Apparatus and method for feeding back channel quality information and scheduling apparatus and method using the same in a wireless communication system

• US 20070098093A1
• Filed: 08/29/2006
• Published: 05/03/2007
• Est. Priority Date: 08/29/2005
• Status: Active Grant

• Current Assignee: Samsung Electronics Co. Ltd.
• Original Assignee: Samsung Electronics Co. Ltd.
• Inventors: Jeong, Kyeong-In, Han, Jin-Kyu, Kim, Dong-Hee, Kwon, Hwan-Joon
• Granted Patent: US 8,094,733 B2
• Time in Patent Office: Days
• US Class Current: 375/260
• CPC Class Codes: H04B 17/24 with feedback of measurements to the transmitter
• CPC Class Codes: H04B 17/26 using historical data, averaging values or statistics
• CPC Class Codes: H04B 17/30 of propagation channels
• CPC Class Codes: H04B 17/309 Measuring or estimating channel quality parameters
• CPC Class Codes: H04B 17/327 Received signal code power [RSCP]
• CPC Class Codes: H04B 7/0689 using different transmission schemes, at least one of them being a diversity transmission scheme
• CPC Class Codes: H04L 1/0003 by switching between different modulation schemes
• CPC Class Codes: H04L 1/0026 Transmission of channel quality indication
• CPC Class Codes: H04L 27/2601 Multicarrier modulation systems
• CPC Class Codes: H04L 5/0007 the frequencies being orthogonal, e.g. OFDM(A), DMT
• CPC Class Codes: H04L 5/0053 Allocation of signaling, i.e. of overhead other than pilot signals
• CPC Class Codes: H04L 5/0057 Physical resource allocation for CQI
• CPC Class Codes: H04W 24/08 Testing, supervising or monitoring using real traffic
• CPC Class Codes: H04W 24/10 Scheduling measurement reports ; Arrangements for measurement reports
• CPC Class Codes: H04W 52/225 Calculation of statistics, e.g. average, variance
• CPC Class Codes: H04W 52/247 where the output power of a terminal is based on a path parameter sent by another terminal
• CPC Class Codes: H04W 52/325 Power control of control or pilot channels
• CPC Class Codes: H04W 72/0453 Resources in frequency domain, e.g. a carrier in FDMA
• CPC Class Codes: H04W 72/21 in the uplink direction of a wireless link, i.e. towards the network
• CPC Class Codes: H04W 72/542 using measured or perceived quality

Abstract

An apparatus and method are provided for feeding back channel quality information and performing scheduling using the fed-back channel quality information in a wireless communication system based on Orthogonal Frequency Division Multiple Access (OFDMA). In the OFDMA wireless communication system, forward performance degradation due to a decrease in an amount of reverse channel quality information is reduced, and also an increase in the reverse load due to channel quality information feedback is suppressed. A base station controls power of a physical channel using information fed back from a mobile station. In a method for feeding back channel quality information from the mobile station, sub-band-by-sub-band channel quality information is measured and channel-by-channel quality information of a number of channels is transmitted in order of sub-bands of better channel quality information. Average channel quality information for a total band is measured and transmitted.

Claims

1. A method for feeding back channel quality information from a mobile station in a wireless communication system based on Orthogonal Frequency Division Multiple Access (OFDMA), the method comprising:

measuring sub-band-by-sub-band channel quality information;

transmitting, in at least one of a plurality of slots, channel-by-channel quality information of a number of channels in order of sub-bands with better channel quality information;

measuring average channel quality information for a total band in the OFDMA wireless communication system; and

transmitting, in at least one of the plurality of slots, the average channel quality information.

2. The method of claim 1, wherein the channel-by-channel quality information and the average channel quality information are transmitted in every slot.

3. The method of claim 2, wherein the measuring the average channel quality information comprises computing the average channel quality information by excluding a transmitted sub-band channel quality value.

4. The method of claim 1, wherein the average channel quality information is transmitted in a time period, and is transmitted using resources for transmitting the channel-by-channel quality information.

5. The method of claim 4, wherein the measuring the average channel quality information comprises computing the average channel quality information by excluding a sub-band channel quality value transmitted in previous channel quality information.

