Method of and apparatus for acquiring strength information from received signals transmitted by a plurality of base stations and for transmitting a signal thereof

• US 5,978,657 A
• Filed: 01/17/1996
• Issued: 11/02/1999
• Est. Priority Date: 01/19/1995
• Status: Expired due to Term

• Current Assignee: Sony Corporation (Sony Group Corp.)
• Original Assignee: Sony Corporation (Sony Group Corp.)
• Inventors: Suzuki, Mitsuhiro
• Primary Examiner(s): Eisenzopf, Reinhard J.
• Assistant Examiner(s): LE, THANH C
• Application Number:
  US08/586,374
• Time in Patent Office: 1,385 Days
• Field of Search: 455/33.1, 455/34.1, 455/54.1, 455/54.2, 455/56.1, 455/62, 455/63, 455/67.1, 455/67.3, 455/67.6, 455/69, 455/70, 455/89, 379/59
• US Class Current: 455/522
• CPC Class Codes: H04W 52/24 using SIR [Signal to Interference Ratio] or other wireless path parameters
• CPC Class Codes: H04W 52/343 taking into account loading or congestion level
• CPC Class Codes: H04W 52/346 distributing total power among users or channels

Abstract

Power measuring reference signals from a plurality of base stations are transmitted with a predetermined electric power. These reference signals transmitted from the base stations are received by a mobile station. The propagation loss of each base station is detected in response to a reception power of the received reference signal. When the mobile station issues a communication request, the mobile station connects to a communication network between it and a base station with the detected smallest propagation loss. Then, a ratio between the reception power of the reference signal transmitted from the base station connected with the communication network and reception powers of the reference signals transmitted from all other base stations using the same frequency band as that of the base station connected with the communication network is detected and the value of the detected ratio is transmitted to the base station. Then, the base station controls the transmission power of the communication network based on the value of this ratio.

Claims

1. A method of communication between one of a plurality of base stations and a mobile station, for a cellular system having said plurality of base stations located in a predetermined arrangement, comprising the steps of:

transmitting power measuring reference signals from said plurality of base stations by a normal power strength;

receiving said power measuring reference signals from said base stations by said mobile station;

detecting a propagation loss of each of said plurality of base stations in response to a received power strength of said received power measuring reference signal;

connecting said mobile station to a base station with minimum detected propagation loss by a communication channel when said mobile station issues a communication request signal;

detecting a ratio between said received power strength of said power measuring reference signal transmitted from said base station connected to said mobile station by said communication channel and a sum of received power strength of said power measuring reference signals transmitted from all receivable one of said plurality of base stations using the same frequency band as that used for said communication channel;

transmitting a value of the detected ratio to said base station connected to said mobile station by said communication channel; and

controlling a transmission power strength of said communication channel on the basis of the value of said ratio by said base station which received the value of said ratio.

2. The method according to claim 1, wherein said transmission power strength is set to a value proportional to -β

square of the value of said ratio transmitted for said mobile station where β

is a constant ranging from 1≧

β

>

0.

3. The method according to claim 2, wherein said constant β

is about 0.5.

4. The method according to claim 1, wherein said transmission power strength has a lower limit value and said lower limit value is used as said transmission power strength when said transmission power strength is lower than said lower limit value.

5. A method of communication between a mobile station and any of a plurality of base stations in a cellular system, comprising the steps of:

receiving a plurality of power measuring reference transmitted from said plurality of base stations by use of a same frequency band;

obtaining a plurality of reception level information of said plurality of received power measuring reference signals;

obtaining a maximum reception level information from each of said plurality of obtained reception level information and a cumulative reception level information generated from accumulated reception level information other than said maximum reception level information;

transmitting a signal based on said maximum reception level information and said cumulative reception level information to a base station having said maximum reception level; and

opening a communication network between said mobile station and said base station having said maximum reception level when said mobile station and a base station have a communication request, wherein said mobile station can reduce interference of received signals and receive a signal from said base station each time said base station controls a transmission power of signal based on said maximum reception level information and said cumulative reception level information to said mobile station.

6. The method according to claim 5, further comprising a step of calculating a ratio between said maximum reception level information and said cumulative reception level information.

7. A mobile station in a cellular system in which said mobile station communicates with any one of a plurality of base stations, said mobile station in said cellular system comprising:

reception means for receiving a plurality of power measuring reference signals transmitted from said plurality of base stations using a same frequency band;

memory means for obtaining and storing a plurality of reception level information of said plurality of respective power measuring reference signals received at said reception means;

means for obtaining a maximum reception level information and a cumulative reception level information generated from a portion of said reception level information stored in said memory means;

means for generating a signal based on said maximum reception level information and said cumulative reception level information;

means for transmitting said signal generated by said generating means to a base station having said maximum reception level; and

means for opening a communication channel between said mobile station and said base station having said maximum reception level for making a call when said mobile station and a base station have a communication request, wherein said mobile station reduces interference of a plurality of received signals and receives a signal from said base station each time said base station controls a transmission power of said signal to said mobile station based on said maximum reception level information and said cumulative reception level.

8. The method according to claim 7, further comprising means for calculating a ration between said maximum reception level information and said cumulative reception level information from signals based on said maximum reception level information and said cumulative reception level information and wherein ratio information is transmitted to a base station.