A Simple and useful decision feedback equalizer used for non-linear channels with severe linear distortion and mild non-linear distortion is proposed. It is a combination of a nonlinear channel equalizer based on conn...A Simple and useful decision feedback equalizer used for non-linear channels with severe linear distortion and mild non-linear distortion is proposed. It is a combination of a nonlinear channel equalizer based on connectionist model and a common decision feedback equalizer for linear channels. For a typical non-linear channel model it is shown that the equalization performances of the proposed equalizer are improved significantly.展开更多
An adaptive support vector machine decision feedback equalizer（ASVM-DFE） based on the least square support vector machine（LS-SVM） is proposed,it solves linear system iteratively with less computational intensity.A...An adaptive support vector machine decision feedback equalizer（ASVM-DFE） based on the least square support vector machine（LS-SVM） is proposed,it solves linear system iteratively with less computational intensity.An adaptive non-singleton fuzzy support vector machine decision feedback equalizer（ANSFSVMDFE） is also presented,it adopts the non-singleton fuzzy Gaussian kernel function with similar characteristic of pre-filter and is modified with a space transformation based approach.Simulations under nonlinear time variant channels show that ASVM-DFE and ANSFSVM-DFE perform very well on nonlinear equalization and ANSFSVM-DFE acts especially well in resisting abrupt interference.展开更多
A new equalization method is proposed in this paper for severely nonlinear distorted channels. The structure of decision feedback is adopted for the non-singleton fuzzy regular neural network that is trained by gradie...A new equalization method is proposed in this paper for severely nonlinear distorted channels. The structure of decision feedback is adopted for the non-singleton fuzzy regular neural network that is trained by gradient-descent algorithm. The model shows a much better performance on anti-jamming and nonlinear classification, and simulation is carried out to compare this method with other nonlinear channel equalization methods. The results show the method has the least bit error rate （BER）.展开更多
Least mean square (LMS) decision feedback equalizer (DFE) is preferred as an effective solution to coping with inter-symbol interference (ISI) for ATSC digital television (DTV) receivers. In DTV transmission environme...Least mean square (LMS) decision feedback equalizer (DFE) is preferred as an effective solution to coping with inter-symbol interference (ISI) for ATSC digital television (DTV) receivers. In DTV transmission environment, echo delay often covers several hundreds symbols, which leads to very large-scale equalizer. One consequence of the large-scale equalizer is the very slow convergence, which combined with error propagation, inherent drawback of DFE, seriously deteriorates the performance of the receivers, especially in severe channels More working modes and corresponding robust control mechanism were given to help the equalizer converge to the stable state smoothly. Simulation results show that the improved equalizer can perform better, especially in the severe channels.展开更多
A 6.25 Gbps SerDes core used in the high speed backplane communication receiver has been designedbased on the OIF-CEI-02.0 standard. To counteract the serious Inter-Symbol-Interference (ISI),the core employed a half-r...A 6.25 Gbps SerDes core used in the high speed backplane communication receiver has been designedbased on the OIF-CEI-02.0 standard. To counteract the serious Inter-Symbol-Interference (ISI),the core employed a half-rate four-tap decision feedback equalizer (DFE). The equalizer used the Sign-signleast mean-squared (SS-LMS) algorithm to realize the coefficient adaptation. An automatic gain control(AGC) amplifier with the sign least mean-squared (S-LMS) algorithm has been used to compensatethe transmission media loss. To recover the clock signal from the input data serial and provide for theDFE and AGC, a bang-bang clock recovery (BB-CR) is adopted. A third order phase loop lock (PLL)model was proposed to predict characteristics of the BB-CR. The core has been verified by behavioralmodeling in MATLAB. The results indicate that the core can meet the specifications of the backplane receiver.The DFE recovered data over a 34' FR-4 backplane has a peak-to-peak jitter of 17 ps, a horizontaleye opening of 0.87 UI, and a vertical eye opening of 500 mVpp.展开更多
