Universal mobile telecommunications system (UMTS) terrestrial radio access (UTRA) frequency division duplex (FDD) downlink shared channel (DSCH) power control in soft handover

• US 6,650,905 B1
• Filed: 06/30/2000
• Issued: 11/18/2003
• Est. Priority Date: 06/30/2000
• Status: Expired due to Term

• Current Assignee: Conversant Wireless Licensing S.à.r.l. (f/k/a Core Wireless Licensing S.a.r.l.) (MOSAID Technologies Inc. (f/k/a Conversant Intellectual Property Management))
• Original Assignee: Nokia Mobile Phones UK Limited (Nokia Corporation)
• Inventors: Holma, Harri, Toskala, Antti
• Primary Examiner(s): Trost, William
• Assistant Examiner(s): Miller, Brandon J
• Application Number:
  US09/608,642
• Time in Patent Office: 1,236 Days
• Field of Search: 455/436, 455/442, 455/439, 455/522, 455/525
• US Class Current: 455/522
• CPC Class Codes: H04W 36/18 for allowing seamless reselection, e.g. soft reselection
• CPC Class Codes: H04W 36/304 due to measured or perceived resources with higher communication quality
• CPC Class Codes: H04W 52/40 during macro-diversity or soft handoff

Abstract

The indication given by SSDT in soft handover as to whether a cell is primary or not is used by base stations whether or not the base stations actually use it to configure DSCH transmission power with the principle that if the cell is primary, DSCH power is set based on DCH and, if not then a fixed power level or an offset with respect to DCH is used.

Claims

1. Method for use in a wireless telecommunications system (1) having at least one user equipment (UE) (10) and a plurality of base stations (20,22,24) connected to a common network controller (76), wherein said UE is able to periodically determine the magnitude of at least one parameter of plural radio downlinks (14,16,18) simultaneously established from more than one of said plurality of base stations to said UE in order to periodically decide which one of said more than one of said plural radio downlinks is from a currently preferred base station for use in a communications session between said UE and an end terminal in communication with said system, comprising the steps of:

periodically signaling on an uplink (60) from said UE to at least one of said more than one of said plurality of base stations that a dedicated downlink to said UE from said at least one of said more than one of said plurality of base stations is or is not from said currently preferred base station; and

periodically selecting, in response to said periodic signaling on said uplink from said UE, a power control method for at least a shared downlink to said UE from said at least one of said more than one of said plurality of base stations,

wherein, if said signaling step signals that said dedicated downlink from said at least one of said one or more base stations to said UE is from said currently preferred base station, then said step of periodically selecting selects a power control method for a shared downlink to said UE based on a power level of said dedicated downlink to said UE from said currently preferred base station, and

wherein the periodic signaling utilizes a site selection diversity transmission (SSDT) in the uplink.

2. The method of claim 1, wherein in response to said signaling step signaling that said dedicated downlink to said UE from said at least one of said one or more base stations is not from said currently preferred base station, said step of periodically selecting selects a fixed power level control method for a shared downlink to said UE from said not currently preferred base station.

7. The method of claim 2, wherein the dedicated downlink and the shared downlink are different from each other at least in that the UE is able to periodically determine the magnitude of the at least one parameter of the dedicated downlink.

8. The method of claim 1, wherein the dedicated downlink and the shared downlink are different from each other at least in that the UE is able to periodically determine the magnitude of the at least one parameter of the dedicated downlink.

11. The method of claim 2, wherein the dedicated downlink and the shared downlink are different from each other at least in that the dedicated downlink provides a pilot bit.

12. The method of claim 1, wherein the dedicated downlink and the shared downlink are different from each other at least in that the dedicated downlink provides a pilot bit.

15. The method of claim 1, wherein the site selection diversity transmission is also for controlling power of at least one dedicated physical channel in the downlink.

3. Apparatus for use in a wireless telecommunications system (1) having at least one user equipment (UE) (10) and a plurality of base stations (20, 22, 24) connected to a common network controller (76), wherein said UE is able to periodically determine the magnitude of at least one parameter of plural radio downlinks (14,16,18) simultaneously established from more than one of said plurality of base stations to said UE in order to periodically decide which one of said more than one of said plural radio downlinks is from a currently preferred base station for use in a communications session between said UE and an end terminal in communication with said system, comprising:

means for periodically signaling (56) on an uplink (60) from said UE to at least one of said more than one of said plurality of base stations that a dedicated downlink to said UE from said at least one of said more than one of said plurality of base stations is or is not from said currently preferred base station; and

means for periodically selecting (68), in response to said periodic signaling on said uplink from said UE, a power control method for at least a shared downlink to said UE from said at least one of said more than one of said plurality of base stations,

wherein said means for periodically selecting, if said signaling step signals that said dedicated downlink from said at least one of said one or more base stations to said UE is from said currently preferred base station, selects a power control method for a shared downlink based on a power level of said dedicated downlink to said UE from said currently preferred base station, and

wherein the periodic signaling utilizes a site selection diversity transmission (SSDT) in the uplink.

