hannel and output power. The power meter is used to sample the transmitted power and could be a spectrum analyzer, base station simulator with integrated power meter, or a regular power meter-whichever is most suitable in the specific measurement case. Figure 12.7 shows the schematic setup for TRP measurements. Handheld units are often tested in simulated-use position (e.g., with a head or hand phantom in the close vicinity of the test unit). The reverberation © 2009 by Taylor & Francis Group, LLC Long Term Evolution: 3GPP LTE Radio and Cellular Technology Reverberation Chamber Fixed-measurement antenna Power meter stirrer/tuner Base station simulator Test unit Separated up- and downlink paths Reverberation Chamber Fixed-measurement antenna Same path for up- and downlink Mode stirrer/tuner Base station simulator Test unit Figure 12.7 Schematic setups for TRP measurements. Alternative b, with the same up- and downlink paths, can also be used for sensitivity measurements. chamber is very suitable for simulated-use testing due to the simple positioning of test units. In a reverberation chamber, the statistical field uniformity makes it possible to place the test object/antenna in any position and orientation in the chamber, as long as it is far enough from any other object not to give a reduction of the antenna's radiation efficiency. As described in the calibration procedure earlier, a distance of half of a wavelength from walls and other reflecting objects and 70% of a wavelength from power-absorbing objects is enough for low-gain antennas. This is also true for the combination of a test unit and a head phan- tom, for example; this means that as long as the combination of the two is placed far enough from other objects in the chamber, the effective radiation efficiency that will determine the TRP value is the efficiency of the test unit and the head phantom combined, in the specific relative position they are placed. Note that when head or hand phantoms are used, these objects must also be present in the © 2009 by