Method and apparatus for controlling signal quality in a CDMA cellular telecommunications

• US 5,623,484 A
• Filed: 12/15/1994
• Issued: 04/22/1997
• Est. Priority Date: 09/24/1993
• Status: Expired due to Term

• Current Assignee: Tyco Electronics Logistics
• Original Assignee: Nokia Telecommunications Oy (Nokia Corporation)
• Inventors: Muszynski, Peter
• Primary Examiner(s): Olms, Douglas W.
• Assistant Examiner(s): TON, DANG T
• Application Number:
  US08/307,689
• Time in Patent Office: 859 Days
• Field of Search: 370/17, 370/13, 370/13.1, 370/95.1, 370/95.2, 370/95.3, 370/85.7, 370/18, 370/85.3, 375/205, 375/200, 375/208, 375/278, 375/296, 379/59, 379/60, 379/61, 379/94, 379/95, 379/96, 379/58, 379/63, 455/33.1, 455/34.1, 455/59, 455/60, 455/38.3, 455/33.2, 455/33.3, 455/33.4, 455/54.2, 455/56.1, 371/37.9, 371/38.1, 371/39.1, 371/64
• US Class Current: 370/335
• CPC Class Codes: H04W 36/18 for allowing seamless reselection, e.g. soft reselection
• CPC Class Codes: H04W 52/08 Closed loop power control
• CPC Class Codes: H04W 52/12 Outer and inner loops
• CPC Class Codes: H04W 52/18 TPC being performed according to specific parameters
• CPC Class Codes: H04W 52/386 centralized, e.g. when the radio network controller or equivalent takes part in the power control

Abstract

A system and a method for controlling the radio signal quality between a plurality of mobile stations and a plurality of base stations connected to a mobile switching center of a code division multiple access (CDMA) cellular telecommunication system. Each base station is adapted to measure the quality of each active CDMA communication link and to report for each active CDMA radio communication to the mobile switching center the corresponding measured communication signal quality. The mobile switching center is adapted to perform an averaging process on the reported quality measure values, in order to calculate a recommended quality measure threshold value. The base stations are adapted to receive the recommended threshold value for use in an uplink closed-loop power control algorithm for the mobile stations.

Claims

1. A system for controlling the quality of radio signals on active code division multiple access (CDMA) communication links between a plurality of mobile stations and a plurality of base stations connected to a mobile switching center of a CDMA cellular telecommunications system, wherein:

each of said base stations is adapted to measure the quality of each said active CDMA communication link and to report, for each active CDMA radio communication over each said link, to said mobile switching center, each corresponding measured value of communication signal quality;

said mobile switching center is adapted to perform an averaging of said measured values of communication signal quality, for calculating a recommended quality measure threshold value;

said base stations are adapted to receive said recommended quality measure threshold value from said mobile switching center; and

said base stations are arranged to control power of their respective transmissions by said mobile stations, by an uplink closed-loop power control algorithm, for maintaining the quality of radio signals on each said active CDMA communication link maximally close to said recommended threshold value.

2. A system according to claim 1, wherein:

said mobile switching center is adapted to perform an averaging operation on said measured values of quality reported thereto, over some or all of the active CDMA communications links controlled by said mobile switching center.

3. A system according to claim 1, wherein:

each said measured value of quality is a signal-to-interference-plus noise ratio.

4. A system according to claim 2, wherein:

each said measured value of quality is a signal-to-interference-plus noise ratio.

5. A system according to claim 1, wherein:

each said measured value of quality is a bit error rate.

6. A system according to claim 2, wherein:

each said measured value of quality is a bit error rate.

7. A method for controlling the quality of radio signals on active code division multiple access (CDMA) communication links between a plurality of mobile stations and a plurality of base stations connected to a mobile switching center of a CDMA cellular telecommunications system, wherein:

each of said base stations measuring the quality of each said active CDMA communication link and reporting, for each active CDMA radio communication over each said link, to said mobile switching center, each corresponding measured value of communication signal quality;

said mobile switching center performing an averaging of said measured values of communication signal quality, and calculating a recommended quality measure threshold value;

said base stations receiving said recommended quality measure threshold value from said mobile switching center; and

said base stations controlling power of their respective transmissions by said mobile stations, by an uplink closed-loop power control algorithm, for maintaining the quality of radio signals on each said active CDMA communication link maximally close to said recommended threshold value.

8. A method according to claim 7, wherein:

said mobile switching center performs an averaging operation on said measured values of quality reported thereto, over some or all of the active CDMA communications links controlled by said mobile switching center.

9. A method according to claim 7, wherein:

each said measured value of quality is a signal-to-interference-plus noise ratio.

10. A method according to claim 8, wherein:

each said measured value of quality is a signal-to-interference-plus noise ratio.

11. A method according to claim 7, wherein:

each said measured value of quality is a bit error rate.

12. A method according to claim 8, wherein:

each said measured value of quality is a bit error rate.