Method for uplink scheduling in communication system using frequency hopping-orthogonal frequency division multiple access scheme

• US 20060094372A1
• Filed: 10/28/2005
• Published: 05/04/2006
• Est. Priority Date: 10/29/2004
• Status: Abandoned Application

• Current Assignee: Korea Advanced Institute of Science and Technology, Samsung Electronics Co. Ltd.
• Original Assignee: Korea Advanced Institute of Science and Technology, Samsung Electronics Co. Ltd.
• Inventors: Lee, Ok-Seon, Kim, Yung-Soo, Ahn, Woo-Geun, Kim, Hyung-Myung, Park, Seung-Young, Lee, Yeon-Woo, Oh, Hye-Ju, Kang, Tae-Sung
• Application Number:
  US11/262,216
• Publication Number:
  US 20060094372A1
• Time in Patent Office: Days
• US Class Current: 455/67.13
• CPC Class Codes: H04L 1/0003 by switching between different modulation schemes
• CPC Class Codes: H04L 1/0009 by adapting the channel coding H04L1/1812 takes precedence
• CPC Class Codes: H04L 1/0015 characterised by the adaptation strategy
• CPC Class Codes: H04L 5/023 Multiplexing of multicarrier modulation signals multicarrier modulation H04L27/2601

Abstract

Disclosed is a method for uplink scheduling in a communication system. The method for uplink scheduling in a communication system having a cellular structure hopping between sub-channels according to a predetermined rule whenever a signal is transmitted The communication system dividing a whole frequency band into a plurality of sub-carrier bands and including the sub-channels which are sets of the sub-carrier bands. The method includes determining a number of sub-channels to be allocated to a mobile station such that throughput of the mobile station is maximized based on a first predetermined condition in which a mobile station having a superior channel state is allocated with a greater number of sub-channels than a mobile station having an inferior channel state, and determining a modulation and coding scheme level according to a signal-to-interference and noise ratio (SINR) of a downlink channel reported by the mobile station based on a second predetermined condition capable of improving a channel state of the mobile station having an inferior channel state.

Claims

1. A method for uplink scheduling in a communication system having a cellular structure hopping between sub-channels according to predetermined conditions whenever a signal is transmitted, the communication system dividing a whole frequency band into a plurality of sub-carrier bands and including the sub-channels which are sets of the sub-carrier bands, the method comprising the steps of:

determining a number of sub-channels to be allocated to a mobile station such that throughput of the mobile station is maximized based on a first condition in which a mobile station having a superior channel state is allocated with a greater number of sub-channels than the number of sub-channels allocated to a mobile station having an inferior channel state; and

determining a modulation and coding scheme level according to a signal-to-interference and noise ratio (SINR) of a downlink channel reported by the mobile station based on a second condition capable of improving a uplink/downlink channel state of the mobile station having an inferior channel state.

2. The method as claimed in claim 1, wherein the number of the sub-channels allocated to each of the mobile stations is lower than or equal to a total number of sub-channels preset in a system.

3. The method as claimed in claim 2, further comprising the steps of:

temporarily decreasing the number of the sub-channels allocated to each mobile station, if a sum of the numbers of the sub-channels determined according to the mobile stations is greater than the total numbers of sub-channels;

calculating throughput of each mobile station according to the decreased number of the sub-channels;

selecting a mobile station having minimum throughput reduction; and

decreasing a number of sub-channels to be allocated to the mobile station such that the sum of the numbers of the sub-channels determined according to the mobile stations is less than or equal to the total number of sub-channels.

4. The method as claimed in claim 1, wherein the modulation and coding scheme level and the number of the sub-channels allocated to each mobile station are determined based on the first condition and the second condition are defined by,

5. The method as claimed in claim 4, wherein an amount of power to be allocated to a single sub-channel of the mobile station is less than or equal to a total amount of power of a cell divided by the total number of sub-channels in the cell.

6. A method for uplink scheduling in a communication system having a cellular structure using sub-channels to transmit signals according to predetermined conditions, the communication system dividing a whole frequency band into a plurality of sub-carrier bands and including the sub-channels which are sets of the sub-carrier bands, the method comprising the steps of:

estimating an amount of signal interference exerted on a mobile station located in a predetermined cell by neighboring cells;

estimating an average amount of signal interference by dividing a total amount of signal interference of all mobile stations existing in the predetermined cell by the number of the neighboring cells;

adding a first offset value to the amount of signal interference experienced by the mobile station due to the neighboring cells and averaging signal-to-interference and noise ratio (SINR) values of overall cells such that the averaged signal-to-interference and noise ratio (SINR) value approximates the estimated amount of signal interference; and

determining a transmit power of the mobile station corresponding to the averaged signal-to-interference and noise ratio (SINR) value.

7. The method as claimed in claim 6, wherein the first offset value is used to increment or decrement a value of the amount of signal interference.

8. The method as claimed in claim 6, further comprising the steps of:

estimating a receive signal power allocated to the mobile station; and

adding a total of all signal powers received by the neighboring cells by the mobile station to a second offset value and averaging signal-to-interference-and-noise ratio (SINR) values of overall cells such that the averaged signal-to-interference and noise ratio (SINR) value approximates the estimated average amount of signal interference.

9. The method as claimed in claim 8, wherein the second offset value is used to increment or decrement value of the estimated receive signal power.

10. The method as claimed in claim 6, wherein the base station determines a maximum transmit power P of each mobile station for an N^th frame using the following equation,

11. A method for uplink scheduling in a communication system having a cellular structure using sub-channels to transmit signals according to predetermined conditions, the communication system dividing a whole frequency band into a plurality of sub-carrier bands and including the sub-channels which are sets of the sub-carrier bands, the method comprising the steps of:

estimating an amount of signal interference exerted on a mobile station existing in a predetermined cell by neighboring cells;

estimating an average amount of signal interference by dividing a total amount of signal interference of all mobile stations existing in the predetermined cell by the number of the neighboring cells;

adding a first offset value to the amount of signal interference experienced by the mobile station due to the neighboring cells and averaging signal-to-interference and noise ratio (SINR) values of overall cells such that the averaged signal-to-interference and noise ratio (SINR) value approximates the estimated amount of signal interference;

determining a transmission power of the mobile station corresponding to the averaged signal-to-interference and noise ratio (SINR) value;

determining a number of sub-channels to be allocated to a mobile station such that throughput of the mobile station is maximized based on a condition in which a mobile station having a superior channel state is allocated with a greater number of sub-channels than the number of sub-channels allocated to a mobile station having an inferior channel state according to the determined transmit power of the mobile station; and

determining a modulation and coding scheme level according to a signal-to-interference and noise ratio (SINR) of the mobile station based on a predetermined condition so as to improve a channel state of the mobile station having a channel state which is requires improvement.