Master thesis The OCDM System Model is focused on problematics of multi carrier modulation techniques and in detail analyses the OCDM system. The first part of the work contains theoretical and mathematical description of digital communication system in general. The next part focuses on OCDM system and Fresnel transform, whose discrete form is kernel of the system. Digital model of the OCDM system is realized in programming language MATLAB. In the digital model is performed simulation of information from transmitter to receiver in AWGN and fading channel. The results are evaluated from the viewpoint of the system resilience against errors and achievable system throughput. The end of the master thesis is dedicated to mutual compatibility and comparison between OCDM and OFDM system.

One would like to evaluate and compare complex digital communication systems based upon their overall bit error rate. Unfortunately, analytical expressions for bit error rate for even simple communication systems are notoriously difficult to evaluate accurately. Therefore, communication engineers often resort to simulation techniques to evaluate these error probabilities. In this thesis importance sampling techniques (variations of standard Monte Carlo methods) are studied in relation to both linear and non-linear detectors. Quick simulation, an importance sampling method based upon the asymptotics of the error estimator, is studied in detail. The simulated error probabilities are compared to values obtained by numerically inverting Laplace Transform expressions for these quantities.