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The 3GPP LTE standard for mobile broadband includes multi-antenna transmission modes that improve performance, both in terms of coverage, spectral efficiency and peak throughput. The antenna system design, both at the eNB and at the UE is critical to a well performing system; it should be designed with the intended performance profile in mind. Field trials were performed in order to investigate the relative performance of several four and two transmit antenna setups in an LTE system. In general, multi-antenna technology gave substantial performance gains over single antenna transmission. A closely spaced co-polarized configuration gave the best performance for users with poor channel quality while dualpolarized and well-spaced antenna configurations gave better performance for users with good channel quality. The trial also shows that UE antenna polarization is an important parameter that must be kept in mind when designing the eNB antenna system.

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Interference cancellation (IC) is one identified key technology to enhance WCDMA uplink performance. The goal of this contribution is to highlight the relative uplink system capacity improvement available for WCDMA, especially in realistic typical urban radio environments when employing receiver implementations including realistic channel estimation, searcher, and so forth. The performance of the selected limited-complexity parallel IC receiver is first evaluated with link-level simulations in order to provide input to system-level simulations. The system-level methodology is explained and a 40% system-level uplink capacity increase compared to utilizing the conventional RAKE receiver is found. The limited-complexity parallel IC receiver is then evaluated in a single-cell field trial. The trials show that both the mean and the variance of the outer-loop power control is reduced, which implies an overall increased capacity and an increased battery life of the terminals. Furthermore, the observed capacity gains are in accordance with system simulations.