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US 6,633,556 B1Granted
Mobile communications system and mobile communications method
AssigneeMatsushita Electric Industrial Co., Ltd.
InventorTakaaki Sato
Life of this patent
Estimating the term…
Abstract
Even in a case where a using frequency differs for each region of a service area, a mobile direction of a mobile station M is determined by a mobile direction determination section 115 in a network side (control station), and whether or not the mobile station M moves out of the same frequency area is determined by a determination section 116 for an outer area of the same frequency, and the using frequency is changed in advance by a frequency change section 104 of the mobile station
Claims8
A mobile station apparatus of a CDMA system comprising:
- a radio communication system that is capable of communicating using at least a first frequency and a second frequency;
- a received quality measuring system that measures received qualities of signals of the first frequency and the second frequency transmitted from adjacent cells using respective spreading codes assigned to the cells to perform cell searching;
- and
- a frequency change system that determines a second base station apparatus as a destination of handover based on the received qualities, and change frequency according to a frequency changes instruction signal that instructs a change from the first frequency to the second frequency, when a movement direction of said mobile station apparatus is from a cell of a first base station apparatus that uses the first frequency and the second frequency and is communicating with said mobile station apparatus using the first frequency, to a cell of said second base station apparatus which communicates using the second frequency,
- wherein the movement direction is determined from a result obtained by measuring the received qualities of signals transmitted from the adjacent cells using the respective spreading codes assigned to the cells, and said mobile station apparatus performs a soft handover from the cell of said first base station apparatus to the cell of said second base station apparatus determined based on the received qualities in said received quality measuring system, after changing the frequency.
2 more elements
A control station apparatus of a CDMA system comprising:
- a movement direction determination system that acquires, through a base station apparatus, a result of a periphery cell search obtained in a mobile station apparatus, by measuring received qualities of a plurality of signals transmitted from adjacent cells using at least one of a first frequency used by said base station apparatus to communicate with said mobile station apparatus, and a second frequency used by another base station apparatus as a candidate for destination of handover of said mobile station apparatus, each of said base station apparatus and said another base station apparatus using a respective one of spreading codes assigned to the cells, and that determines a movement direction of said mobile station apparatus based on the result of the periphery cell search;
- a frequency change instructing system that transmits a frequency change instruction signal for instructing said mobile station apparatus to change from the first frequency to the second frequency, when the movement direction of said mobile station apparatus is from a cell of a first base station with which said mobile station apparatus is communicating using the first frequency to a cell of a second base station apparatus which communicates using the second frequency;
- and
- a handover control system that performs a soft handover of said mobile station apparatus from the cell of said first base station apparatus to the cell of said second base station apparatus determined based on the received qualities of the signals transmitted from the cells measured in said mobile station apparatus, after changing the frequency of said mobile station apparatus.
1 more element
A radio communication method of a CDMA system comprising:
- measuring, in a mobile station apparatus, received qualities of signals of a first frequency used by the mobile station in communicating and a second frequency used by a base station apparatus as a candidate for destination of handover of the mobile station apparatus, transmitted from adjacent cells using respective spreading codes assigned to the cells;
- determining whether a movement direction of the mobile station apparatus is from a cell of a first base station apparatus which uses the first frequency and the second frequency and is communicating with the mobile station apparatus using the first frequency to a cell of a second base station apparatus which communicates using the second frequency;
- changing a communication frequency of the mobile station apparatus from the first frequency to the second frequency when a movement is detected in the movement direction from the cell of the first base station apparatus to the cell of the second base station apparatus determined based on a measurement result of the received qualities;
- and
- performing a soft handover of the mobile station apparatus from the cell of the first base station apparatus where the mobile station apparatus has changed the frequency to the cell of the second base station apparatus.
2 more elements
Dependencies are inferred from the claim text.