Method of determining transmission direction, and a radio system

Abstract

The invention relates to a radio system and a method of determining the transmission direction. The radio system comprises at least one base station communicating with terminals within its area by emitting a radiation pattern extending over the whole cell area and directional radiation patterns covering only part of the cell area. The base station transmits base-station-related information on a common control channel to the terminals. In the solution of the invention, the base-station-related information transmitted by the base station comprises a general part and a beam-specific part. The base station uses the radiation pattern extending over the whole cell area when transmitting the general part. Each beam-specific part is transmitted by using a specific radiation pattern. The terminal detects one of more beam-specific parts from the information received from the base station and transmits information about the detection result to the base station, on the basis of which the base station decides which directional radiation pattern to use when communicating with the terminal. The invention enables fast determination of the terminal direction with respect to the base station.