Method for allocating radio communication resources and network unit associated with a multi-carrier radio communication system
Radio communication resources are allocated in a cellular radio communication system having a plurality of user stations and network units by subdividing a frequency band that is sub-divided into a plurality of sub-carriers used for communication purposes. In several radio cells, one or more network units sub-divides(s) the frequency band into a number of sub-bands having one or more respective sub-carriers, sub-divide(s) the user stations into a number of groups and allocate(s) a sub-band for communication purposes to each group. The number of sub-bands differs for at least two radio cells.
1 - 12 . (canceled)
13 . A method for allocating radio communication resources in radio cells of a cellular radio communication system having a plurality of user stations and network units, comprising:
dividing a frequency band into a plurality of sub-carriers used in the radio communication system for communication purposes, by dividing the frequency band into a number of sub-bands, each sub-band including at least one sub-carrier, so that the number of the sub-bands is different in at least two of the radio cells;
dividing the user stations into a number of groups; and
allocating each group of the user stations to one of the sub-bands for communication.
14 . A method in accordance with claim 13 , further comprising determining the number of sub-bands depending on transmission conditions in each of the at least two radio cells.
15 . A method in accordance with claim 14 , wherein the transmission conditions are transmission capacities of the at least one sub-carrier in each of the radio cells.
16 . A method in accordance with claim 15 , further comprising determining the transmission conditions by at least one of at least one user station and at least one network unit based on measured signal-to-noise ratios.
17 . A method in accordance with claim 13 , wherein said determining of the number of sub-bands for each of the at least two radio cells takes into consideration data transmission made possible subsequently by said dividing of the frequency band into sub-bands, said dividing of the user stations into groups and said allocating of each group to the one of the sub-bands.
18 . A method in accordance with claim 13 , wherein said dividing into the sub-bands and the groups and said allocating of each group to the one of the sub-bands comprises in order to increase transmission capacity:
starting from the transmission capacity of an initial constellation of said dividing into the sub-bands and the groups and said allocating of each group to the one of the sub-bands; and
calculating the transmission capacity of a modified constellation of said dividing into the sub-bands and the groups and said allocating of each group to the one of the sub-bands.
19 . A method in accordance with claim 18 , further comprising forming the modified constellation from the initial constellation by at least one of
swapping at least one user station of a first group with at least one other user station of a second group while said dividing into the sub-bands said allocating of each group to the one of the sub-bands remains unchanged; and
swapping at least one sub-carrier of a first sub-band with at least one other sub-carrier of a second sub-band while said dividing into the groups and said allocating of each group to the one of the sub-bands remains unchanged.
20 . A method in accordance with claim 18 , wherein said determining of the number of sub-bands for each of the at least two radio cells achieves at least one of a predetermined increase in the transmission capacity and a predetermined transmission capacity in the at least two radio cells.
21 . A method in accordance with claim 13 , further comprising, after said allocating of each group to the one of the sub-bands, spreading data using codes on at least some sub-carriers of the one of the sub-bands.
22 . A method in accordance with claim 13 , wherein signals transmitted after said allocating of each group to the one of the sub-bands on at least partly same sub-carriers, can be distinguished from each other by spatial propagation thereof.
23 . A network unit for a radio cell of a cellular radio communication system having a plurality of user stations, and a frequency band divided into a plurality of sub-carriers being used in the radio communication system for communication, said network unit comprising:
means for defining a number of sub-bands depending on transmission conditions in the radio cell;
means for dividing the frequency band into the number of sub-bands each having at least one sub-carrier;
means for dividing user stations into a number of groups; and
means for allocating each group to one of the sub-bands.
24 . A computer readable medium storing a program that when executed controls a network unit for a radio cell of a cellular radio communication system, having a plurality of user stations, to perform a method comprising:
defining a number of sub-bands depending on transmission conditions in the radio cell;
dividing the frequency band into the number of sub-bands each having at least one sub-carrier,
dividing user stations into a number of groups; and
allocating each group to one of the sub-bands.