481 research outputs found
Performance of DPSK Signals with Quadratic Phase Noise
Nonlinear phase noise induced by the interaction of fiber Kerr effect and
amplifier noises is a quadratic function of the electric field. When the
dependence between the additive Gaussian noise and the quadratic phase noise is
taking into account, the joint statistics of quadratic phase noise and additive
Gaussian noise is derived analytically. When the error probability for
differential phase-shift keying (DPSK) signals is evaluated, depending on the
number of fiber spans, the signal-to-noise ratio (SNR) penalty is increased by
up to 0.23 dB due to the dependence between the Gaussian noise and the
quadratic phase noise.Comment: 15 pages, 2 figure
Interleaver design for trellis-coded differential 8-PSK modulation with non-coherent detection
The effect of finite interleaver size on bit error rate (BER) performance of coded 8-DPSK is determined by means of computer simulations. The losses evaluated in this way include the SNR degradation due to the timing and frequency errors of the symbol synchronizer and the automatic frequency control (AFC) of the receiver. BER measurements are presented using a conventional 2/3 rate convolutional 8-state trellis-code for typical Rayleigh and Rician fading channels. It is shown that for a Rician channel with a Rician parameter of 7 dB, a Doppler spread of 100 Hz and a data rate of 2400 bps, an interleaver with size 16 x 16 symbols performs nearly as well as a very large interleaver. It is also shown that for very fast Rayleigh channels, the BER-curves flatten out at large SNR
Differential Diversity Reception of MDPSK over Independent Rayleigh Channels with Nonidentical Branch Statistics and Asymmetric Fading Spectrum
This paper is concerned with optimum diversity receiver structure and its
performance analysis of differential phase shift keying (DPSK) with
differential detection over nonselective, independent, nonidentically
distributed, Rayleigh fading channels. The fading process in each branch is
assumed to have an arbitrary Doppler spectrum with arbitrary Doppler bandwidth,
but to have distinct, asymmetric fading power spectral density characteristic.
Using 8-DPSK as an example, the average bit error probability (BEP) of the
optimum diversity receiver is obtained by calculating the BEP for each of the
three individual bits. The BEP results derived are given in exact, explicit,
closed-form expressions which show clearly the behavior of the performance as a
function of various system parameters.Comment: 5 pages, 3 figures, to present at ISIT200
Scalable WDM phase regeneration in a single phase-sensitive amplifier through optical time lenses
Scalable solutions for data regeneration of multiple parallel channels are elusive. Here the authors report a scalable wavelength-division multiplexing technique for phase regeneration and demonstrate the highest reported number of regenerated wavelength-division multiplexed channels in a single phase regenerator
Adaptive Importance Sampling for Performance Evaluation and Parameter Optimization of Communication Systems
We present new adaptive importance sampling techniques based on stochastic Newton recursions. Their applicability to the performance evaluation of communication systems is studied. Besides bit-error rate (BER) estimation, the techniques are used for system parameter optimization. Two system models that are analytically tractable are employed to demonstrate the validity of the techniques. As an application to situations that are analytically intractable and numerically intensive, the influence of crosstalk in a wavelength-division multiplexing (WDM) crossconnect is assessed. In order to consider a realistic system model, optimal setting of thresholds in the detector is carried out while estimating error rate performances. Resulting BER estimates indicate that the tolerable crosstalk levels are significantly higher than predicted in the literature. This finding has a strong impact on the design of WDM networks. Power penalties induced by the addition of channels can also be accurately predicted in short run-time
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