Testing of the Carrier Aggregation Mode for a Live LTE Base Station in Reverberation Chamber

For the first time, the carrier aggregation feature of a live 4G-LTE base station (BS) is checked adopting a reverberation chamber as a propagating environment. To that purpose, two non adjacent bands were chosen: 800 and 1800 MHz and alternatively set as primary and secondary cells. The multipath conditions were tuned by adding the absorbing material inside the chamber and ranging from an empty condition with a rich multipath to a real environment like an indoor scenario. The latter is a very interesting and popular situation as it represents one in which people use mobile phones. The multipath variation effect on the BS performance was accurately verified by introducing power compensation in order to account for the variation of the chamber quality factor Q due to the insertion of absorbers. A complete over-the-air test was carried out by checking typical transmission quality parameters, that are of interest to manufacturers and mobile network operators. Results highlight differences between the performance of the two bands as a function of multipath degree and signal strength.