Erik G. Larsson

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Multiple-input multiple-output (MIMO) technology is maturing and is being incorporated into emerging wireless broadband standards like long-term evolution (LTE) [1]. For example, the LTE standard allows for up to eight antenna ports at the base station. Basically, the more antennas the transmitter/receiver is equipped with, and the more degrees of freedom(More)
This paper addresses energy-efficient design for uplink multiuser SIMO frameworks with marked channel state data (CSD) at the base station (BS). Since the CSD at the BS is constantly unreliable because of the channel estimation error and delay, the imperfectness of the CSD needs to be considered in practical framework plan. It causes interuser impedance at(More)
Basically, the more antennas the base station (and terminal) are equipped with, the better performance in all these four respects. MIMO technology for wireless communications in its conventional form is maturing, and being incorporated into recent and evolving wireless broadband standards like 4G LTE and LTE-advanced. For example, the LTE standard allows(More)
In this correspondence, we study the achievable rate region of the multiple-input single-output (MISO) interference channel, under the assumption that all receivers treat the interference as additive Gaussian noise. Our main result is an explicit parametrization of the Pareto boundary for an arbitrary number of users and antennas. The parametrization(More)
We consider the problem of coordinating two competing multiple-antenna wireless systems (operators) that operate in the same spectral band. We formulate a rate region which is achievable by scalar coding followed by power allocation and beamforming. We show that all interesting points on the Pareto boundary correspond to transmit strategies where both(More)
The ever-increasing demand for higher data rates in wireless communications in the face of limited or underutilized spectral resources has motivated the introduction of cognitive radio. Traditionally, licensed spectrum is allocated over relatively long time periods and is intended to be used only by licensees. Various measurements of spectrum utilization(More)
This paper considers multicell multiuser MIMO systems with very large antenna arrays at the base station. We propose an eigenvalue-decomposition-based approach to channel estimation, that estimates the channel blindly from the received data. The approach exploits the asymptotic orthogonality of the channel vectors in very large MIMO systems. We show that(More)
Space–time coding (STC) schemes for communication systems employing multiple transmit and receive antennas have recently been attracting increased attention. The so-called orthogonal space–time block codes (OSTBCs) have been of particular interest due to their good performance and low decoding complexity. In this paper, we take a systematic(More)
We investigate an orthogonal frequency-division multiplexing (OFDM)-based downlink transmission scheme for large-scale multi-user (MU) multiple-input multiple-output (MIMO) wireless systems. The use of OFDM causes a high peakto-average (power) ratio (PAR), which necessitates expensive and power-inefficient radio-frequency (RF) components at the base(More)