The most complete instrument on the market now incorporates a new function: the impulse response

July 1, 2005.

PROLINK-4 PremiumWe introduce the new channel impulse response function for field strength meters models PROLINK-4C Premium and PROLINK-4 Premium. This feature allows the detection of "echoes" in reception. This function will be included as standard in the instruments of new delivery. If required, it is also possible to upgrade the firmware of the instruments in the field.

DVB-T digital terrestrial television has begun to be implemented in a few countries whilst in many other countries the introduction is planned.

Working in Single Frequency Networks, all the transmitters in the covered area transmit the same programme in the same channel. It is necessary that all the transmitters are very well synchronised both in time and in frequency. Usually, GPS based systems are used for this purpose.

In the area where the coverage maps from different transmitters overlap, the signals from different transmitters reach the same receiver at different instants of time.

The guard interval is the period of time that the signal incorporates to absorb these differences in the arrival time to the receiver, so that only one of the signals is going to be considered as a reference and the rest will be echoes.

Impulse response

The new impulse response function built in the field strength meters models PROLINK-4C Premium and PROLINK-4 Premium allows the graphic analysis of this guard interval and the different events.

Field strenght meter with impulse response

The horizontal axis shows the different arrival times of the signals from the different transmitters and the vertical axis shows the level.

The distance in kilometres for the different arrival paths is also indicated on the screen. The further the distance to the transmitter, the longer the time required for the signal to reach the receiver.