APPARATUS AND METHOD FOR ADAPTIVELY CHANGING UPLINK POWER CONTROL SCHEME ACCORDING TO MOBILE STATUS IN A TDD MOBILE COMMUNICATION SYSTEM

• US 20090262670A1
• Filed: 06/25/2009
• Published: 10/22/2009
• 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, Huh, Hoon, CHO, Jae-Hee
• Granted Patent: US 7,907,915 B2
• Time in Patent Office: Days
• US Class Current: 370/280
• 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 the 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 transmitting a power control change response message to the SS 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 as to when 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_perSS 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 reception modem for receiving from a Subscriber Station (SS), a power control change request message including information about a requested power control scheme; and

a transmission modem for transmitting a power control change command message to the SS,

wherein the power control change request message includes a power control mode change field indicating a 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 command message includes a power control mode change field indicating a 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_perSS 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.

3. The apparatus of claim 2, further comprising:

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

wherein the transmission modem transmits the power control change command to the SS, if the decided 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 transmission modem for transmitting, to a Base Station (BS), a power control change request message including information about a requested power control scheme; and

a reception modem for receiving a power control change command message from the BS,

wherein the power control change request message includes a power control mode change field indicating the requested power control scheme 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 command message includes a power control mode change field indicating a 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_perSS 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.

5. The apparatus of claim 4, further comprising:

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

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

7. The apparatus of claim 4, wherein the transmission 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:

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

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

wherein the power control change command 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_perSS 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 uplink power controller decides the power control scheme, upon request from the SS.

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

wherein the transmission modem transmits the power control command 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 reception modem for receiving a power control change command message from a Base Station (BS);

a Media Access Control (MAC) block for extracting information about a decided power control scheme from the power control change command message; and

a power controller for selecting a power control scheme according to the extracted information, and determining a transmit power of an uplink signal according to the selected power control scheme;

wherein the power control change command 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_perSS 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, further comprising:

a transmission modem for transmitting 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.