PROBABILITY OF BPSK SIGNAL RECEPTION ERROR IN PRESENCE OF SIMILAR HINDRANCE

2019 ◽  
pp. 55-59
Author(s):  
V. V. Zvonarev ◽  
I. A. Karabelnikov ◽  
A. S. Popov

The paper considers the problem of calculation of average probability of error of optimum symbol‑by‑symbol coherent reception of binary opposite phase‑shift keyed signals (BPSK) in the presence of similar synchronous noise. The noise similar to signal of PSK‑2 (BPSK), synchronous on clock periods, matching on frequency, differing in sequence of information characters and, perhaps, on initial phase of the bearing fluctuation is considered, up to mutual coherence of signal and noise. Formulas for calculation of probability of error are derived and results of partial computer type of diagrams of tension are given in some points of the correlation receiver. Optimum reception of discrete signals is carried out by means of the correlation receiver or the coordinated filter configured on signal in lack of noise in the presence of only receiver noises. It is shown that availability of synchronous similar or harmonious coherent noise, aim on structure, leads to decrease in noise stability of radio channel of information transfer. Than the level of noise is higher, that the probability of error is more.

Author(s):  
G. V. Kulikov ◽  
Trung Tien Do ◽  
E. V. Samokhina

Objectives. The widespread use of radio data transmission systems using signals with multiposition phase shift keying (MPSK) is due to their high noise immunity and the simplicity of constructing the transmitting and receiving parts of the equipment. The conducted studies have shown that the presence of non-fluctuation interference, in particular, harmonic interference, in the radio channel significantly reduces the noise immunity of receiving discrete information. The energy loss in this case, depending on the interference intensity, can range from fractions of dB to 10 db or more. Therefore, interference suppression is an important task for such radio systems. The aim of the work is to synthesize and analyze an algorithm for optimal nonlinear filtering of MPSK signals against a background of harmonic interference with a random initial phase.Methods. The provisions of the theory of optimal nonlinear signal filtering and methods of statistical radio engineering are used.Results. The synthesis and analysis of the algorithm of optimal nonlinear filtering of MPSK signals against the background of harmonic interference with a random initial phase are carried out. The synthesized receiver contains a discrete symbol evaluation unit, two phase-locked frequency circuits of reference generators that form evaluation copies of the signal and interference, and cross-links between them. Analytical expressions are obtained that allow calculating the dependences of the bit error probability on the signal-to-noise ratio and the interference intensity µ. It is established that uncompensated fluctuations of the initial phase of the useful signal have a greater effect on the receiver noise immunity than similar fluctuations of the phase of harmonic interference, especially with low positional signals.Conclusions. Comparison of the obtained results with the results obtained in the case when there are no harmonic interference compensation circuits shows that the use of the obtained phase filtering algorithms allows for almost complete suppression of harmonic interference. Thus, if µ = 0.5 and the probability of error is 10−2, the energy gain at M = 2 is about 2.5 dB, at M = 4 – about 6 dB, at M = 8 and M = 16 – at least 10 dB.


2012 ◽  
Vol 4 ◽  
pp. 43-50 ◽  
Author(s):  
Rao V. Srinivasa ◽  
Kumar P. Vinay ◽  
S. Balaji ◽  
Khan Habibulla ◽  
Kumar T. Anil

This paper presents the robust multiuser detection in synchronous direct sequence-code division multiple access (DS-CDMA) systems with Maximal Ratio Combiner (MRC) receive diversity over frequency-nonselective, slowly fading Nakagami-m channels in a non-Gaussian environment. Average probability of error is derived for decorrelating detector over single path Nakagami-m fading channel. A new M-estimator proposed to robustify the detector is studied and analyzed. Simulation results show that the new M-estimator outperforms linear decorrelating detector, the Huber, and the Hampel estimator based detectors.


The article discusses the issues of ensuring noise immunity in digital broadcasting systems, shows the importance of the transition to the optimal code and the need to use it in the field of noiseless coding in various areas of telecommunication transmission and reception of digital signals. The previous algorithms and error-correcting coding methods based on the Gray code, which are used in multi-level digital broadcast modulation schemes to minimize the intensity of bit errors, are highlighted. A model of error-correcting coding by the Gray method and methods for estimating the probability of error for the Gray code are presented. Based on computer modeling in the Matlab 7.0 Simulink environment, a model of a noise-resistant coding system was developed, which works on the basis of a parallel-cascade high-precision iterative coding and decoding algorithm, a method for determining and estimating the probability of error is given for the high-precision iterative coding and decoding algorithm, and the complexity of constructing a high-precision iterative code. The study obtained probabilistic-energy characteristics for the Gray code and for a high-precision iterative code in various positions of phase manipulation. A comparative analysis of the energy gain G (dB) of the high-precision iterative coding algorithm with the Gray coding algorithm is performed. The simulation results in a Simulink environment of an error-correcting Gray code and a high-precision iterative code in a digital information transfer system are presented


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