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1.
A multisensor decision feedback equaliser based on the minimum mean squared error (MMSE) criterion is studied. The superiority of the performance of the multisensor equaliser is shown by simulation of a whole communication system in which the adaptive equaliser is incorporated. The recursive least squares (RLS) algorithm is used to update the coefficients. From the results obtained for a time-varying urban terrain channel model, the extremely interesting tracking capability of the multisensor equaliser is shown  相似文献   

2.
A 2-D adaptive piecewise-linear equaliser is proposed. As an alternative of the 2-D adaptive Volterra equaliser, the proposed equaliser has advantages in its suitability for cases of strong nonlinearity and saving implementation and computation cost. An experiment examples is presented which demonstrates the superior behaviour of this method over either a linear method or the Volterra method in inverse modelling an unknown 2-D channel with blurring and a common point-wise nonlinearity and restoring images degraded by this channel.<>  相似文献   

3.
A novel adaptive noncoherent linear minimum mean squared error equaliser for 16-level differential amplitude/phase shift keying signals is proposed. A novel modified least mean square algorithm is derived which allows an efficient equaliser adaptation. Simulations confirm the high performance of the proposed noncoherent equaliser and its robustness against carrier phase variations  相似文献   

4.
The authors propose a technique to counteract the ill-conditioning of the blind fractionally spaced equaliser. The technique involves whitening the signal at the equaliser input and introducing a leakage term in the cost function minimised by the equaliser. The result is that, when applied to the Godard quartic cost function and to the infinitely long equaliser, such a technique yields optimal equalisation and actually counteracts the ill-conditioning  相似文献   

5.
Taylor  D.P. 《Electronics letters》1971,7(10):265-267
An adaptive feedback equaliser using a soft limiter in the feedback path is briefly described. Curves and figures describing its adaptive behaviour are presented, and a brief comparison with the decision-feedback equaliser, which uses a hard limiter in the feedback path, is made.  相似文献   

6.
A multisensor equaliser based on the Viterbi algorithm is presented. The equaliser consists of a multisensor Viterbi estimator and adaptive channel estimators. Its complexity is described and its performance over mobile channels is analysed. It is concluded that the multisensor Viterbi equaliser is capable of considering truncated channels, thereby allowing a considerable reduction in complexity  相似文献   

7.
A new equaliser for digital communication channels, which carries out a discrete-time fixed-lag smoothing of the state vector of the channel, modelled as a tapped delay line of finite length, is proposed. The smoothed estimate uses and improves the filtered estimate of the conventional Kalman-filter equaliser.  相似文献   

8.
Blind equalisation of a fractionally spaced channel (FSC) is generally difficult if all subchannels have common zeros. A new blind equalisation structure is proposed so that the uncommon part of the FSC is equalised with a fractionally spaced equaliser and the common part of the FSC is equalised with a decision feedback equaliser which operates at the baud rate  相似文献   

9.
The fabrication of a polarisation-dependent loss (PDL) equaliser using tilted fibre Bragg grating in standard telecommunication fibre is demonstrated. The equaliser has a predetermined level of PDL in a specific wavelength range, which is studied to compensate for the PDL of a component or system  相似文献   

10.
Chuah  T.C. 《Electronics letters》2004,40(6):369-371
A new Viterbi equaliser is proposed for joint mitigation of intersymbol interference and impulsive noise. The new equaliser uses a robust branch metric incorporating the Talwar penalty function. It is shown that the proposed equaliser facilitates considerable performance improvements.  相似文献   

11.
The authors propose to combine linear feedback equalisation and decision feedback demodulation for the equalisation of differentially coherent PSK signalling. By modifying the equaliser output based on the decision feedback demodulation before feeding back, the proposed equaliser can be made to behave like one with a decision feedback structure. Indeed, computer simulation results demonstrate that this equaliser performs much better than existing equalisers, such as linear equalisers for differentially coherent detection. Furthermore its performance is even comparable to that of a decision feedback equaliser with coherent detection  相似文献   

12.
The authors report the fabrication of an integrated-optic dispersion equaliser module based on a planar lightwave circuit (PLC). The equaliser consists of five asymmetrical Mach-Zehnder interferometers cascaded in series. Polyimide half waveplates inserted in the interferometers eliminate the polarisation dependent path length differences of the equaliser  相似文献   

