US 5,966,670 A · Method for transmitting a pilot signal, and a cellular radio system

Abstract

In a cellular radio system having in each of a plurality of cells at least one base station communicating with mobile stations located within its area, the base stations each transmit a pilot signal to the mobile stations. At least one of the base stations, transmits to the mobile stations by transmitting a pilot signal by using a rather narrow changing antenna beam. The angle of the greatest gain of the antenna beam is controlled in such a way that the antenna beam sweeps the cell area. The mobile stations can use the pilot signal in the identification of a base station, and as an indicator of a need for handover, without the continuous reception of the pilot signal in the subscriber equipment, and without a need to transmit the pilot signal with a higher transmission power than the other signals.

Claims12

Dependent claims

A method for transmitting a pilot signal in a cellular radio system, which has in each of a plurality of cells at least one base station communicating with mobile stations located within a respective cell area, comprising:

said base stations each transmitting a data signal in a downlink transmission direction by using radiation patterns that change in time;
said base stations each transmitting a respective pilot signal on a respective common control channel to respective mobile stations;
in transmitting said respective pilot signal, each base station using at least one narrow, changing antenna beam having an angle of greatest gain;
and
each base station, in transmitting said respective pilot signal, directing said angle of greatest gain of each respective antenna beam in such a way that said respective antenna beam sweeps said respective cell areas the sweeping of the beam is synchronized to a frame structure of each said base station.

2 more elements

A cellular radio system, comprising:

in each of a plurality of cells, there being at least one base station arranged for communicating with a plurality of respective mobile stations located within a respective cell area;
said base stations each being arranged to transmit a respective pilot signal on a common control channel to said respective mobile stations;
at least one of said base stations being arranged to transmit to said respective mobile stations using radiation patterns that change in time;
said at least one base station comprising a transmitter. which transmits said respective pilot signal as at least one narrow, changing antenna beam having an angle of greatest gain;
and
each said at least one said base station including a controller, which controls said respective angle of greatest gain of each respective said antenna beam in such a way that said respective antenna beam sweeps said respective cell area, the sweeping of the antenna beam is synchronized to a frame structure of each said at least one said base station.

3 more elements

Dependencies are inferred from the claim text.

Method for transmitting a pilot signal, and a cellular radio system

Life of this patent

Method for transmitting a pilot signal, and a cellular radio system

Life of this patent

Abstract

Claims12