Telefonaktiebolaget Lm Ericsson (publ)

S&ouml;ren Andersson

Sven Oscar Petersson

Fredrik Bengt Ovesj&ouml;

Ulf Forss&eacute;n

Bo Hagerman

Sara Mazur

Bj&ouml;rn Gunnar Johannisson

Henrik Revsbech Dam

Magnus L Berg

Marc Frerich

Felix Ahrens

Rainer Bormann

The present invention relates to radio systems and, more particularly, to a method and apparatus for receiving radio signals with the aid of beams generated by antenna assemblies. For each of the beams in a first of the antenna assemblies there is a beam in the second of the antenna assemblies that covers the same space area. Signals received by the second are delayed relative to signals received by the first of the antenna assemblies. Then signals from the first antenna assembly are combined with signals from the second of the antenna assemblies. The combined signals derive from beams covering the same space area. Each combined signal is then radio received in a joint radio receiver. A DOA-estimation can be calculated on the basis of radio received signals derived from all beams.

Methods and apparatus in antenna diversity systems for estimation of direction of arrival

The present invention relates generally to the problems associated with sectorization of cells in cellular communications systems, and more particularly to interference between sectors. The invention provides the possibility of flexibly distributing hardware between sectors in a cell by allowing one transmitter to be shared by all the sectors. Since a beacon signal must be transmitted to each sector in a cell, it can be combined with the signal from the transmitter before being transmitted from an antenna. Thus it is necessary to only deploy one carrier for the beacon. Interference reduction in sectored sites is also improved. In addition, different antenna patterns may be combined to provide the site with all kinds of coverage patterns. Downlink diversity is furthermore attainable by having overlapping uncorrelated antenna patterns.

Adaptive sectorization

A method and a system for calibrating the reception and transmission of an antenna array for use in a cellular communication system is disclosed. The calibration of the reception of the antenna array is performed by injecting a single calibration signal into each of a number of receiving antenna sections, in parallel. The signals are collected after having passed receiving components that might have distorted the phase and amplitude. Correction factors are generated and applied to received signals. The calibration of the transmission of the antenna array is preformed in a similar way. A single calibration signal is generated and injected into each of a number of transmitting antenna sections, one at a time. The signals are collected, one at a time, after having passed transmitting components that might have distorted the phase and amplitude. Correction factors are generated and applied to signals that are to be transmitted.

Antenna array calibration

To improve null depths in an antenna pattern of a first polarization, formed with nulls in at least one angular region, a further antenna pattern of a second polarization, substantially orthogonal to the first polarization, is concurrently formed. In the angular region, the amplitudes of the copolar components of the further antenna pattern are substantially equal to the amplitudes of the crosspolar components of the antenna pattern of the first polarization, and the phases of the copolar components of the further antenna pattern of the second polarization are substantially opposite to the phases of the crosspolar component of the first polarization.

Method and arrangement for improving null depths

Growing community of inventors

Sollentuna, Sweden

Sören Andersson

Growing community of inventors

Sollentuna, Sweden

S&ouml;ren Andersson

Sören Andersson