ECO CANCELATION COVERAGE ENHANCER TETRA REPEATER
The coverage enhancer RIT380 developed by AD Telecom is especially designed for the enhancement of TETRA network's coverage. This devices are designed to operate without human intervention, under stringent environmental requirements, with a high degree of reliability. The equipment has also the capability of being completely controlled and monitored remotely.
It is based on an isofrequency processor that services up to 8 physical TETRA channels. The internal architecture of the digital processor is split into 16 monochannel processing units, from which 8 units are for uplink and the remaining 8 units are for downlink. Each monochannel subsystem basically performs channel filtering and cancellation of coupling.
The advantages of RIT380 compared to competitor's TETRA repeaters, lies in coupling cancellation: in current systems, the signal transmitted is partially coupled to the signal received due to the coupling between transmitting and receiving antennas, which leads to working with gain levels below that coupling. If the gain was increased, the system would become unstable and stop being operative.
The RIT380 coverage enhancer uses signal processing techniques for cancelling the coupling between antennas. The use of those algorithms allow to cancell coupling and work stably with gains 20dB over antenna coupling. This implies a substantial improvement over current repeaters, that usually work with gains of 10dB below antennas coupling in order to avoid oscillation problems, and allows it to work under conditions in which achieving a big antenna isolation is difficult
