David Astely

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This paper provides a high-level overview of some technology components currently considered for the evolution of LTE, referred to as LTE-Advanced. First, a brief overview of LTE and some of its technologies are given and then the IMT-Advanced requirements are discussed. One of the targets with the evolution of LTE is to reach or seven surpass these(More)
In wireless communication scenarios, multipath propagation from local scatterers in the vicinity of mobile sources may cause angular spreading as seen from a base station antenna array. This paper studies the effects of such local scattering on direction of arrival (DOA) estimation with the MUSIC and ESPRIT algorithms. Previous work has considered rapidly(More)
This document contains a first assessment of spatial transmission schemes regarding performance and complexity. In order to assess advanced beamforming and MIMO technologies, mathematical models, as well as methodologies for simulation and assessment have been developed. Conceptual work and simulation campaigns have been conducted. A baseline WINNER(More)
The problem of spatial signature estimation using a uniform linear array (ULA) with unknown receiver gain and phase responses is studied. Sufficient conditions for identifying the spatial signatures are derived, and a closed-form ESPRITlike estimator is proposed. The performance of the method is investigated by means of simulations and on experimental data(More)
Modern communication systems are often interference limited. By modeling the co-channel interference as spatially colored, temporally white Gaussian noise, it is straightforward to incorporate interference rejection in the metric of a sequence estimator. In general, estimates of both the channels and the spatial color of the co-channel interference and the(More)
In Long Term Evolution (LTE) specification, physical uplink control channel (PUCCH) consists of two basic transmission formats, i.e. formats 1a/1b and format 2, carrying some control signals fed back to eNodeB, e.g. ACK/NACK related to downlink data transmission blocks and downlink channel quality indicator (CQI). At eNodeB, conventional receiver detection(More)
This paper discusses the requirements on future radio access and, based on the requirements, proposes a framework for such a system. The proposed system based on orthogonal frequency-division multiplexing supports very low latencies and data rates up to 100 Mb/s with wide area coverage and 1 Gb/s with local area coverage. Spectrum flexibility is identified(More)