Abstract: A receiver receives signals which are at least partially known and which have followed a plurality of different paths to said receiver. The receiver has an arrangement for dividing the area of coverage of said receiver into a plurality of sections. A plurality of receiving units are provided to process a different one of said signals to identify the at least partially known part of said signal. A controller is coupled to the output of said dividing arrangement for selecting the signals which are to be allocated to the respective receiving units and an interference removing arrangement is coupled to the output of the receiver units to remove interference.

Abstract: A method includes receiving at least two space-time coded signals from an antenna system associated with a first station, determining complex channel state information based on the received space-time coded signals, and sending the complex channel state information to the first station. In an alternative embodiment, a method includes transmitting at least two space-time coded signals in respective beams of a multi-beam antenna array, measuring a channel impulse response for each space-time coded signal at a second station, and sending an indicia of a selected set of least attenuated signals from the second station to the first station. The multi-beam antenna array is associated with a first station. The beams transmit a signature code embedded in each respective space-time coded signal, and the signature codes are orthogonal so that the second station can separate and measure the channel impulse response corresponding to each space-time coded signal.

Abstract: A method includes receiving at least two space-time coded signals from an antenna system associated with a first station, determining complex channel state information based on the received space-time coded signals, and sending the complex channel state information to the first station. In an alternative embodiment, a method includes transmitting at least two space-time coded signals in respective beams of a multi-beam antenna array, measuring a channel impulse response for each space-time coded signal at a second station, and sending an indicia of a selected set of least attenuated signals from the second station to the first station. The multi-beam antenna array is associated with a first station. The beams transmit a signature code embedded in each respective space-time coded signal, and the signature codes are orthogonal so that the second station can separate and measure the channel impulse response corresponding to each space-time coded signal.

Abstract: A multi-user receiver which uses at least two antenna elements and in which the influence of interference is reduced, the receiver comprises: means (200) for pre-filtering a wideband antenna signal, the pre-filtering means being determined on the basis of a spatial covariance matrix estimate, which spatial covariance matrix estimate is obtained from wideband antenna signals by sampling, arranging sampled values into a signal vector and by multiplying the signal vector by its conjugate transpose vector, means (210, 218) for removing the whitening from signals of predetermined users by using an inverse matrix of the matrix used in the whitening filter, means (202, 204, 206, 208, 210) for performing multi-path combining and multi-antenna combining.

Abstract: The invention relates to a base station for a radio communications network. In order to be able to enhance the resolution for a direction of arrival estimation, the base station comprises: a first phasing network (31) for forming beams (B1-B4) for fixed reception angles; a second phasing network (33) for co-phasing and summing the signals of at least two neighbouring beams (B2, B3), thus forming a beam (B2-3) for a reception angle in-between at least those two neighbouring beams (B2, B3), and for scaling each resulting beam (B2-3) with a predetermined factor; and means for estimating the direction of arrival in the uplink from the beams (B1-B4, B2-3) provided by the first and the second phasing network (31, 33). The invention equally relates to a corresponding method and to a base station module comprising such a first and second phasing network.

Abstract: There is disclosed a method and apparatus for determining the channel quality of a transmitted signal in a receiver of a communication system having an adaptive antenna transmitter capable of transmitting at least one narrow beam signal (116, 120) and at least one wide antenna signal (118) comprising; receiving a beam signal; receiving an antenna signal; wherein the received beam and antenna signals each comprise a plurality of multi-path signals, the method further comprising estimating parameters of the received beam signal based on the information received in a first sub-set of the multi-paths of the received antenna signal.

Abstract: The invention relates to a method of allocating radio resources and a telecommunication system including a base station and user equipment. The base station includes a beam forming device configured to form at least two primary beams for signal reception. The antenna array and the beam forming device of the base station are configured to receive a signal transmitted by the user equipment using at least two primary beams, thus providing primary beam-specific signals as output. The base station includes a processing device for determining at least two secondary beam-specific variables associated with two secondary beams using the primary beam-specific signals as input and a transformation between the primary antenna beams and the secondary antenna beams. The telecommunication system further includes an allocation device for allocating radio resources to the user equipment based on the secondary beam-specific variables.

Abstract: The invention relates to a method for transmitting packet data in a radio system, the radio system comprising at least one base station and at least one subscriber terminal and a downlink power control arrangement, in which power control arrangement the quality of a signal transmitted by the base station is evaluated and, on the basis of this evaluation, power control commands are transmitted to the base station. The method comprises analysing (302) the power control commands received by the base station, searching (304) for one or more transmission moments, on the basis of the analysis, that satisfy the set conditions for packet-switched data transmission, and if at least one transmission moment is found that satisfies the set conditions, transmitting (306) packet data to at least one subscriber terminal at least at one transmission moment that satisfies the set conditions.

Abstract: A radio system includes a base station and a remote station. The base station includes a space-time encoder, an antenna system, a transmitter, a base station receiver, and a power management controller. The space-time encoder encodes a stream of symbols into first and second space-time coded signals, and the transmitter transmits the first and second space-time coded signals at respective first and second initial transmit powers from the antenna system so as to form respective first and second radiation patterns. The base station receiver receives power coefficient indicator information from the remote station, and the power management controller determines first and second adjusted transmit powers based on the respective first and second initial transmit powers and the power coefficient indicator information. In an alternative embodiment, a transmit station of a radio system includes a circuit to determine an angular power spectrum, a space-time encoder, and a transmitter.

