E-UTRA

Abstract: Evolved UTRA and UTRAN is being standardized in 3GPP standard group as a long term evolution of the 3GPP radio-access technology. The goal is to achieve 2-4 times the spectral efficiency and user throughput and much smaller latency compared to HSDPA/HSUPA. Single carrier FDMA (e.g. DFT-SOFDM) is the multiple access technique of choice for uplink transmission. Interference control is one of the key elements to achieve the target spectral efficiency and user cell- edge performance requirement, especially for uplink. In this paper, interference mitigation is implemented through slow fractional power control and interference coordination through UE alignment and FDM resource allocation. Simulation results show that these techniques significantly improve uplink sector and cell edge user throughput performance.

Abstract: Hybrid automatic repeat request (HARQ) is employed for the 3GPP Evolved Universal Terrestrial Radio Access (E-UTRA) downlink. Each user equipment (UE) sends its ACK/NACK corresponding to the downlink data reception to the base station via a physical uplink control channel (PUCCH). The ACK/NACK signals from the UE are first code spread by the cyclic shift sequences, and then spread by the orthogonal cover sequences. The ACK/NACK signals from each UE are multiplexed by means of code division multiple access (CDMA), however, it is difficult for the conventional PUCCH code design to satisfy the required bit error rate (BER) of 10 3 in fast- fading environments because of inter-code interferences among the orthogonal cover sequences. In this paper, we propose a novel PUCCH code design which can suppress the effect of inter-code interferences among the orthogonal cover sequences. And the simulation evaluations confirm that the proposed code design can significantly improve the performance of the ACK/NACK signals via PUCCH especially in fast-fading environments.

Abstract: Embodiments of systems and techniques for coverage adjustment in evolved universal terrain radio access networks (E-UTRANs) are described. In some embodiments, a network management (NM) apparatus may receive data representative of first and second radio link failure (RLF) reports including information related to respective disconnections of first and second user equipment (UEs) from an E-UTRAN. The NM apparatus may identify a hole in a coverage area of the E-UTRAN based at least in part on the first and second RLF reports, and may perform an automated coverage and capacity optimization (CCO) action to reconfigure cell resources of the E-UTRAN based on the identified hole. Other embodiments may be described and claimed.

Abstract: This paper provides a detailed performance comparison between Closed Loop (CL) and Open Loop (OL) MIMO schemes for the upcoming OFDM based mobile broadband radio access technology 3GPP UTRA LTE. Based on system level simulation results, key performance indicators like cell throughput, user throughput and MIMO utilization have been evaluated for different system load conditions assuming 2×2 MIMO in a regular hexagonal cell deployment and in a real network scenario. A realistic dynamic MIMO switch between diversity and spatial multiplexing has been assumed, which is based on configurable CQI as well as rank filtering and decision thresholds. 3GPP compliant measurement granularity as well as appropriate measurement errors have been applied to both CQI and closed loop PMI reports. Besides dynamic MIMO switching, both MIMO 2×2 diversity and MIMO 2×2 spatial multiplexing scenarios have been investigated for the downlink direction highlighting the differences of the various MIMO transmission modes and their impacts on spectral efficiency and radio performance. It has been shown that ideal closed loop MIMO provides a 2 dB theoretical performance gain over open loop MIMO. Assuming practical limitations such as available granularity, delay and realistic PMI measurement errors, however, this gain significantly decreases below roughly 1 dB. Nevertheless MIMO proves to be an appropriate method to boost user throughput especially at low to medium system load up to a factor of 2. Moreover the dynamic MIMO switch proves to be very robust against variations of parameter settings.