Multi-beam cellular communication system
First Claim
1. A method for use in a cellular communication system, the cellular communication system comprising at least one base station serving a plurality of sectors, the at least one base station comprising an antenna arrangement per base station sector for generating an array of narrow beams covering the base station sector,the method comprising the steps of, at the antenna arrangements:
- simultaneously transmitting timeslots over each narrow beam generated by the antenna arrangements;
generating multiple codes in each time slot, the codes being divided into a first sub-set and a second sub-set, the first sub-set and second sub-set being exclusive of one another;
transmitting common overhead channels including a pilot channel to end user equipments on each beam in a sector using the same first sub-set of codes; and
transmitting different data traffic to end user equipments on different beams in a sector by re-using the same second sub-set of codes in each beam.
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0 Petitions
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.
50 Citations
41 Claims
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1. A method for use in a cellular communication system, the cellular communication system comprising at least one base station serving a plurality of sectors, the at least one base station comprising an antenna arrangement per base station sector for generating an array of narrow beams covering the base station sector,
the method comprising the steps of, at the antenna arrangements: -
simultaneously transmitting timeslots over each narrow beam generated by the antenna arrangements; generating multiple codes in each time slot, the codes being divided into a first sub-set and a second sub-set, the first sub-set and second sub-set being exclusive of one another; transmitting common overhead channels including a pilot channel to end user equipments on each beam in a sector using the same first sub-set of codes; and transmitting different data traffic to end user equipments on different beams in a sector by re-using the same second sub-set of codes in each beam. - View Dependent Claims (2, 3, 4, 5, 6, 7)
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8. A cellular communication system comprising:
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at least one base station serving a plurality of sectors, the at least one base station comprising an antenna arrangement per base station sector, each of said antenna arrangements having a beamforming device for generating an array of narrow beams covering the corresponding base station sector, said beamforming devices being arranged to simultaneously transmit timeslots over each of said narrow beams, said timeslots each being split into multiple codes, the codes being divided into a first sub-set and a second sub-set, the first sub-set and second sub-set being exclusive of one another, wherein the at least one 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 first 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 second sub-set codes in each beam. - View Dependent Claims (9, 10, 11, 12, 13, 14)
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15. A non-transitory computer readable medium for installation on a base station controlling device of a cellular communication system for controlling a base station serving a plurality of sectors, the base station comprising an antenna arrangement per base station sector for generating an array of narrow beams covering the plurality of sectors, 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, the codes being divided into a first sub-set and a second sub-set, the first sub-set and second sub-set being exclusive of one another;
- in which the non-transitory computer readable medium is encoded with instructions which when executed by a processor in the base station controlling device causes the base station, in each sector, to perform the following steps of;
allocating the same first sub-set of codes in each timeslot of a set of timeslots to common overhead channels including a pilot channel; and
allocating the second 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)
- in which the non-transitory computer readable medium is encoded with instructions which when executed by a processor in the base station controlling device causes the base station, in each sector, to perform the following steps of;
- 21. A base station of a cellular communication system, the base station arranged to serve a plurality of sectors, the base station comprising an antenna arrangement per base station sector, each of said antenna arrangements has a beamforming device for generating an array of narrow beams covering the base station sector corresponding to that antenna arrangement and for transmitting timeslots simultaneously over each of said narrow beams, said timeslots being each split into multiple codes, the codes being divided into a first sub-set and a second sub-set, the first sub-set and second sub-set being exclusive of one another, wherein the 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 first sub-set of codes and to transmit different data traffic to end user equipments on different beams in a sector by reusing the same second sub-set of codes in each beam.
- 28. A base station of a cellular communication system comprising at least one antenna arrangement for generating an array of narrow beams for covering a sector, the base station being arranged to simultaneously transmit different data traffic signals to end user equipments on each beam of the sector by re-using a same set of codes such that an end user equipment located in the sector discriminates between the beams only by the spatial separation of the beams in the sector, wherein the base station also 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 the same data traffic to that end user equipment on at least two adjacent beams of the sector using the same codes.
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31. A non-transitory computer readable medium for installation on a base station of a cellular communication system, the base station comprising at least one antenna arrangement for generating an array of narrow beams for covering a sector and wherein the base station is arranged to simultaneously transmit different data traffic signals to end user equipments on each beam of the sector by re-using a same set of codes such that an end user system equipment located in the sector discriminates between the beams only by the spatial separation of the beams in the sector, wherein the non-transitory computer readable medium is encoded with instructions which when executed by a processor in the base station causes the base station to perform the following steps of:
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determining when an end user equipment is located in a high interference region between two adjacent beams; and in response to such a determination simultaneously scheduling the same data traffic to that end user equipment on at least two adjacent beams of the sector using the same codes. - View Dependent Claims (32, 33)
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34. A method for use in a base station of a cellular communication system, the base station comprising at least one antenna arrangement for generating an array of narrow beams 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, comprising the steps of, at the at least one antenna arrangement:
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simultaneously transmitting timeslots over each beam generated by the antenna arrangement; generating a set of multiple codes in each time slot; using the same set of codes in each beam and dividing the codes to be used for data traffic transmission into differently sized sub-sets of codes by a code boundary, with the position of the code boundary being different for adjacent beams; and simultaneously transmitting different data traffic packets to end user equipments on each beam using each of the sub-sets of codes to form a data traffic packet. - View Dependent Claims (35, 36, 37)
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- 38. A base station of a cellular communication system, the base station comprising at least one antenna arrangement for generating an array of narrow beams 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 antenna arrangement also arranged to simultaneously transmit timeslots over each beam, and the base station further comprising a scheduling device for generating a set of multiple codes in each time slot and for dividing the codes to be used for data traffic transmission into differently sized sub-sets of codes by a code boundary, with the position of the code boundary being different for adjacent beams, the scheduling device being further arranged for simultaneously scheduling different data traffic packets on each beam using each of the sub-sets of codes to form a data traffic packet, the same set of codes being used in each beam.
Specification