We propose a trellis-compressed maximum likelihood sequence estimation(TC-MLSE)-assisted sliding-block decision feedback equalizer(DFE)to suppress the error propagation resulting from the DFE in high-speed systems.We ...We propose a trellis-compressed maximum likelihood sequence estimation(TC-MLSE)-assisted sliding-block decision feedback equalizer(DFE)to suppress the error propagation resulting from the DFE in high-speed systems.We use an out-ofrange detector to detect the end of burst errors from the DFE and activate the optional TC-MLSE to correct burst errors.We conduct experiments to transmit a 201-Gbit/s PAM-8 signal.The results show that the proposed method achieves a bit error rate of 3.65×10^(-3),which is close to that of MLSE.The optional MLSE is only activated when needed and processes 11.4%of the total symbols.Moreover,the proposed method compresses the maximum length of burst errors from 19 to 5.展开更多
In this paper,an efficient Cyclic Prefix (CP) reconstruction scheme is proposed for Sin-gle-Carrier systems with Frequency-Domain Equalization (SC-FDE) that employ insufficient length of CP at the transmitter. By util...In this paper,an efficient Cyclic Prefix (CP) reconstruction scheme is proposed for Sin-gle-Carrier systems with Frequency-Domain Equalization (SC-FDE) that employ insufficient length of CP at the transmitter. By utilizing a decision feedback filter to cancel the residual InterSymbol In-terference (ISI) in the equalized signal,the proposed scheme can effectively lower the low bound of performance for the CP reconstruction schemes and can greatly improve the Bit Error Rate (BER) performance of SC-FDE systems. In addition,the existing methods and the proposed scheme are also optimized. It is shown in the simulation results that,when the Signal-to-Noise Ratio (SNR) exceeds a certain threshold,the proposed scheme can achieve the low bound of performance for the existing methods. Moreover,by increasing the number of iteration or through optimization,the low bound can be outperformed.展开更多
This paper presents a 10Gb/s high-speed equalizer as the front-end of a receiver for backplane communication.The equalizer combines an analog equalizer and a two-tap decision-feedback equalizer in a half-rate structur...This paper presents a 10Gb/s high-speed equalizer as the front-end of a receiver for backplane communication.The equalizer combines an analog equalizer and a two-tap decision-feedback equalizer in a half-rate structure to reduce the inter-symbol-interference(ISI) of the communication channel.By employing inductive peaking technique for the high-frequency boost circuit,the bandwidth and the boost of the analog equalizer are improved.The decision-feedback equalizer optimizes the size of the CML-based circuit such as D flip-flops(DFF) and multiplex(MUX),shortening the feedback path delay and speeding up the operation considerably.Designed in the 0.18μm CMOS technology,the equalizer delivers 10Gb/s data over 18-in FR4 trace with 28-dB loss while drawing27-mW from a 1.8-V supply.The overall chip area including pads is 0.6×0.7mm^2.展开更多
In digital radio communication, diversity reception can combat flat fadingand adaptive equalization can combat Inter-Symbol Interference (ISI). In this paper, the structureand algorithm of a multi-channel equalizer wi...In digital radio communication, diversity reception can combat flat fadingand adaptive equalization can combat Inter-Symbol Interference (ISI). In this paper, the structureand algorithm of a multi-channel equalizer with combined diversity reception and adaptiveequalization techniques are studied. Because Phase-Looked-Loops (PLL) are embedded in the equalizer,this equalizer is suitable for coherent communication in channels with high phase fluctuation.Monte Carlo simulation is used to test its performance and the results show that a multi-channeldecision-feedback-equalizer has better performance than a single-channeldecision-feedback-equalizer, and the results of processing high-speed digital underwatercommunication signals demonstrate this farther.展开更多
In this paper, a frequency domain decision feedback equalizer is proposed for single carrier transmission with time-reversal space-time block coding （TR-STBC）. It is shown that the diagonal decision feedback equaliz...In this paper, a frequency domain decision feedback equalizer is proposed for single carrier transmission with time-reversal space-time block coding （TR-STBC）. It is shown that the diagonal decision feedback equalizer matrix can be calculated from the frequency domain channel response. Under the perfect feedback assumption, the proposed equalizer can approach matched filter bound （MFB）. Compared with the existing time domain decision feedback equalizer, the proposed equalizer exhibits better performance with the same equalization complexity.展开更多
