Future telecommunication systems require good performances at the receivers, such as a high data rate, low bit error rate (BER), etc. However, the transmitted signal changes when it travels from the transmitter to the receiver. It may be affected by the distance between the transmitter and the receiver, the environment, and the speed of the mobile. Hence, synchronization and equalization play an important role to demodulate received data correctly in a mobile system.
On one hand, intersymbol interference (ISI) is an unwanted phenomenon caused by multipath fading. As a result, the receiver receives different versions of the same signal. On the other hand, the channel characteristics are often unknown and time variant. The equalizer is required to remove the ISI and compensate the negative effect of the channel. In addition, it must adapt to the channel variations which are undesirable. Normally, a training sequence is used to obtain convergence of the equalizer coefficients. Then, the decision directed mode benefits the entire transmission band to transmit information.
Another important component is the frame synchronization, which helps to demodulate correctly the symbols and the frame of the symbol. As part of our research, the rapidly time variant channel is built. Then, by observing the variations of the coefficients of the equalizer, the change of the most important coefficient of the equalizer is found. Finally, if the equalizer can’t compensate the negative effect of the channel, a method which is based on the variation of the most important coefficient of the equalizer is proposed.
| Date | 21 Mar 2013 |
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| Original language | French |
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| Awarding Institution | - École de technologie supérieure
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| Supervisor | François Gagnon (Supervisor) & Ghyslain Gagnon (Co-supervisor) |
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Le, D. B. (Author),
Gagnon (Supervisor) &
Gagnon (Co-supervisor),
21 Mar 2013Student thesis: Master's thesis › Master in Engineering: Engineering