Abstract: The present invention is directed to a method of controlling a communications link and apparatus configured to perform this method. This invention is particularly related to but in no way limited to MIMO (multiple inputs multiple outputs) wireless communications systems. The method comprises the steps of determining at the receiver the quality of the communications link and based on this, selecting a group of transmission parameters and an element from this group. These selections are then communicated to the transmitter. The transmission parameter may be the transmission configuration such as the modulation and coding scheme. The invention minimizes the required feedback signalling from the receiver to the transmitter by exploiting temporal correlation of the parameter being controlled, while allowing rapid selection of the parameter.

Abstract: The present invention is directed to a method of controlling a communications link and apparatus configured to perform this method. This invention is particularly related to but in no way limited to MIMO (multiple inputs multiple outputs) wireless communications systems. The method comprises the steps of determining at the receiver the quality of the communications link and based on this, selecting a group of transmission parameters and an element from this group. These selections are then communicated to the transmitter. The transmission parameter may be the transmission configuration such as the modulation and coding scheme. The invention minimizes the required feedback signalling from the receiver to the transmitter by exploiting temporal correlation of the parameter being controlled, while allowing rapid selection of the parameter.

Abstract: The present invention is directed to a method of controlling a communications link and apparatus configured to perform this method. This invention is particularly related to but in no way limited to MIMO (multiple inputs multiple outputs) wireless communications systems. The method comprises the steps of determining at the receiver the quality of the communications link and based on this, selecting a group of transmission parameters and an element from this group. These selections are then communicated to the transmitter. The transmission parameter may be the transmission configuration such as the modulation and coding scheme. The invention minimizes the required feedback signaling from the receiver to the transmitter by exploiting temporal correlation of the parameter being controlled, whilst allowing rapid selection of the parameter.

Abstract: The present invention is directed to a method of controlling a communications link and apparatus configured to perform this method. This invention is particularly related to but in no way limited to MIMO (multiple inputs multiple outputs) wireless communications systems. The method comprises the steps of determining at the receiver the quality of the communications link and based on this, selecting a group of transmission parameters and an element from this group. These selections are then communicated to the transmitter. The transmission parameter may be the transmission configuration such as the modulation and coding scheme. The invention minimises the required feedback signalling from the receiver to the transmitter by exploiting temporal correlation of the parameter being controlled, whilst allowing rapid selection of the parameter.

Abstract: The present invention is directed to a method of controlling a communications link and apparatus configured to perform this method. This invention is particularly related to but in no way limited to MIMO (multiple inputs multiple outputs) wireless communications systems. The method comprises the steps of determining at the receiver the quality of the communications link and based on this, selecting a group of transmission parameters and an element from this group. These selections are then communicated to the transmitter. The transmission parameter may be the transmission configuration such as the modulation and coding scheme. The invention minimises the required feedback signalling from the receiver to the transmitter by exploiting temporal correlation of the parameter being controlled, whilst allowing rapid selection of the parameter.

Abstract: The present invention is directed to a method of controlling a communications link and apparatus configured to perform this method. This invention is particularly related to but in no way limited to MIMO (multiple inputs multiple outputs) wireless communications systems. The method comprises the steps of determining at the receiver the quality of the communications link and based on this, selecting a group of transmission parameters and an element from this group. These selections are then communicated to the transmitter. The transmission parameter may be the transmission configuration such as the modulation and coding scheme. The invention minimises the required feedback signalling from the receiver to the transmitter by exploiting temporal correlation of the parameter being controlled, whilst allowing rapid selection of the parameter.

Abstract: The present invention is directed to a method of controlling a communications link and apparatus configured to perform this method. This invention is particularly related to but in no way limited to MIMO (multiple inputs multiple outputs) wireless communications systems. The method comprises the steps of determining at the receiver the quality of the communications link and based on this, selecting a group of transmission parameters and an element from this group. These selections are then communicated to the transmitter. The transmission parameter may be the transmission configuration such as the modulation and coding scheme. The invention minimizes the required feedback signalling from the receiver to the transmitter by exploiting temporal correlation of the parameter being controlled, while allowing rapid selection of the parameter.

Abstract: The invention is directed to a method of synchronising transmission between two nodes in a wireless network. The method comprises the steps of obtaining an expected interference profile for each node; and agreeing a synchronised transmission schedule between the nodes, where the expected interference profile of each node meets predetermined criteria.

Abstract: The present invention is directed to a method of controlling a communications link and apparatus configured to perform this method. This invention is particularly related to but in no way limited to MIMO (multiple inputs multiple outputs) wireless communications systems. The method comprises the steps of determining at the receiver the quality of the communications link and based on this, selecting a group of transmission parameters and an element from this group. These selections are then communicated to the transmitter. The transmission parameter may be the transmission configuration such as the modulation and coding scheme. The invention minimises the required feedback signalling from the receiver to the transmitter by exploiting temporal correlation of the parameter being controlled, whilst allowing rapid selection of the parameter.

Abstract: The present invention relates to communication systems and in particular relates to the time alignment of uplink CDMA signals. A simple approach for improving the performance of received CDMA signals is discussed. This consists of aligning the timings of users' signals such that the maximum output power from a single rake finger for each user occurs simultaneously. This allows the timing to be adjusted for each user's signal independently of the others and has the effect of minimizing any interference between users. The invention provides a time alignment mechanism which employs a minimum of signalling.

Abstract: In a cellular radio communications system, using for example spread-spectrum communication, handoff between signals in different cells or in different sectors of sectored cells can be used to provide diversity reception at a mobile station and at cell sites and so to improve the reliability of data decoding. In sectored cells the diversity between signals in adjacent sectors can be low if the fading of the signals is correlated. The invention thus improves diversity gain by prioritising handoff between sectors or cells providing or expected to provide greater signal diversity over handoff between sectors providing or expected to provide less signal diversity, such as between adjacent sectors in sectored cells. Signals are therefore selected for diversity combining on the basis of both signal strength and signal diversity.

Abstract: A conventional antenna 114 at a cell site of a sectored cell in a cellular radio communications system has a low angle of coverage in elevation and therefore has low gain for close-in subscriber units (near the cell site). In a sectored cell, a main beam antenna in a first sector generates sidelobes and backlobes which may fall within the close-in area in other sectors. A close-in mobile in one of the other sectors may move into such an out-of-sector lobe and cause unexpected interference to the base station transceiver (BTS) of the first sector. A downward-looking antenna (DIA) 110 supplements the conventional antenna in each sector and has a beam 112 covering the close-in area. The gain of the DLA beam is greater than that of any out-of-sector lobes and so provides a subscriber unit with a higher gain link to the BTS of its own sector than is provided by out-of-sector lobes to the BTS of any other sector.