Multi-beam cellular communication system
First Claim
1. A method for use in a cellular communication system comprising at least one base station (2) the or each of which comprises an antenna arrangement (4, 6, 8) per base station sector for generating an array of narrow beams (10, 12, 14) covering the sector, which method comprising the steps of:
- simultaneously transmitting timeslots over each beam;
generating multiple codes in each time slot;
transmitting common overhead channels including a pilot channel to end user equipments on each beam in a sector using the same sub-set of codes, and transmitting different data traffic to end user equipments on different beams in a sector by re-using the same codes in each beam.
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Accused Products
Abstract
A cellular communication system comprising a plurality of geographically spaced base stations (2) each of which comprises an antenna arrangement (4, 6, 8) per base station sector, each of which antenna arrangements has an antenna element for generating an array of narrow beams (10, 12, 14) covering the sector. Timeslots are simultaneously transmitted over each of the beams so as to generate successive sets of simultaneously transmitted timeslots per sector. The timeslots are each split into multiple orthogonal codes, for example Walsh codes. The communication system additionally comprising a scheduling device (31) for allocating for successive sets of timeslots common overhead channels, including a common pilot channel, which are allocated to the same sub-set of codes of each timeslot in the set. For successive sets of timeslots different data traffic is allocated to the same sub-set of codes of each timeslot in the set. This effectively generates a sector wide antenna beam carrying the common overhead channels and a plurality of narrow beams each of which carry different data traffic. Inter-beam interference is addressed by the application of Adaptive Modulation and Coding and by an inter-beam handoff scheme. The handoff scheme ensures that when an end user equipment is located in a cusp region between adjacent beams the antenna arrangement simultaneously transmits data traffic to that mobile station on at least both of the adjacent beams.
93 Citations
44 Claims
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1. A method for use in a cellular communication system comprising at least one base station (2) the or each of which comprises an antenna arrangement (4, 6, 8) per base station sector for generating an array of narrow beams (10, 12, 14) covering the sector, which method comprising the steps of:
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simultaneously transmitting timeslots over each beam;
generating multiple codes in each time slot;
transmitting common overhead channels including a pilot channel to end user equipments on each beam in a sector using the same sub-set of codes, and transmitting different data traffic to end user equipments on different beams in a sector by re-using the same codes in each beam. - View Dependent Claims (2, 3, 4, 5, 6, 7)
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- 8. A cellular communication system comprising at least one base station (2) the or each of which comprises an antenna arrangement (4, 6, 8) per base station sector, each of which antenna arrangements having a beamforming device for generating an array of narrow beams (10, 12, 14) covering the sector, over each of which beams timeslots are simultaneously transmitted which timeslots are each split into multiple codes, wherein the or each base station is arranged to transmit common overhead channels including a pilot channel to end user equipments in each beam in a sector using the same sub-set of codes and to transmit different data traffic to end user equipments on different beams in a sector by re-using the same codes in each beam.
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15. Computer readable media for installation on a base station controlling device of a cellular communication system for controlling a base station (2) which comprises an antenna arrangement (4, 6, 8) per base station sector for generating an array of narrow beams (10, 12, 14) covering the sector, in which each antenna arrangement simultaneously transmits timeslots over each beam to generate successive sets of simultaneously transmitted timeslots and in which each time slot is split into multiple codes;
- which computer readable media carries out the steps of
allocating the same sub-set of codes in each timeslot of a set of timeslots to common overhead channels including a pilot channel; and
allocating a sub-set of codes in each timeslot of a set of timeslots to different data traffic so as to transmit different data traffic on different beams by re-using the same codes in each beam. - View Dependent Claims (16, 17, 18, 19, 20)
- which computer readable media carries out the steps of
- 21. A base station of cellular communication system comprising an antenna arrangement (4, 6, 8) per base station sector, each of which antenna arrangements has a beamforming device for generating an array of narrow beams (10, 12, 14) covering the sector, over each of which beams timeslots are simultaneously transmitted which timeslots are each split into multiple codes, wherein each base station is arranged to transmit common overhead channels including a pilot channel to end user equipments in each beam in a sector using the same sub-set of codes and to transmit different data traffic to end user equipments on different beams in a sector by re-using the same codes in each beam.
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28. A handoff method for use in a base station of a cellular communication system comprising at least one antenna arrangement (4, 6, 8) for generating an array of narrow beams (10, 12, 14) for covering a sector wherein an end user equipment located in the sector discriminates between the beams in the sector only by the spatial separation of the beams and in which different data traffic signals are simultaneously transmitted to end user equipments on each beam, comprising the steps of:
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determining when an end user equipment (1) is located in a high interference region between two adjacent beams; and
in response to such a determination simultaneously transmitting data traffic to that end user equipment on at least two beams of the sector. - View Dependent Claims (29, 30)
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- 31. A base station of a cellular communication system comprising at least one antenna arrangement (4, 6, 8) for generating an array of narrow beams (10, 12, 14) for covering a sector wherein an end user equipment located in the sector discriminates between the beams only by the spatial separation of the beams in the sector and in which different data traffic signals are simultaneously transmitted to end user equipments on each beam, wherein the base station includes a processing device for determining when an end user equipment is located in a high interference region of the sector and the base station includes a scheduling device which in response to such a determination simultaneously schedules data traffic to that end user equipment on at least two beams of the sector.
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34. Computer readable media for installation on a base station of a cellular communication system comprising at least one antenna arrangement (4, 6, 8) for generating an array of narrow beams (10, 12, 14) for covering a sector wherein an end user system located in the sector discriminates between the beams only by the spatial separation of the beams in the sector and in which different data traffic signals are simultaneously transmitted to and user equipments on each beam, wherein the computer readable media carries out the steps of:
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determining when an end user equipment (1) is located in a high interference region between two adjacent beams; and
in response to such a determination simultaneously scheduling data traffic to that end user equipment on at least beams of the sector. - View Dependent Claims (35, 36)
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37. A method for use in a base station of a cellular communication system comprising at least one antenna arrangement (4, 6, 8) for generating an array of narrow beams (10, 12, 14) for covering a sector wherein an end user system located in the sector discriminates between the beams in the sector only by the spatial separation of the beams, comprising the steps of:
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simultaneously transmitting different data traffic packets to end user equipments on each beam, and simultaneously transmitting data traffic packets of different lengths on adjacent beams. - View Dependent Claims (38, 39, 40)
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- 41. A base station of a cellular communication system comprising at least one antenna arrangement (4, 6, 8) for generating an array of narrow beams (10, 12, 14) for covering a sector wherein an end user system located in the sector discriminates between the beams only by the spatial separation of the beams in the sector, the base station comprising a scheduling device for simultaneously scheduling different data traffic packets on each beam and for simultaneously scheduling data traffic packets of different lengths on adjacent beams.
Specification