APPARATUS AND METHOD FOR SAVING POWER CONSUMPTION IN BROADBAND WIRELESS COMMUNICATION SYSTEM

• US 20110249715A1
• Filed: 04/13/2011
• Published: 10/13/2011
• Est. Priority Date: 04/13/2010
• Status: Active Grant

• Current Assignee: Samsung Electronics Co. Ltd.
• Original Assignee: Samsung Electronics Co. Ltd.
• Inventors: Ahn, Byung Chan, Maeng, Seung-Joo, Choi, Yun-Seok
• Granted Patent: US 8,891,649 B2
• Time in Patent Office: Days
• US Class Current: 375/222
• CPC Class Codes: H04B 7/0413 MIMO systems
• CPC Class Codes: H04B 7/0615 of weighted versions of same signal
• CPC Class Codes: H04W 28/0221 power availability or consumption
• CPC Class Codes: H04W 52/0274 by switching on or off the equipment or parts thereof
• CPC Class Codes: H04W 52/42 in systems with time, space, frequency or polarisation diversity
• CPC Class Codes: H04W 52/52 using AGC [Automatic Gain Control] circuits or amplifiers
• CPC Class Codes: H04W 72/0446 Resources in time domain, e.g. slots or frames
• CPC Class Codes: H04W 72/52 based on load
• CPC Class Codes: Y02D 30/70 in wireless communication networks

Abstract

An apparatus and method reduce power consumption in a broadband wireless communication system. A transmitting end apparatus that includes a plurality of transmit (Tx) antennas includes a control block, a Processor (DSP) block, a modem block, and at least one power controller. The control block determines a traffic amount based on an amount of used resources. The Digital Signal Processor (DSP) block performs scheduling by using a subset of Tx antennas and a subset of resources on a frequency axis if the traffic amount is less than a threshold. The modem block applies boosting to a signal transmitted using the subset of resources. And at least one controller turns off an operation of at least one power amplifier that corresponds to at least one Tx antenna that is not included in the subset of Tx antennas.

Claims

1. An apparatus of a transmitting end that includes a plurality of transmit (Tx) antennas in a wireless communication system, the apparatus comprising:

a control block configured to determine a traffic amount based on an amount of used resources;

a Digital Signal Processor (DSP) block configured to perform scheduling by using a subset of Tx antennas and a subset of resources on a frequency axis if the traffic amount is less than a threshold;

a modem block configured to apply boosting to a signal transmitted using the subset of resources; and

at least one power controller configured to off an operation of at least one power amplifier that corresponds to at least one Tx antenna that is not included in the subset of Tx antennas.

2. The apparatus of claim 1, wherein the control block is further configured to receive the amount of used resources provided from the DSP block in every frame.

3. The apparatus of claim 2, wherein the amount of used resources comprises a ratio of a number of actually allocated slots to a total number of slots that can be allocated.

4. The apparatus of claim 3, wherein the control block is further configured to determine a long-term averaged slot utilization rate by calculating an average amount of used resources and determine the traffic amount based on the long-term averaged slot utilization rate.

5. The apparatus of claim 4, wherein the control block is further configured to determine the long-term averaged slot utilization rate according to the following equation:

Su(n)=α

×

Su(n−

1)+(1−

α

)×

SUI(n),

where Su(n) denotes an n^th determined long-term averaged slot utilization rate, α

denotes a forgotten factor, and SUI(n) denotes an n^th provided Slot Utilization Information (SUI).

6. The apparatus of claim 1, wherein the control block is further configured to deliver to the DSP block a Mode Switch Indicator (MSI) that indicates whether the traffic amount is less than the threshold, and deliver to the at least one controller a Power Control Indicator (PCI) that indicates whether a power amplifier is turned off.

7. The apparatus of claim 1, wherein the subset of Tx antennas comprises half of all Tx antennas, and the subset of resources on the frequency axis comprise half of all subcarriers.

8. The apparatus of claim 7, wherein the boosting comprises 3 dB boosting.

9. The apparatus of claim 1, wherein the control block is further configured to select the subset of Tx antennas to be used to transmit signals based on SINRs for each Tx antenna fed back from a receiving end.

10. A method of operating a transmitting end that includes a plurality of transmit (Tx) antennas in a wireless communication system, the method comprising:

determining a traffic amount based on an amount of used resources;

performing scheduling by using a subset of Tx antennas and a subset of resources on a frequency axis if the traffic amount is less than a threshold;

applying boosting to a signal transmitted using the subset of resources; and

turning off an operation of at least one power amplifier that corresponds to at least one Tx antenna that is not included in the subset of Tx antennas.

11. The method of claim 10, wherein the amount of used resources comprises a ratio of a number of actually allocated slots to a total number of slots that can be allocated.

12. The method of claim 10, wherein determining the traffic amount comprises:

determining a long-term averaged slot utilization rate by calculating an average amount of used resources; and

determining the traffic amount based on the long-term averaged slot utilization rate.

13. The method of claim 12, wherein the long-term averaged slot utilization rate is determined by the following equation:

Su(n)=α

×

Su(n−

1)+(1−

α

)×

SUI(n),

where Su(n) denotes an n^th determined long-term averaged slot utilization rate, α

denotes a forgotten factor, and SUI(n) denotes an n^th provided Slot Utilization Information (SUI).

14. The method of claim 10, wherein the subset of Tx antennas comprises half of all Tx antennas, and the subset of resources on the frequency axis comprise half of all subcarriers.

15. The method of claim 14, wherein the boosting comprises 3 dB boosting.

16. The method of claim 10, further comprising:

selecting the subset of Tx antennas to be used to transmit signals based on SINRs for each Tx antenna fed back from a receiving end.

17. A method of operating a transmitting end that includes a plurality of transmit (Tx) antennas in a wireless communication system, the method comprising:

determining whether a traffic amount is less than a threshold;

when the traffic amount is less than the threshold, selecting a subset of Tx antennas and a subset of frequencies resources for transmitting signals;

turning off a power amplifier for at least one Tx antenna that is not included in the selected subset of Tx antennas; and

applying boosting to a signal transmitted through the selected subset of resources.

18. The method of claim 17, wherein determining whether a traffic amount is less than a threshold comprises:

determining a slot utilization rate for each frame; and

calculating a long-term averaged slot utilization rate based on a plurality of previously determined slot utilization rates.

19. The method of claim 18, wherein the slot utilization rate comprises a ratio of a number of actually allocated slots to a total number of slots that can be allocated.

20. The method of claim 17, wherein selecting the subset of Tx antennas comprises:

determining an estimated Signal to Interference-plus-Noise power Ratio (SINR) for each of the plurality of antennas; and

selecting at least one Tx antenna with the highest SINR.