Attachment b. Methodical manual for the course work
Topic of the course work «Optimisation methods of error-control coding for transmission system»
Introduction. In Chapter 12 it is shown, that error-control coding is effective means for the optimisation of transmission systems. In practice engineer-designer should solve optimisation problems on the basis of numerical calculations and corresponding comparison of a coding methods and a choice of concrete coding methods and corresponding to them the codes. The solution of such problem was underlay in basis of the course work.
Input data are set in the table of variants (table B.2):
1. The digital binary signal with rate R is subject to transfer.
2. The transmission channel is the channel with constant parameters and additive white noise.
3.
Signal to noise ratio on a demodulator
input is
.
4. Methods of modulation are BPSK or QPSK.
5. Mode of reception is coherent.
6. Pass band of transmission channel is Fch.
7. Probability of an error on an output of transmission system no more pacc.
8. Permissible complexity of a code trellis – no more Cperm.
It is necessary:
1. To choose and justify a choice of a error-control code for projected system, ensuring demanded bit error probability level pacc under condition of a following restrictions:
1.1. The bandwidth of the modulated signal Fs should not exceeds of a Pass band of transmission channel Fch (Fs < Fch).
1.2. By using of convolution codes the code trellis complexity should be no more magnitude Cperm.
2. To develop and give detailed exposition structural and function schemes of the encoder and the decoder for the chosen code and to justify their parameters.
3. To analyze of energy and frequency efficiency of a projected transmission system and to compare them to limiting values of efficiency.
4. To make a conclusion on the done work.
The content of the executed work
1. The introduction and input data.
2. Exposition of the block diagram of designed transmission system with indication of inclusion places of the error-control encoder, modulator, demodulator and the decoder with detailed explanations of functions fulfilled by them.
3. An application substantiation in the work of convolution codes.
4. A substantiation of a Viterbi algorithm choice for decoding of a convolutional code.
5. Calculation of a bandwidth occupied with a modulated signal Fs at code rates 1/8, 1/4, 1/3, 1/2, 1.
6.
Definition of an admissible code rate
by a condition 1.1 (Fs
< Fch).
7. Definition of the enumeration of codes with the rates which are not exceeding admissible rate which can be used for a task in view solution.
8. Choice codes from this enumeration ensuring given bit error probability level by the condition 1.1 and restriction satisfying to the requirement on decoder complexity (by condition 1.2).
9. Checking calculation of a bit error probability for the decoding of the chosen code.
10. Elaborating and exposition of a structural and function schemes of the encoder and the decoder chosen code.
11. A conclusion with summarising of the performed work.
12. The list of the used literature.