Apparatus and method for adaptively changing uplink power control scheme according to mobile status in a TDD mobile communication system

• US 7,907,915 B2
• Filed: 06/25/2009
• Issued: 03/15/2011
• Est. Priority Date: 08/20/2004
• Status: Active Grant

• Current Assignee: Samsung Electronics Co. Ltd.
• Original Assignee: Samsung Electronics Co. Ltd.
• Inventors: Kwon, Young-Hoon, Sung, Sang-Hoon, Yang, Jang-Hoon, Hwang, In-Seok, Yoon, Soon-Young, Cho, Jae-Hee, Huh, Hoon
• Primary Examiner(s): Pan; Yuwen
• Assistant Examiner(s): Nguyen; Hai V
• Application Number:
  US12/491,774
• Publication Number:
  US 20090262670A1
• Time in Patent Office: 628 Days
• Field of Search: 455/69, 370/280
• US Class Current: 455/69
• CPC Class Codes: H04W 52/08 Closed loop power control
• CPC Class Codes: H04W 52/10 Open loop power control
• CPC Class Codes: H04W 52/28 using user profile, e.g. mobile speed, priority or network state, e.g. standby, idle or non transmission

Abstract

An apparatus and method for changing an uplink power control scheme according to mobile status in a TDD mobile communication system are provided. The communication system comprises a Subscriber Station (SS) for transmitting a power control change request message to a Base Station (BS) to change the power control scheme, and the BS for deciding to change the power control scheme between the open loop power control and closed loop power control, and transmitting a power control change response message the SS including the decided power control scheme.

Claims

1. A broadband wireless communication system supporting an open loop power control and a closed loop power control, the system comprising:

a Subscriber Station (SS) for transmitting a power control change request message to a Base Station (BS) to change a power control scheme; and

the BS for deciding to change the power control scheme between the open loop power control and the closed loop power control, and for transmitting, to the SS, a power control change response message including a decided power control scheme,

wherein the power control change response message includes a power control mode change field indicating the decided power control scheme, a start frame field indicating a frame number at which the indicated power control scheme is activated, a power adjust field indicating a change in power level that the SS should apply to its current transmission power, if the indicated power control scheme is the closed-loop power control, and an offset field indicating a change in power level that the SS should apply to an open loop power control formula, if the indicated power control scheme is the open-loop power control.

2. An apparatus for a Base Station (BS) in a wireless communication system supporting at least two uplink power control schemes, the apparatus comprising:

a modem for receiving from a Subscriber Station (SS), a power control change request message and

for transmitting a power control change response message to the SS,

wherein the power control change request message includes a first power control mode change field indicating a first power control scheme requested by the SS, and an UpLink (UL) Transmission (Tx) power field indicating a transmit power of an uplink burst that carries the power control change request message, and

wherein the power control change response message includes a second power control mode change field indicating a second power control scheme decided by the BS, a start frame field indicating a frame number at which the second power control scheme is activated, a power adjust field indicating a change in power level that the SS should apply to its current transmission power, if the second power control scheme is a closed-loop power control, and an offset field indicating a change in power level that the SS should apply to an open loop power control formula, if the second power control scheme is an open-loop power control.

3. The apparatus of claim 2, further comprising:

a controller for deciding the second power control scheme for an uplink of the SS, and for comparing the second power control scheme with a previous power control scheme,

wherein the modem transmits the power control change response message to the SS, if the second power control scheme is different from the previous power control scheme.

4. An apparatus for determining an uplink power control scheme in a Subscriber Station (SS) for a wireless communication system supporting at least two uplink power control schemes, the apparatus comprising:

a modem for transmitting, to a Base Station (BS), a power control change request message and for receiving, from the BS, a power control change response message,

wherein the power control change request message includes a first power control mode change field indicating a first power control scheme requested by the SS, and an Uplink (UL) Transmission (Tx) power field indicating a transmit power of an uplink burst that carriers the power control change request message, and

wherein the power control change request message includes a second power control mode change field indicating a second power control scheme decided by the BS, a start frame field indicating a frame number at which the second power control scheme is activated, a power adjust field indicating a change in power level that the SS should apply to its current transmission power, if the second power control scheme is a closed-loop power control, and an offset field indicating a change in power level that the SS should apply to an open loop power control formula, if the second power control scheme is an open-loop power control.

5. The apparatus of claim 4, further comprising:

a controller for determining whether to change a power control scheme based on a velocity of the SS.

6. The apparatus of claim 4, further comprising:

a controller for deciding the first power control scheme according a status of the SS, and for comparing the decided first power control scheme with a previous power control scheme,

wherein the modem transmits the power control change request message to the BS, if the decided first power control scheme is different from the previous power control scheme.

7. The apparatus of claim 4, wherein the modem transmits a bandwidth request message to the BS, if the SS requests a bandwidth from the BS,

wherein the bandwidth request message includes a Bandwidth Request (BR) field indicating an amount of uplink data to be transmitted and an UL Tx power field indicating a transmit power of an uplink burst that carries the bandwidth request message.

8. An apparatus for a Base Station (BS) in a wireless communication system supporting at least two uplink power control schemes, the apparatus comprising:

a controller for deciding a power control scheme for an uplink of a Subscriber Station (SS); and

a modem for transmitting a power control change response message including information about a decided power control scheme to the SS,

wherein the power control change response message includes a power control mode change field indicating the decided power control scheme, a start frame field indicating a frame number at which the indicated power control scheme is activated, a power adjust field indicating a change in power level that the SS should apply to its current transmission power, if the indicated power control scheme is a closed-loop power control, and an offset field indicating a change in power level that the SS should apply to an open loop power control formula, if the indicated power control scheme is an open-loop power control.

9. The apparatus of claim 8, wherein the controller decides the power control scheme, upon request from the SS.

10. The apparatus of the claim 8, wherein the controller compares the decided power control scheme with a previous power control scheme, and

wherein the modem transmits the power control response message to the SS, if the decided power control scheme is different from the previous power control scheme.

11. An apparatus for a Subscriber Station (SS) in a wireless communication system supporting at least two power control schemes, the apparatus comprising:

a modem for receiving a power control change response message from a Base Station (BS);

and

a controller for determining a transmit power of an uplink signal according to the power control response message;

wherein the power control change response message includes a power control mode change field indicating a power control scheme decided by the BS, a start frame field indicating a frame number at which the indicated power control scheme is activated, a power adjust field indicating a change in power level that the SS should apply to its current transmission power, if the indicated power control scheme is a closed-loop power control, and an offset field indicating a change in power level that the SS should apply to an open loop power control formula, if the indicated power control scheme is an open-loop power control.

12. The apparatus of claim 11, wherein the

modem transmits a bandwidth request message to the BS, if the SS requests bandwidth from the BS,

wherein the bandwidth request message includes a Bandwidth Request (BR) field indicating an amount of uplink data to be transmitted and an UpLink (UL) Transmission (Tx) power field indicating a transmit power of an uplink burst that carries the bandwidth request message.