Bjorn Ottersten

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Interpolation or mapping of data from a given real array to data from a virtual array of more suitable geometry is well known in array signal processing. This operation allows arrays of any geometry to be used with fast direction-of-arrival (DOA) estimators designed for linear arrays. In an earlier companion paper , a first-order condition for zero DOA bias(More)
This paper analyzes the performance of methods for estimating the parameters of narrowband signals arriving at an array of sensors. The so-called deterministic and stochastic maximum likelihood (ML) methods are considered. A performance analysis is carried out for nite number of snapshots but assuming that the array is composed of a suuciently large number,(More)
Multiple transmitters and receivers can be used to provide high link capacity in future wireless systems. Herein, an analysis of indoor environment MultipleInput-MultipleOutput measurements in the 5.8 GHz band is performed and the possible increase in capacity, utilizing multiple transmitters and receivers i s examined. The investigation shows that in the(More)
This paper investigates the usage of established interference cancellation techniques applied to the simultaneous reception of geostationary satellite broadcast signals from two or more satellites. In particular the reduction of interference from adjacent satellites is of interest, which would allow a reduction of the antenna size and the requirements on(More)
In this letter, we study the diversity unfairness associated with the conventional Tomlinson-Harashima precoding (THP) in multiuser multiple-input multiple-output downlink transmission. A single-retransmission scheme that combines two THP signals at each user with a complementary multi-user suppression order is investigated. For a system with <i>M</i>(More)
A critical step in multi-frame super-resolution is the registration of frames based on their motion. We improve the performance of current state-of-the-art super-resolution techniques by proposing a more robust and accurate registration as early as in the initialization stage of the high resolution estimate. Indeed, we solve the limitations on scale and(More)
This paper introduces a new 1-D model to encode coloured images for an efficient subsequent processing. This representation is equivalent to, but more compact than, the 3-D HCL conical representation. It consists in gathering all the hue, chroma and luminance information in one component, namely, the cumulative spiral angle, where the spirals in question(More)
In this work, a directional modulation-based technique is devised to enhance the security of a multi-antenna wireless communication system employing M -PSK modulation to convey information. The directional modulation method operates by steering the array beam in such a way that the phase of the received signal at the receiver matches that of the intended M(More)