ctly connecting attenuators at the base station and terminal antenna ports or, alternatively, by a setup using two connected © 2009 by Taylor & Francis Group, LLC Measuring Performance of 3GPP LTE Terminals Delay Delay Delay Delay Delay Delay Absorbers Figure 12.15 Two-chamber setup, where a mobile station (MS) is placed in the left chamber and the base station (BS) is placed in the right chamber. Both cham- bers are connected via transmission lines with different delays and attenuators to manipulate the frequency-selective behavior of the channel. The right cham- ber additionally uses absorbers to manipulate the angular spread of the channel. Note that the number of pickup antennas connecting the two chambers needs to be sufficiently high in order not to limit the rank of the MIMO channel. reverberation chambers, as illustrated in Figure 12.15. In this setup, the mobile ter- minal is placed in the left chamber, which is equipped with a turntable and stirrers on the wall as described previously. The chamber on the right-hand side hosts the base station (antennas). Both chambers are connected to each other via pickup antennas in each cham- ber, which are connected through a transmission line [5]. Rather than using only Figure 12.16 Two base station setups with handover region. Note that cells are based on receiver power rather than on geometry. In the handover area, the aver- age power received by a mobile from two different base stations is approximately the same. This corresponds to the uniform average power distribution over the area in the reverberation chamber. Note that the handover area or cell edge in a communication system is not defined by geometry but rather by signal power levels. © 2009 by Taylor & Francis Group, LLC Long Term Evolution: 3GPP LTE Radio and Cellular Technology transmission lines, one might in addition use attenuators and, potentially, elements introducing a propagation delay. If the delay elements impose a different propaga- tion delay in different transmission lines, the channel becom