded into. Then the watermark is pseudo-randomly permuted. The scheme makes use of space-time coding and differential detection technique to embed and extract watermark. The extracting process has access to neither the original image nor channel state information. Experimental results demonstrate that the scheme improves the performance of robust watermarking.

关键词： digital watermark transmit diversity space-time coding differential detection wavelet transform.

BER ANALYSIS OF A GMSK SYSTEM USING DECISION FEEDBACK

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Journal of Electronics(China) 2008年第4期25卷 544-551页

作者： He Xiandeng Pei Changxing The State Key Lab of Integrated Services Networks Xidian University Xi＇an 710071 China

There are considerable literatures on the Bit Error Rate(BER)evaluation of differentialdetection of Gaussian Minimum Shift Keying(DDGMSK)system using Decision Feedback(DF),butmost of them give the performance based on the Monte Carlo Error Counting(MCEC)*** probability distribution of the phase angle between two vectors perturbed by Gaussian noises,theformulae of BER are derived for the performance analysis of DDGMSK system with DF in this *** the m-bit dock-tailed sequence,the new formulae of Gaussian Minimum Shift Keying(GMSK)modulated phase and the Time-Varying Signal to Noise Ratio(TVSNR)of the demodulatedsignal are presented,and it is proved that the relationship between the TVSNR of the demodulatedsignal and the size of eye opening is not *** results show that the theoretical in-vestigation gives analogous results with the MCEC *** formulae presented are useful for theperformance analysis of systems using GMSK as modulating and demodulating method,for instance,the analysis of synchronous performance of frequency-hopping communication system.

关键词： Gaussian Minimum Shift Keying (GMSK) differential detection Decision Feedback (DF) Bit Error Rate (BER)

Performance of the Combining Received differential Encoding Transmit Diversity with Imperfect Carrier Recovery over Correlated Nakagami Fading Channels

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Performance of the Combining Received Differential Encoding ...

Design of a Weak Signal Detecting Circuit in the Infrared Spectrum Absorbed Type Gas Sensor

2003 International Conference on Communication Technology

作者： Guoping FAN Pingyi FAN and Zhigang CAO Department of Electronic Engineering Tsinghua University Beijing 100084

A differential detection scheme for transmit diversity was proposed by Tarokh in [1], which can achieve full diversity order without the requirement to estimate the channel state at the receiver. This

关键词： transmit diversity differential detection carrier recovery bit error rate wireless communications

来源： cnki会议评论

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Journal of Measurement Science and Instrumentation 2011年第4期2卷 384-386页

作者：李小平周佩丽 School of Electronic and Information Engineering Beihang University Beijing 100191 China Engineering Technology Research Center of Shanxi Province for Opto-Electronic Information and Instrument North University of China Taiyuan 030051 China

In the infrared spectrum absorbed type gas concentration sensor,voltage signal obtained from the two-channel thermopile infrared detector TPS2534 is very *** order to solve this problem,the authors have established the structure of the sensor and designed weak signal detecting circuit of the sensor based on infrared spectrum absorption principle,differential de-noising principle and weak signal detecting *** authors have made experiments using CH4 *** results show that the circuit can remove noise effectively and detect weak electrical signal obtained from the detector.

关键词： IR spectrum absorption differential detection weak signal