Measurement-Based Evaluation of Link Budget Gain from 3GPP LTE Uplink Transmit Antenna Selection

This paper presents a measurement-based evaluation of link budget gain from uplink transmit antenna selection in 3GPP LTE. In contrast to earlier studies, the results are based on channel measurements and realistic non-omnidirectional mobile terminal antennas. Further, in addition to the impact of fast selection based on small-scale fading power, also the gain from slow selection based on average signal power is evaluated. In the evaluated measurement cases, fast and slow fading based transmit antenna selection result in up to $3.7$ and $3.2$ dB average power gain, respectively, with respect to the fixed uplink transmit antenna case. This implies that with practical non-omnidirectional terminal antennas a major portion of the gain can be realized based on slow selection, hence justifying a simple open-loop transmit antenna selection scheme which is also applicable to FDD systems.