13.
By adaptively detecting abrupt changes in the channel tap coefficients and requesting the training sequence to be transmitted whenever changes are detected, an adaptive retraining equaliser has been designed. The performance of the equaliser is evaluated by numerical simulations, and the results show that the equaliser outperforms the traditional periodical retraining equaliser and requires fewer training sequences.  相似文献   

14.
In this article, a voltage equaliser is proposed for a battery string with four Li–Fe batteries. The proposed voltage equaliser is developed from a flyback converter, which comprises a transformer, a power electronic switch and a resonant clamped circuit. The transformer contains a primary winding and four secondary windings with the same number of turns connected to each battery. The resonant clamped circuit is for recycling the energy of leakage inductance of the transformer and for performing zero-voltage switching (ZVS) of the power electronic switch. When the power electronic switch is switched on, the energy is stored in the transformer; and when the power electronic switch is switched off, the energy stored in the transformer will automatically charge the battery whose voltage is the lowest. In this way, the voltage of individual batteries in the battery string is balanced. The salient features of the proposed voltage equaliser are that only one switch is used, the energy stored in the leakage inductance of the transformer can be recycled and ZVS is obtained. A prototype is developed and tested to verify the performance of the proposed voltage equaliser. The experimental results show that the proposed voltage equaliser achieves the expected performance.  相似文献   

15.
Takiguchi  K. Okamoto  K. 《Electronics letters》1994,30(17):1404-1406
The authors report an integrated-optic dispersion equaliser with an amplitude flattening circuit on a planar lightwave circuit. The equaliser consists of six asymmetrical Mach-Zehnder interferometers cascaded in series. The operational frequency range of the equaliser is successfully extended from 12.6 to 21.2 GHz by amplitude flattening without deteriorating the delay characteristics  相似文献   

16.
The paper proposes a recursive single-most-likely-replacement (SMLR) equaliser, that is a fixed-lag block signal processing algorithm indexed by the block size L and the number of decisions N⩽L at each recursion, for channels in the presence of intersymbol interference of finite or infinite length and additive white Gaussian noise. Both computational load and storage required by the proposed recursive SMLR equaliser are linearly proportional to the block size. Two simulation examples illustrate the performance of the proposed recursive SMLR equaliser  相似文献   

17.
The authors present a performance-robustness evaluation of the recently developed minimal resource allocation network (MRAN) for equalisation in highly nonlinear magnetic recording channels in disc storage systems. Unlike communication systems, equalisation of signals in these channels is a difficult problem, as they are corrupted by data-dependent noise and highly nonlinear distortions. Nair and Moon (1997) have proposed a maximum signal to distortion ratio (MSDR) equaliser for data storage channels, which uses a specially designed neural network, where all the parameters of the neural network are determined theoretically, based on the exact knowledge of the channel model parameters. In the present paper, the performance of the MSDR equaliser is compared with that of the MRAN equaliser using a magnetic recording channel model, under Conditions that include variations in partial erasure, jitter, width and noise power, as well as model mismatch. Results from the study indicate that the less complex MRAN equaliser gives consistently better performance robustness than the MSDR equaliser in terms of signal to distortion ratios (SDRs)  相似文献   

18.
A new structure for a code-aided adaptive equaliser is proposed for mobile communication systems. The structure aims to improve the tracking capability of a receiver that combines equalisation and coding. Simulation results show that the code-aided adaptive equaliser performs particularly well over mobile channels that fade at a moderate rate. Compared to a conventional equaliser, an order of magnitude reduction in bit error rate is achieved  相似文献   

19.
The authors describe the design and CMOS realisation of a new g m-C amplitude equaliser for correcting sinc(x) distortion in video D/A converters. Simulated and measured results demonstrate how the equaliser is used to correct distortion in D/A converters with Fs =13.5 MHz to ⩽0.08 dB ripple over 5 MHz bandwidth. Fabricated using a 0.8 μm CMOS process, the equaliser occupies 0.7 mm2 and dissipates 20 mW from a 5 V supply  相似文献   

20.
Chromatic dispersion compensation of non-return-to-zero on?off keying (NRZ-OOK) signals with a diverse-vestigial-sideband-filtering feed forward equaliser and a decision feedback equaliser (DVSB-FFEDFE) is presented, in which diverse vestigial sideband (VSB) filtering is realised with a Mach-Zehnder (MZ) filter. In a 10.709 Gbit/s NRZOOK system, experiment results show that the standard singlemode fibre transmission distance at 3 dB optical signal-to-noise ratio penalty with DVSB-FFE-DFE is doubled, compared to that with conventional FFE-DFE.  相似文献   

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