e (Chalmers Antenna Systems VINN Excellence Center) program [55]. A MIMO WLAN router and laptop were used to test throughput. WLAN devices were used because it was difficult to find prototype 3GPP LTE base stations and terminals in 2008. WLAN has some of the same properties (e.g., orthogonal frequency division mul- tiplexing [OFDM], 20-MHz bandwidth, and support for multiantenna solutions [802.11n]) as 3GPP LTE, and the results should therefore be relevant for designers of 3GPP LTE equipment. The setup for the throughput measurements is shown in Figure 12.12. The WLAN router under test was a D-Link RangeBooster N 650 wireless router (model DIR-635) with operation restricted to the 2.4-GHz ISM band. The laptop used was equipped with a D-Link RangeBooster N USB adapter (model DWA-142), which is a two-antenna 802.11n draft-compliant WLAN client. The main software used for the throughput measurements was Iperf-open source © 2009 by Taylor & Francis Group, LLC Measuring Performance of 3GPP LTE Terminals Head Phantom LAPTOP with USB adapter + turntable + stand ROUTER + stand WLAN link to measure DIRECTION OF DATA FLOW Laptop Router power Ethernet power cable cable cable CONTROL LAPTOP Figure 12.12 Sketch and pictures of measurement setup. software developed by the National Laboratory for Applied Network Research of the United States [56] that can create TCP and UDP data streams and measure network throughput-allowing modification of various parameters for network testing. The first measurements were done to verify the repeatability of the reverbera- tion chamber. The measurements were performed over a 90-s continuous stirring sequence with sampling frequency of two samples per second. This was found to be long enough for a 95% confidence interval for a sample average smaller than 2 Mb/s. Figure 12.13 shows nine consecutive measurements of three channels with good repeatability. This is the first time, as far as we know, that repeatable throughput with this small spread in the results was performed in a rich scattering 