ADAPTIVE TRANSMISSION SELECTION

• US 20110256893A1
• Filed: 12/19/2008
• Published: 10/20/2011
• Est. Priority Date: 12/19/2008
• Status: Active Grant

• Current Assignee: Telefonaktiebolaget LM Ericsson
• Original Assignee: Telefonaktiebolaget LM Ericsson
• Inventors: Johannisson, Bjorn Gunnar, Athley, Fredrik
• Granted Patent: US 8,588,854 B2
• Time in Patent Office: Days
• US Class Current: 455/500
• CPC Class Codes: H04B 7/0693 switching off a diversity branch, e.g. to save power
• CPC Class Codes: H04W 52/42 in systems with time, space, frequency or polarisation diversity
• CPC Class Codes: H04W 72/52 based on load

Abstract

A controlling station (110, 400) comprising an antenna arrangement (420) with a number of antennas, which each covers one of a number of adjacent cells, with a main beam with a beamwidth that extends into two immediately adjacent cells. The controlling station (110, 400) is adapted to:—transmit on a control channel on a first number of antennas,—measure the output power on the traffic channels on the first number of antennas,—if the traffic channel output power on any of said first number of antenna is above a threshold, transmission on the control channel is activated on a second number of antennas,—measure the traffic channel output power on each antenna in the antenna arrangement,—if the measured traffic channel output power on an antenna is below a second threshold and the traffic channel on the antennas of both adjacent cells is active, the control channel transmissions on that antenna are deactivated.

Claims

1. A controlling station for one or more cells in a cellular telecommunications system, comprising a transmitter and an antenna arrangement with a first number of antennas, each of which is adapted to cover one of a number of adjacent cells, in which each antenna has a beamwidth such that the main beam extends by a certain amount into two cells which are immediately adjacent on each side of the cell which the antenna is adapted to cover, the controlling station configured to:

transmit on a control channel on a first number of antennas which cover non-adjacent cells;

measure the output power which is transmitted on the traffic channels on each of said first number of antennas;

if the measured total traffic channel output power on any of said first number of antenna is above a first predefined threshold, transmission on the control channel is activated on a second number of antennas;

measure the traffic channel output power on each of the antennas in the antenna arrangement; and

if the measured traffic channel output power on an antenna is below a second predefined threshold and the traffic channel on the antennas of both adjacent cells is active, the control channel transmissions on that antenna are deactivated.

2. The controlling station of claim 1, wherein the half-power beamwidth (α

) of the main beam of each antenna is in the range of 40-70 degrees.

3. The controlling station of claim 1, wherein the half-power beamwidth (α

) of the main beam of each antenna is in the range of 45-55 degrees.

4. The controlling station of claim 1, wherein the half-power beamwidth (α

) of the main beam of each antenna is 50 degrees.

5. The controlling station of claim 1, wherein the total coverage afforded by the antennas in the antenna arrangement is 360 degrees.

6. The controlling station of claim 5, wherein the antenna covers a cell of 60 degrees width.

7. The controlling station of claim 1, wherein the first number of antennas is half the total number of antennas in the antenna arrangement.

8. The controlling station of claim 1, wherein the second number of antennas is half the total number of antennas in the antenna arrangement.

9. The controlling station of claim 1, wherein the second predefined threshold is larger than the first predefined threshold.

10. The controlling station (110, 400) of claim 1, wherein, when the control channel transmissions on an antenna are deactivated, the deactivation is done gradually, according to a predefined curve.

11. A method for use in a controlling station of one or more cells in a cellular telecommunications system, the method comprising equipping the controlling station with an antenna arrangement with a first number of antennas, each of which is adapted to cover one of a number of adjacent cells, with each antenna having a a beamwidth such that the main beam extends by a certain amount into two cells which are immediately adjacent on each side of the cell which the antenna is adapted to cover;

transmitting on a control channel on a first number of antennas which cover non-adjacent cells;

measuring the output power which is transmitted on the traffic channels on each of said first number of antennas;

checking if the measured total traffic channel output power on any of said first number of antenna is above a first predefined threshold (T1), and if that is the case, activating transmission on the control channel on a second number of antennas;

measuring the traffic channel output power on each of the antennas in the antenna arrangement; and

deactivating the control channel transmissions on an antenna of a cell if the measured traffic channel output power on that antenna is below a second predefined threshold and the traffic channel on the antennas of both adjacent cells is active.

12. The method of claim 11, wherein the half-power beamwidth (α

) of the main beam of the antennas of the antenna arrangement with which the controlling station is equipped is in the range of 40-70 degrees.

13. The method of claim 11, wherein the half-power beamwidth (α

) of the main beam of the antennas of the antenna arrangement with which the controlling station is equipped is in the range of 45-55 degrees.

14. The method of claim 11, wherein the half-power beamwidth (α

) of the main beam of the antennas of the antenna arrangement with which the controlling station is equipped is 50 degrees.

15. The method of claim 11, wherein the antennas of the antenna arrangement have a total coverage of 360 degrees.

16. The method of claim 15, wherein each antenna is arranged to cover a cell of 60 degrees width.

17. The method of claim 11, wherein the first number of antennas is half the total number of antennas in the antenna arrangement.

18. The method of claim 11, wherein the second number of antennas is half the total number of antennas in the antenna arrangement.

19. The method of claim 11, wherein the second predefined threshold is larger than the first predefined threshold.

20. The method of claim 11, wherein, when the control channel transmissions on an antenna are deactivated, the deactivation is done gradually, according to a predefined curve.