Method for controlling transmission power

• US 20040152481A1
• Filed: 11/24/2003
• Published: 08/05/2004
• Est. Priority Date: 06/01/2001
• Status: Active Grant

• Current Assignee: WSOU Investments, LLC (WSOU Holdings, LLC)
• Original Assignee: Alcatel-Lucent SA (Nokia Corporation)
• Inventors: Georgeaux, Eric, Fauconnier, Denis
• Granted Patent: US 7,228,147 B2
• Time in Patent Office: Days
• US Class Current: 455/522
• CPC Class Codes: H04W 16/14 Spectrum sharing arrangements between different networks
• CPC Class Codes: H04W 52/36 with a discrete range or set of values, e.g. step size, ramping or offsets
• CPC Class Codes: H04W 52/50 at the moment of starting communication in a multiple access environment
• CPC Class Codes: H04W 52/52 using AGC [Automatic Gain Control] circuits or amplifiers
• CPC Class Codes: H04W 74/08 Non-scheduled access, e.g. ALOHA hybrid access H04W74/02

Abstract

In certain circumstances, a mobile radiocommunication terminal (2, 3) estimates an initial radio signal transmission power, i.e. a random access request, to a base station (1) located within the range thereof. If it is very close to said station, said initial estimated power can be lower, even greatly lower, than the minimum transmission power of the mobile terminal. In order to limit interference with other communications in progress, the transmission of said signals is inhibited if the difference between the minimum transmission power and the initial estimated power lies beyond a predefined threshold.

Claims

1. Method of controlling the transmission power of a mobile radio terminal (2, 3) on a communication resource of a base station (1), the mobile terminal having a minimum radio signal transmission power, wherein, before transmitting radio signals for entering into communication with the base station, the mobile terminal estimates an initial transmission power for the radio signals on said resource, compares the difference between its minimum transmission power and the estimated initial power with a predefined threshold, and inhibits transmission of radio signals on said resource if the difference lies beyond said threshold.

2. Method according to claim 1, wherein the base station (1) broadcasts a marker signal at a determined transmission power, and wherein the mobile terminal (2, 3) measures a reception power of said marker signal and estimates the initial transmission power on said resource according to the measured reception power.

3. Method according to claim 1 or 2, wherein the mobile terminal (2, 3) transmits said radio signals at its minimum power if the difference is below said threshold.

4. Method according to any one of the above claims, wherein the predefined threshold is selected according to a type of communication resource of the base station (1).

5. Method according to claim 4, wherein the predefined threshold is a threshold fixed for each type of communication resource of the base station (1) and previously registered in the mobile terminal (2, 3).

6. Method according to any one of the above claims, wherein the value of said threshold is included in system information broadcast by the base station (1) and received by the mobile terminal (2, 3) before entering into communication with the base station.

7. Method according to claim 6, wherein the value of said threshold varies over time.

8. Method according to claim 6 or 7, wherein the value of said threshold varies in an adaptive manner according to a traffic load observed on the base station (1).

9. Method according to any one of the above claims, wherein said radio signals carry a random access request.

10. Mobile terminal, comprising means (23, 24) for transmitting radio signals with a transmission power at least equal to a set minimum power, means (20, 21) for estimating an initial transmission power of radio signals on a communication resource to enter into communication with a base station (1), means (24) for comparing the difference between said minimum power and the initial estimated power with a predefined threshold, and means (24) for inhibiting the transmission of radio signals on said resource if the difference lies beyond said threshold.

11. Mobile terminal according to claim 10, wherein the means for estimating the initial power comprise means (21) for measuring a reception power of a marker signal transmitted at a power determined by the base station (1).

12. Mobile terminal according to claim 10 or 11, comprising means (20, 21) for extracting the value of said threshold from system information broadcast by the base station (1) and received before entering into communication with the base station.

13. Radio communication base station, comprising means (11-17) for transmitting and receiving radio signals, characterized in that the transmission means comprise means (12) for broadcasting system information including the value of a power threshold, such as to prevent mobile terminals (2, 3) situated within range of the base station (1) from sending radio signals on a communication resource, before establishing a radio link with said base station, with a transmission power greater than an initial power estimated by the mobile terminal, increased by the value of the said threshold.

14. Base station according to claim 13, wherein the means for transmission include means (11) for broadcasting a marker signal at a transmission power indicated in the system information.

15. Base station according to claim 13 or 14, wherein the value of said threshold varies over time.

16. Base station according to any of claims 13 to 15, wherein the value of said threshold varies in adaptive manner according to an observed traffic load.