US 6,330,459 B1Granted

Communication system with a beamformed control channel and method of system control

AssigneeMotorola, Inc.

InventorsPaul Crichton, Paul Howard, Nicholas Anderson, William Robinson

Life of this patent

Estimating the term…

Loading patent…

Abstract

To reduce interference in a communication system (10), a communication unit (42-50) is arranged to initiate establishment of a radio frequency communication with a base station (26-38) by transmitting a system access request on a dedicated, wide area control channel. Upon receipt of the system access request, a base station (32) of the communication system of FIG. 1 responds by forming a narrowbeam control channel to the communication unit and transmitting system control information to the communication unit on the narrowbeam control channel, the system control information transmitted from the array of antenna elements and arranged to identify a narrowbeam communication resource for use in the radio communication. The communication unit (42-50), upon receiving the system control information, then configures itself to utilise the narrowbeam communication resource for the radio communication.

Claims8

Dependent claims

A method of establishing radio communication between a communication unit and a base station having an array of antenna elements, the method comprising the steps of:

receiving a system access request at each base station of a plurality of base stations, wherein each base station of the plurality of base stations comprises an antenna array;
making signal parameter measurements of the access request received by each base station of the plurality of base stations;
determining a rank order of signal parameter measurements with respect to the plurality of base stations;
selecting a base station to serve the communication unit based on the rank order to produce a serving base station;
at the serving base station, in response to the received system access request, forming a first narrowbeam control channel to the communication unit and transmitting system control information to the communication unit on the first narrowbeam control channel, the system control information transmitted from the array of antenna elements and arranged to identify a narrowbeam communication resource for use in the radio communication;
at the serving base station, receiving a request for assignment of a new narrowbeam control channel;
in response to the request for assignment of a new narrowbeam control channel, instructing at least one non-serving base station of the plurality of base stations to prepare to transmit narrowbeam control channels at the communication unit;
at the at least one non-serving base station of the plurality of base stations, in response to receiving an instruction to prepare to transmit, notifying the serving base station of channel assignment information pertaining to a subsequent transmission of the narrowbeam control channels at the communication unit;
and
at the serving base station, in response to receiving the channel assignment information from the at least one non-serving base station, notifying the communication unit of the channel assignment information on the first narrowbeam control channel.
2.The method of claim 1, further comprising the step of, at the serving base station, periodically altering a beam pattern of the first narrowbeam control channel.

8 more elements

A radio communication system for supporting radio communication between a communication unit and at least one of a plurality of base stations, the system comprising:

a plurality of base stations, wherein each base station of the plurality of base stations comprises:
an array of antenna elements;
a means, responsive to the array of antenna elements, for receiving and processing a system access request;
a means, responsive to the system access request, for assigning and generating system control information identifying a narrowbeam communication resource for use in a radio communication with the communication unit;
a means, coupled to the array of antenna elements, for forming and transmitting a first narrowbeam control channel to the communication unit in response to the received system access request;
a means for making signal parameter measurements of the access request received at each base station of the plurality of base stations;
a means for determining a rank order of signal parameter measurements with respect to the plurality of base stations;
a means for selecting a serving base station to serve the communication unit from the rank order;
a means at the serving base station for receiving a request for assignment of a new narrowbeam control channel;
a means for instructing, in response to the request for assignment of a new narrowbeam control channel, at least one non-serving base station of the plurality of base stations to prepare to transmit narrowbeam control channels at the communication unit;
a means at the at least one non-serving base station of the plurality of base stations for notifying, in response to receiving an instruction to prepare to transmit, the serving base station of channel assignment information pertaining to a subsequent transmission of the narrowbeam control channels at the communication unit;
and
a means at the serving base station for notifying, in response to receiving the channel assignment information from the at least one non-serving base station, the communication unit of the channel assignment information on the first narrowbeam control channel.

10 more elements

Dependencies are inferred from the claim text.