逆向思维是决策中常用的一种思维方法,但目前的反馈外延决策方法(Decision-making of Feedback Extension,DFE)均未考虑这一点。为此,在因素空间理论基础上,从对立概念角度出发构造了一种概念的外延逼近即反馈外延外包络,在此基础上提...逆向思维是决策中常用的一种思维方法,但目前的反馈外延决策方法(Decision-making of Feedback Extension,DFE)均未考虑这一点。为此,在因素空间理论基础上,从对立概念角度出发构造了一种概念的外延逼近即反馈外延外包络,在此基础上提出了基于反馈外延外包络的DFE决策方法。通过土壤肥力评级的实例验证了该方法的有效性和可行性。展开更多
提出了一种适用于超短距离(Very Short Reach,VSR)信道、面向112 Gb/s PAM4(Pulse Amplitude Modulation 4)接收机的自适应均衡设计方案。在该方案中,接收机前端利用3个连续时间线性均衡器(Continuous Time Linear Equalizer,CTLE)对信...提出了一种适用于超短距离(Very Short Reach,VSR)信道、面向112 Gb/s PAM4(Pulse Amplitude Modulation 4)接收机的自适应均衡设计方案。在该方案中,接收机前端利用3个连续时间线性均衡器(Continuous Time Linear Equalizer,CTLE)对信号分别在高频、中频和低频进行补偿,可变增益放大器(Variable Gain Amplifier,VGA)和饱和放大器(Saturation Amplifier,SatAmp)则用于对信号幅值的缩放。除了3个数据采样器外,引入4个辅助采样器用于进一步改善阈值自适应算法性能。同时,采用符号最小均方算法,利用接收端数据采样器和辅助采样器之间的偏移推动辅助参考电压收敛到信号星座电平,从而确保PAM4接收信号的眼图在垂直方向上3个眼睛具有相等的间隔和恒定的信噪比(Signal-to-Noise Ratio,SNR)。仿真结果表明,所提出的112 Gb/s PAM4接收机能够在损耗为15 dB的信道上实现小于10~(-12)的误码率,并且具有良好的眼图性能,其最差眼高为75 mV,眼宽为0.34 UI(Unit Interval),与传统方案相比具有显著的性能提升。展开更多
基金Supported by the National Natural Science Foundation of China
文摘A Simple and useful decision feedback equalizer used for non-linear channels with severe linear distortion and mild non-linear distortion is proposed. It is a combination of a nonlinear channel equalizer based on connectionist model and a common decision feedback equalizer for linear channels. For a typical non-linear channel model it is shown that the equalization performances of the proposed equalizer are improved significantly.
文摘An adaptive support vector machine decision feedback equalizer（ASVM-DFE） based on the least square support vector machine（LS-SVM） is proposed,it solves linear system iteratively with less computational intensity.An adaptive non-singleton fuzzy support vector machine decision feedback equalizer（ANSFSVMDFE） is also presented,it adopts the non-singleton fuzzy Gaussian kernel function with similar characteristic of pre-filter and is modified with a space transformation based approach.Simulations under nonlinear time variant channels show that ASVM-DFE and ANSFSVM-DFE perform very well on nonlinear equalization and ANSFSVM-DFE acts especially well in resisting abrupt interference.
文摘A new equalization method is proposed in this paper for severely nonlinear distorted channels. The structure of decision feedback is adopted for the non-singleton fuzzy regular neural network that is trained by gradient-descent algorithm. The model shows a much better performance on anti-jamming and nonlinear classification, and simulation is carried out to compare this method with other nonlinear channel equalization methods. The results show the method has the least bit error rate （BER）.
基金The National Natural Science Foundation of China (No. 603320307)
文摘Least mean square (LMS) decision feedback equalizer (DFE) is preferred as an effective solution to coping with inter-symbol interference (ISI) for ATSC digital television (DTV) receivers. In DTV transmission environment, echo delay often covers several hundreds symbols, which leads to very large-scale equalizer. One consequence of the large-scale equalizer is the very slow convergence, which combined with error propagation, inherent drawback of DFE, seriously deteriorates the performance of the receivers, especially in severe channels More working modes and corresponding robust control mechanism were given to help the equalizer converge to the stable state smoothly. Simulation results show that the improved equalizer can perform better, especially in the severe channels.
基金Supported by the High Technology Research and Development Programme of China (No. 2003AA31g030).
文摘A 6.25 Gbps SerDes core used in the high speed backplane communication receiver has been designedbased on the OIF-CEI-02.0 standard. To counteract the serious Inter-Symbol-Interference (ISI),the core employed a half-rate four-tap decision feedback equalizer (DFE). The equalizer used the Sign-signleast mean-squared (SS-LMS) algorithm to realize the coefficient adaptation. An automatic gain control(AGC) amplifier with the sign least mean-squared (S-LMS) algorithm has been used to compensatethe transmission media loss. To recover the clock signal from the input data serial and provide for theDFE and AGC, a bang-bang clock recovery (BB-CR) is adopted. A third order phase loop lock (PLL)model was proposed to predict characteristics of the BB-CR. The core has been verified by behavioralmodeling in MATLAB. The results indicate that the core can meet the specifications of the backplane receiver.The DFE recovered data over a 34' FR-4 backplane has a peak-to-peak jitter of 17 ps, a horizontaleye opening of 0.87 UI, and a vertical eye opening of 500 mVpp.