4. The apparatus of claim 3, wherein said means for periodically selecting, in response to said signaling step signaling that said dedicated downlink to said UE from said at least one of said one or more base stations is not from said currently preferred base station, selects a fixed power level control method for a shared downlink to said UE from said not currently preferred base station.

9. The method of claim 4, wherein the dedicated downlink and the shared downlink are different from each other at least in that the UE is able to periodically determine the magnitude of the at least one parameter of the dedicated downlink.

10. The method of claim 3, wherein the dedicated downlink and the shared downlink are different from each other at least in that the UE is able to periodically determine the magnitude of the at least one parameter of the dedicated downlink.

13. The method of claim 4, wherein the dedicated downlink and the shared downlink are different from each other at least in that the dedicated downlink provides a pilot bit.

14. The method of claim 3, wherein the dedicated downlink and the shared downlink are different from each other at least in that the dedicated downlink provides a pilot bit.

16. The apparatus of claim 3, wherein the site selection diversity transmission is also for controlling power of at least one dedicated physical channel in the downlink.

5. User equipment (UE) for use in a wireless telecommunications system having at least one said UE and a plurality of base stations connected to a common network controller, wherein said UE is able to periodically determine the magnitude of at least one parameter of plural radio downlinks simultaneously established from more than one of said plurality of base stations to said UE in order to periodically decide which one of said more than one of said plural radio downlinks is from a currently-preferred base station for use in a communications session between said UE and an end terminal in communication with said system, said UE comprising:

sensing means (12), responsive to a dedicated downlink signal (32) from a plurality of base stations for providing a corresponding plurality of sensed signals (42);

storage means (44), responsive to said plurality of sensed signals for storing said plurality of sensed signals and for providing said plurality of sensed signals (46) from storage upon demand;

comparator means (48), responsive to said plurality of sensed signals retrieved from said storage means for comparing a parameter relating to said sensed signals for providing an comparison signal (50) indicative of a comparison between the parameter magnitudes of said sensed signals;

selection means (52), responsive to said comparison signal from said comparator means for selecting a preferred base station and for providing a selection signal (54) indicative thereof; and

signaling means, responsive to said selection signal for providing an uplink signal (58) indicative of the preferred base station,

wherein the uplink signal uses a site selection diversity transmission (SSDT) to indicate the preferred base station.

6. Apparatus for use in a wireless telecommunications system having at least one user equipment (UE), wherein said system includes a plurality of base stations connected to a common network controller, wherein said UE is able to periodically determine the magnitude of at least one parameter of plural dedicated radio downlinks simultaneously established from more than one of said plurality of base stations to said UE in order to periodically decide which one of said more than one of said plural dedicated radio downlinks is from a currently-preferred base station for use in a communications session between said UE and an end terminal in communication with said system, wherein said apparatus is responsive to a selection signal from a user equipment indicating an identification of a preferred base station, said apparatus comprising:

selecting means (68), responsive to said uplink signal for determining whether the base station is preferred or not and providing a selection signal (70) indicative thereof; and

power control means (72), responsive to said selection signal, for providing a downlink control signal (74,14) to said user equipment with a power level selected according to whether or not a preferred base station is determined,

wherein the selection signal uses a site selection diversity transmission (SSDT) to identify the preferred base station.

17. Method for use in a wireless telecommunications system (1) having at least one user equipment (UE) and a plurality of base stations, comprising the steps of:

periodically signaling on an uplink from said UE to at least one of said more than one of said plurality of base stations that said at least one of said more than one of said plurality of base stations is or is not a currently preferred base station; and

periodically selecting, in response to said periodic signaling, a power control method for at least a shared downlink to said UE from said at least one of said more than one of said plurality of base stations,

wherein the periodic signaling utilizes a site selection diversity transmission (SSDT) in the uplink, and

wherein the step of selecting uses the SSDT to determine a power offset for the shared downlink.