Cellular radio communication system, radio base station apparatus and radio terminal unit
AssigneeHitachi, Ltd.
InventorsMikio Kuwahara, Hajime Kanzaki, Kenichi Azuma
Life of this patent
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Abstract
In a cellular radio communication system including of multi-antenna base stations, to make effective use of the reduced interference in supposing the use of beam form and avoid the interference in an adjacent station even if a space multiplex and the beam form are mixed. Frequencies intended for the cell edge in an FFR are classified into frequencies for space multiplex and a frequency for beam form. Thereby, a frequency at which the interference is reduced by the beam form is fixed. A frequency intended for the cell center is in a frequency band and signals are transmitted from three base stations.
Claims17
A cellular radio communication system comprising a radio base station apparatus for making any one of a space multiplex transmission and a beam form transmission using a plurality of antennas and a plurality of radio terminal units, each radio base station apparatus,
- (i) separating communicable frequency band in the cellular radio communication system to:
- a first frequency band assigned to the radio terminal unit in the cell center, and
- a second frequency band assigned to the radio terminal unit on the cell edge;
- (ii) further using properly the second frequency band by separating to:
- a beam form transmission of sending the same signal with an array weight multiplied to the plurality of radio terminal units from at least two or more antennas, and
- multiplex transmission of sending a different or independent signal from each of at least two or more antennas to the same radio terminal unit or the plurality of radio terminal units;
- wherein each radio base station apparatus specifies the information of frequency bands and transmission method in accordance with a state of each radio terminal unit;
- and
- wherein the radio base station apparatus or the radio terminal unit changes a report content of communication quality information from the radio terminal unit, depending on the specified frequency band and the specified transmission method.
A base station apparatus in a cellular radio communication system comprising the radio base station apparatus for making any one of a space multiplex transmission and a beam form transmission using a plurality of antennas and a plurality of radio terminal units,
- the radio base station apparatus,
- (i) separating communicable frequency band in the cellular radio communication system to:
- a first frequency band assigned to the radio terminal unit in the cell center, and
- a second frequency band, assigned to the radio terminal unit on the cell edge;
- (ii) further using properly the second frequency band by separating to:
- a beam form transmission of sending the same signal with an array weight multiplied to the plurality of radio terminal units from at least two or more antennas, and
- a space multiplex transmission of sending a different or independent signal from each of at least two or more antennas to the same radio terminal unit or the plurality of radio terminal units;
- and
- specifying the information of frequency band and transmission method in accordance with a state of each radio terminal unit;
- wherein the radio base station apparatus changes a report content of communication quality information from the radio terminal unit, depending on the specified frequency band and the specified transmission method.
A radio terminal unit in a cellular radio communication system comprising a radio base station apparatus for making any one of a space multiplex transmission and a beam form transmission using a plurality of antennas and the plurality of radio terminal units,
- by each radio base station apparatus,
- (i) separating communicable frequency band in the cellular radio communication system to:
- a first frequency band assigned to the radio terminal unit in the cell center, and
- a second frequency band, assigned to the radio terminal unit on the cell edge;
- (ii) further using properly the second frequency band by separating to:
- a beam form transmission of sending the same signal with an array weight multiplied to the plurality of radio terminal units from at least two or more antennas, and
- a space multiplex transmission of sending a different or independent signal from each of at least two or more antennas to the same radio terminal unit or the plurality of radio terminal units, and
- wherein the radio terminal unit receives a signal sent from the radio base station in any one of the first and second frequency bands, and in any one of the beam form transmission and the space multiplex transmission, by instruction from the radio base station determined in accordance with a state of each radio terminal unit,
- wherein the radio terminal unit changes a report content of communication quality information from the radio terminal unit, depending on the specified frequency band and the specified transmission method.
Dependencies are inferred from the claim text.