Summary
Channel coding is an important part of digital communication systems. It is an important way to ensure reliable signal transmission. Convolutional codes are widely used in digital communication systems due to their superior performance. This modern wireless communication project mainly uses SIMULINK to design an error control system simulation model based on convolutional codes,
and conducts performance simulation analysis of the system through MATLAB. To solve the problem of Viterbi decoding output of a convolutional code sequence, simulate the bit error rate of the control system in three cases: convolutional coding soft decision, convolutional coding hard decision and no coding, using BPSK modulation method As an example, we designed and simulated by building a simulink module and writing Matlab scripts, and conducted bit error rate analysis. Additive Gaussian white noise channel is used, BPSK demodulation is used, and Viterbi decoding under soft decision and hard decision is used respectively. MATLAB is used in conjunction with simulink to automatically adjust parameters for the decision-making method, convolutional coding efficiency, and Viterbi decoding backtracking depth. Study the relationship between the bit error rates of Viterbi decoding under different signal-to-noise ratios, and draw a conclusion from the graph that the simulation is consistent with the theoretical analysis.
Convolutional code is
a non-blocking code first proposed by P. Elias in 1954. It is generally
more suitable for forward error correction because its
performance is better than block code for many practical situations and its operation is simpler. Both theoretically
and practically it has been proven that its performance is better than linear block codes. Convolutional
code is widely used in communication systems. Convolutional code is a
channel coding with superior performance. Its encoder and decoder are relatively easy
to implement. It also has strong error correction ability. With the error correction coding
With the continuous deepening of theoretical research, the practical applications of convolutional codes are becoming more and more extensive
. In this modern wireless communication project, SIMULINK was used to
design an error control system simulation model based on convolutional codes, and
MATLAB was used to conduct performance simulation analysis of the system. The model includes
a source part, a channel part and a sink part. The data source of the source part
is a random binary sequence. The random binary sequence needs to be
convolutionally encoded, and the encoded data needs to be modulated. The channel part
adds noise to the modulated signal, using additive Gaussian white noise.
The sink part completes signal demodulation and decoding (Viterbi decoding).
Through this design, it is easy to understand the functions of each module and the meaning of each parameter
; and analyze the bit error rate
relationship , and deepen the principle of Viterbi decoding and convolutional code decoding. understanding
.
