Mobile communication -- simulation model of error control system based on convolutional code

Abstract

Channel coding is an important part of digital communication system , It is an important way to ensure reliable signal transmission . Convolutional codes are widely used in digital communication systems because of their superior performance . This modern wireless communication operation is mainly used SIMULINK A simulation model of error control system based on convolutional code is designed ,
And pass MATLAB Conduct performance simulation analysis of the system . Solve the Viterbi of a convolutional code sequence (Viterbi) Decoding output , The bit error rate of the control system is simulated from three cases of convolutional coding soft decision, convolutional coding hard decision and no coding , With BPSK Take the modulation method as an example , And by building simulink Module collaboration Matlab Script writing for design and simulation , And analyze the bit error rate . Adopt additive Gaussian white noise channel , use BPSK Demodulate and use Viterbi decoding under soft decision and hard decision respectively , utilize MATLAB synergy simulink On the way of decision 、 Convolutional coding efficiency 、 Viterbi decoding backtracking depth auto tuning , The bit error rate relationship of Viterbi decoding under different signal-to-noise ratios is studied , Through the curve, the simulation is consistent with the theoretical analysis .

Convolutional code （convolutional code） By Elia
Si (P.Elias) On 1954 A non block code first proposed in . through
Often it is more suitable for forward error correction , Because for many practical situations it
Its performance is better than block code , And the operation is relatively simple . In theory
Its performance has been proved to be better than that of linear block codes . volume
The wide application of product code in communication system convolutional code is a kind of performance
Superior channel coding , Its encoder and decoder are relatively easy
Realization , At the same time, it also has strong error correction ability , With error correction coding
The continuous deepening of theoretical research , Convolutional codes are more and more widely used in practice
extensive . This modern wireless communication operation selects applications SIMULINK
A simulation model of error control system based on convolutional code is designed , And connect
too MATLAB Conduct performance simulation analysis of the system . The model includes
Source part 、 Channel part and sink part , Data of the source part
The source is a random binary sequence , Random binary sequences go through
Convolutional coding , The encoded data should be modulated . Channel part
Add noise to the modulated signal , Adopt additive Gaussian white noise .
The sink part completes the demodulation and decoding of the signal （ Viterbi decoding ）.
Through this design, it is easy to understand the functions of each module , The meaning of each parameter
The righteous ; And analyze the bit error rate of Viterbi decoding under different signal-to-noise ratio
System curve , Deepen the theory of Toby decoding principle and convolutional code decoding
Explain .