Abstract: A radio communication system (10) is disclosed which comprises a base station (12) for transmitting and receiving signals to and from one or more remote stations (16). The base station (12) is provided with at least one receive antenna (14) coupled to a base station receiver. The receive antenna (14) is provided with a directional pattern in a horizontal plane and a mechanism for steering the directional pattern azimuthly, until such time as a synchronization signal transmitted by a remote station located within the coverage area is received by the base station receiver. Upon detection of the synchronization signal, scanning of the receive antenna's pattern is stopped until such time as message information can be obtained from the remote station (16) and forwarded to a particular destination requested by the remote station. Upon receiving the information, the base station (12) will resume scanning of the antenna (14), and the information will be forwarded to its requested destination.

Abstract: A base station antenna arrangement comprising a plurality of antenna arrays each capable of forming a multiplicity of separate overlapping narrow beams in azimuth, the arrays being positioned such that the totality of beams formed by the arrays provides a substantially omni-directional coverage in azimuth, azimuth and elevation beamforming means for each array, a plurality of r.f. transceivers each for transmitting and receiving r.f. signals for one or more calls, switching matrix means for connecting each transceiver with one or other of the arrays via the beamforming means, control means for controlling the switching matrix means whereby a particular transceiver is connected to a particular array via the beamforming means to exchange r.f. signals with a remote station located in the area covered by one of the narrow beams.

Abstract: An antenna arrangement (10) for a cellular radio base station is provided with a plurality of r.f. transceivers, including one or more antenna arrays (12) each comprising a plurality of sub-arrays (20) each selectively operpable to form a beam in azimuth. Each sub-army is provided with elevation beamforming means (24) and individual transmit and receive amplifiers (30,32). Each sub-array beamformer is coupled to at least one r.f. transmitter feed (26)nd each r.f. receiver feed is coupled to at least two sub-array beamformers, the sub-arrays of each antenna array together forming a multiplicity of separate substantially coincident beams in azimuth. A method of operation is also disclosed.

Abstract: An antenna for a base station comprising a plurality of antenna arrays (40; FIG. 6a) each capable of forming a multiplicity of separate overlapping narrow beams in azimuth, the arrays being positioned such that the beams formed by the arrays provide a coverage in azimuth wider than each array. Means are provided for splitting (58; FIGS. 14b,14c) the transmission output of a given transceiver into two signals prior to transmission power amplification and transmitting said signals in two adjacent narrow overlapping beams.

Abstract: An adaptive filter may be realized by weighting the outputs from a tapped delay line. This, however, allows nulls to corrupt a wanted signal spectral region. A fixed (non-adaptive) filter (2) coupled between the signal input and an input of means (3) for summing the weighted outputs serves to allow nulls only to be formed in the skirt region of the fixed filter response thus preserving a wanted signal.