Abstract: The inventive idea is to send in the same cell on one channel several signals and to cause different radio frequency characteristics to the signals received on the same channel. The different characteristics of signals are brought about e.g. by modulating the signals in different ways or by sending the signals from different points, whereby the different signals will experience different radio channels. Owing to the different characteristics, the signals can be distinguished from one another by a joint detection, interference cancellation method. In the downlink direction from the base transceiver station to the mobile station and in the uplink direction from mobile station to the base transceiver station it is often advantageous to use different methods.

Abstract: A method for determining weight factors of antenna beams, the method comprising using at least one directional antenna beam implemented with an antenna array to establish a radio link, forming a radio cell with the antenna beam, dividing the radio cell into at least two different cells by dividing the antenna beam, selecting weight factors of antenna elements of the antenna array such that the antenna element specific sums of weight factors of a radio cell formed with the antenna array and corresponding weight factors of at least one, second radio cell formed with the same antenna array are at least substantially equal within predetermined limits in order to achieve a predetermined power balance between different antenna elements.

Abstract: The invention relates to a method and a base station of a radio system implementing the method and to an antenna array of the base station which enable both antenna diversity and beam forming using the same antenna array. In the solution described the antenna array comprises, in addition to a linear part configured for beam forming, a non-linear part which is used for forming diversity. Furthermore, the non-linear part enlarges the aperture of the antenna array, thus improving the quality of beam forming.

Abstract: The invention relates to a method of controlling a radio system in a base transceiver station (204), in which base transceiver station (204) at least one antenna array is formed, which comprises at least two antennas (236, 238) for transmitting and receiving a signal, and in which method at least two antennas (236, 238) of each antenna array are arranged in such a way that antenna beams (410, 412) formed by the at least two antennas deviate vertically from each other what it comes to at least one property thereof. The antenna array can be controlled in a desired manner by controlling the ratio of the signal powers supplied to each antenna of the antenna array. The solution of the invention provides for instance flexibility for controlling signal power, which reduces interference in a radio system and increases data transmission capacity in a radio system.

Abstract: A method of directional radio communication between a first station and a second station comprises the steps of transmitting signals from the second station to the first station via a radio channel. At least one parameter indicative of the speed of change in the radio channel is measured. A rate with which the second station should send signals to the first station is determined from the at least one parameter and the second station sends signals to the first station with at least the rate.

Abstract: A method for directing an antenna beam, and a transceiver which comprises antenna arrays forming antenna beams in the transmission direction, by means of which beams a signal is transmitted, and which receives signals that propagate via different paths to the transceiver. The transceiver comprises estimating means for estimating directions of arrival of the received signals, when the transceiver receives signals propagated via different paths, measuring means for measuring the strengths of the signals received from different paths of arrival, and beam directing means. The directing means command the antenna array to form in the transmission direction the main antenna beam which is formed in the direction wherefrom the strongest signal is received, if the directions of arrival of the received signals differ only slightly from one another.

Abstract: A method of forming directional antenna beams, comprising: directing at least two antenna beam signals by means of a beam formation matrix and pre-phasing pre-determined antenna beam signals formed with an antenna array in such a way that the signal of at least one antenna beam has a different phase compared with the signals of other antenna beams. The pre-phasing is implemented with a pre-phasing element, which comprises phasing coefficients in digital implementation. The pre-phasing element is implemented in such a way, for example, that the power of the sum signal of the antenna elements is evenly distributed to the different antenna elements in a pre-determined variation range.

Abstract: The invention relates to a method of estimating a downlink channel in a radio system, and to a radio system. The method comprises transmitting a common pilot signal and a user-specific pilot signal, of which channel estimates are formed. A channel estimate for the user-specific channel that has transmitted the user-specific pilot signal is formed of said channel estimates by selecting an appropriate scaling factor. The quality of the user-specific channel estimation and thus also the performance of the radio system are improved by means of the invention.

Abstract: The invention relates to a method of estimating a downlink channel in a radio system, and user equipment in a radio system. The user equipment is configured to form an impulse response for a common pilot channel transmitted with a wide antenna beam and an impulse response for a beam-specific pilot signal transmitted with a directional narrow antenna beam. The user equipment is further configured to calculate the impulse response of the downlink channel by using the impulse response of the common pilot channel and the impulse response of the beam-specific pilot signal, taking into account the phase difference formed.

Abstract: The invention relates to a base station for a radio communications network. In order to be able to enhance the resolution for a direction of arrival estimation, the base station comprises: a first phasing network (31) for forming beams (B1-B4) for fixed reception angles; a second phasing network (33) for co-phasing and summing the signals of at least two neighbouring beams (B2, B3), thus forming a beam (B2-3) for a reception angle in-between at least those two neighbouring beams (B2, B3), and for scaling each resulting beam (B2-3) with a predetermined factor; and means for estimating the direction of arrival in the uplink from the beams (B1-B4, B2-3) provided by the first and the second phasing network (31, 33). The invention equally relates to a corresponding method and to a base station module comprising such a first and second phasing network.

Abstract: A method and an apparatus for implementing the method for providing transmission of an uninterrupted pilot signal covering the whole antenna sector. The method uses at least two primary pilot signals orthogonal relative to each other in a radio system comprising adjacent directional antenna beams. In the method, primary pilot signals are transmitted in main antenna beams of the antenna pattern in such a way that adjacent main antenna beams have primary pilot signals orthogonal relative to each other, and the widths and directions of the antenna beams are adjusted in such a way that the beams having the same primary pilot signal do not overlap.