The aim of this project was to redesign an existing wireless transmission system for video signals. This wireless video link is part of the LokSim project which is described at the beginning of this thesis.

In previous projects, a video link based on a satellite television chip has already been realised. This transmission system was very error-prone because of multi-path fading. The reason for its sensitivity was a missing limiter at the discriminator input.

In this project, the video link was to be designed on the basis of a WLAN chip (Wireless Local Area Network). This chip, LMX3162, designed for the use in the ISM-band (2.4 - 2.495GHz), was chosen as the main part of the transmitter as well as the receiver. The errors caused by multi-path fading should be greatly reduced because of the internal limiter of the LMX3162

In two previous projects the frequency synthesiser was designed and the chip was tested with the required bandwidth of 30 MHz. In this project we realised the whole transmission system from transmitter input to receiver output. Some of the most important obstacles to overcome were the design of the HF-parts, the IF-filter, the frequency-synthesiser and the coupling of the modulation signal into the PLL frequency synthesiser.

The result of this project is a wireless transmission system which transmits the video signal with little degradation due to multi-path fading. This is very important, especially for the use in the Lok-Sim project. For a medium input level the S/N-ratio reached the requirements of 35dB. At the minimum input level the required S/N-ratio cannot be guaranteed. If the input level drops below the minimum level of -80dBm the transmission breaks down.

Through the combination of two spacially separated receivers, and the selection of the better of the two receiver signals, these breakdowns could eventually be eliminated.