基金This work was supported by the National Natural Science Foundation of China(NSFC)(Nos.62301128,61871082,and 62111530150)the Open Fund of IPOC(BUPT)(No.IPOC2020A011)+1 种基金the STCSM(No.SKLSFO2021-01)the Fundamental Research Funds for the Central Universities(Nos.ZYGX2020ZB043 and ZYGX2019J008).
文摘We propose a trellis-compressed maximum likelihood sequence estimation(TC-MLSE)-assisted sliding-block decision feedback equalizer(DFE)to suppress the error propagation resulting from the DFE in high-speed systems.We use an out-ofrange detector to detect the end of burst errors from the DFE and activate the optional TC-MLSE to correct burst errors.We conduct experiments to transmit a 201-Gbit/s PAM-8 signal.The results show that the proposed method achieves a bit error rate of 3.65×10^(-3),which is close to that of MLSE.The optional MLSE is only activated when needed and processes 11.4%of the total symbols.Moreover,the proposed method compresses the maximum length of burst errors from 19 to 5.
文摘In this paper,an efficient Cyclic Prefix (CP) reconstruction scheme is proposed for Sin-gle-Carrier systems with Frequency-Domain Equalization (SC-FDE) that employ insufficient length of CP at the transmitter. By utilizing a decision feedback filter to cancel the residual InterSymbol In-terference (ISI) in the equalized signal,the proposed scheme can effectively lower the low bound of performance for the CP reconstruction schemes and can greatly improve the Bit Error Rate (BER) performance of SC-FDE systems. In addition,the existing methods and the proposed scheme are also optimized. It is shown in the simulation results that,when the Signal-to-Noise Ratio (SNR) exceeds a certain threshold,the proposed scheme can achieve the low bound of performance for the existing methods. Moreover,by increasing the number of iteration or through optimization,the low bound can be outperformed.
基金Supported by the National High Technology Research and Development Programme of China(No.2011AA10305)
文摘This paper presents a 10Gb/s high-speed equalizer as the front-end of a receiver for backplane communication.The equalizer combines an analog equalizer and a two-tap decision-feedback equalizer in a half-rate structure to reduce the inter-symbol-interference(ISI) of the communication channel.By employing inductive peaking technique for the high-frequency boost circuit,the bandwidth and the boost of the analog equalizer are improved.The decision-feedback equalizer optimizes the size of the CML-based circuit such as D flip-flops(DFF) and multiplex(MUX),shortening the feedback path delay and speeding up the operation considerably.Designed in the 0.18μm CMOS technology,the equalizer delivers 10Gb/s data over 18-in FR4 trace with 28-dB loss while drawing27-mW from a 1.8-V supply.The overall chip area including pads is 0.6×0.7mm^2.
文摘In digital radio communication, diversity reception can combat flat fadingand adaptive equalization can combat Inter-Symbol Interference (ISI). In this paper, the structureand algorithm of a multi-channel equalizer with combined diversity reception and adaptiveequalization techniques are studied. Because Phase-Looked-Loops (PLL) are embedded in the equalizer,this equalizer is suitable for coherent communication in channels with high phase fluctuation.Monte Carlo simulation is used to test its performance and the results show that a multi-channeldecision-feedback-equalizer has better performance than a single-channeldecision-feedback-equalizer, and the results of processing high-speed digital underwatercommunication signals demonstrate this farther.
基金supported by the National Basic Research Program of China (2009CB320401)the National Key Scientific and Technological Project of China (2010ZX03003-001,2010ZX03003-003-01)+2 种基金the Research Funds for Doctoral Program of Higher Education of China (20090005110003)the National Natural Science Foundation of China (60902048)the Fundamental Research Funds for the Central Universities (2010PTB-03-04 G470220)
文摘In this paper, a frequency domain decision feedback equalizer is proposed for single carrier transmission with time-reversal space-time block coding （TR-STBC）. It is shown that the diagonal decision feedback equalizer matrix can be calculated from the frequency domain channel response. Under the perfect feedback assumption, the proposed equalizer can approach matched filter bound （MFB）. Compared with the existing time domain decision feedback equalizer, the proposed equalizer exhibits better performance with the same equalization complexity.
文摘逆向思维是决策中常用的一种思维方法,但目前的反馈外延决策方法(Decision-making of Feedback Extension,DFE)均未考虑这一点。为此,在因素空间理论基础上,从对立概念角度出发构造了一种概念的外延逼近即反馈外延外包络,在此基础上提出了基于反馈外延外包络的DFE决策方法。通过土壤肥力评级的实例验证了该方法的有效性和可行性。