6. A scheduling method for use in a base station of a wireless communication system based on Orthogonal Frequency Division Multiple Access (OFDMA) for measuring and feeding back channel quality information of sub-bands with better channel quality information and average channel quality information for a total band, the method comprising:

determining whether an associated sub-band can be allocated to an associated mobile station when channel quality information for sub-bands is included;

setting a data transmission in adaptive modulation and demodulation mode and setting a data transmission rate according to the channel quality information, when the associated sub-band can be allocated; and

setting a data transmission in diversity mode and setting a data transmission rate according to average channel quality information for a total band, when the associated sub-band cannot be allocated.

7. The method of claim 6, further comprising setting power of a control channel to be transmitted to each mobile station using the average channel quality information for the total band.

8. The method of claim 7, wherein when channel quality information of a sub-band for which the average channel quality information is reported is comprised, an average channel value for the total band is set again by excluding the channel quality information of the sub-band.

9. The method of claim 6, wherein when a data transmission is set in the adaptive modulation and demodulation mode, power of data to be transmitted is set by sub-bands selected from among reported sub-bands.

10. The method of claim 6, wherein a data transmission is set in the diversity mode, power of data to be transmitted is set by an average channel value for the total band.

11. An apparatus for feeding back channel quality information from a mobile station in a wireless communication system based on Orthogonal Frequency Division Multiple Access (OFDMA), comprising:

a controller for measuring sub-band-by-sub-band channel quality information, generating channel-by-channel quality information of a number of channels in order of sub-bands with better channel quality information, and measuring and generating average channel quality information for a total band in the OFDMA wireless communication system;

a modem for encoding and modulating information output from the controller; and

a transmitter for configuring information output from the modem in a physical channel, performing a band up-conversion process for the physical channel, and transmitting the physical channel.

12. The apparatus of claim 11, wherein the controller alternately transmits the sub-band-by-sub-band channel quality information and the average channel quality information for the total band in a unit of a time period.

13. The apparatus of claim 11, wherein the controller simultaneously transmits the sub-band-by-sub-band channel quality information and the average channel quality information for the total band.

14. The apparatus of claim 11, wherein the controller sets channel quality by excluding channel quality information of a reported sub-band when the average channel quality information for the total band is set.

15. An apparatus for receiving channel quality information feedback and performing scheduling in a base station of a wireless communication system based on Orthogonal Frequency Division Multiple Access (OFDMA), comprising:

a channel quality information receiver for receiving, demodulating, and decoding channel quality information received from a mobile station;

a controller for extracting average channel quality information for a total band and sub-band index information mapped to best channel quality of a particular mobile station on a basis of information from the channel quality information receiver, allocating a channel to each mobile station in adaptive modulation and demodulation mode using sub-band indices mapped to the best channel quality and a priority of each mobile station after collecting scheduling information, and performing scheduling using average channel quality information of mobile stations for which allocation is impossible with respect to a sub-band of the best channel quality or only the average channel quality information for the total band; and

a data channel configuration unit for configuring and transmitting a data channel on a basis of information controlled in the controller.

16. The apparatus of claim 15, wherein the controller outputs a data control channel power control signal for controlling power of a control channel for providing control information of data to be transmitted using the average channel quality information for the total band, and wherein the apparatus further comprises:

a control channel configuration unit for setting power of the control information of the data channel to be transmitted using the data control channel power control signal and transmitting the control information.

17. The apparatus of claim 16, wherein the controller computes average channel quality by excluding power of a reported sub-band when the data control channel power control signal is generated if computation has been performed by including power of the sub-band for which the received average channel quality information for the total band has been reported.

18. A method for feeding back channel quality information from a mobile station in a wireless communication system based on Orthogonal Frequency Division Multiple Access (OFDMA) for configuring a sub-band with one or more orthogonal frequency resources, transmitting a pilot signal using the orthogonal frequency resources in a time period, transmitting forward data using the orthogonal frequency resources, and receiving channel quality information in a reverse direction, the method comprising:

receiving the pilot signal;

measuring channel quality information of sub-bands and average channel quality for a total band;

transmitting, in at least one of a plurality of slots, channel-by-channel quality information and indices of a number of sub-bands in order of better channel quality information; and

transmitting, in at least one of the plurality of slots, the average channel quality information for the total band.

19. The method of claim 18, wherein the channel-by-channel quality information and the average channel quality information are transmitted in every slot.

20. The method of claim 18, wherein the average channel quality information is transmitted in a time period, and is transmitted using resources for transmitting the channel-by-channel quality information.