Apparatus and method for data transmission/reception using channel state information in wireless communication system

• US 7,596,133 B2
• Filed: 05/12/2005
• Issued: 09/29/2009
• Est. Priority Date: 05/12/2004
• Status: Active Grant

• Current Assignee: Samsung Electronics Co. Ltd., Seoul National University Industry Foundation (Seoul National University)
• Original Assignee: Samsung Electronics Co. Ltd., Seoul National University Industry Foundation (Seoul National University)
• Inventors: Kim, Jong-Won, Shin, Yo-An
• Primary Examiner(s): Ryman; Daniel J
• Assistant Examiner(s): OH, ANDREW CHUNG SUK
• Application Number:
  US11/128,925
• Publication Number:
  US 20050254461A1
• Time in Patent Office: 1,601 Days
• Field of Search: 370/329, 370/208, 370/334, 455/464, 375/144, 375/149
• US Class Current: 370/366
• CPC Class Codes: H04W 24/10 Scheduling measurement reports ; Arrangements for measurement reports
• CPC Class Codes: H04W 72/02 Selection of wireless resources by user or terminal
• CPC Class Codes: H04W 8/04 Registration at HLR or HSS [Home Subscriber Server]

Abstract

Disclosed is a method for transmitting and receiving data according to a channel state in a wireless communication system, the method includes measuring a characteristic of transmission channels used for data transmission and transmitting channel state information of the measured channel characteristic; and selecting sub-channels for data transmission according to the channel state information, and transmitting data through the selected sub-channels.

Claims

1. A method for allocating bits to sub-channels for data transmission in a wireless communication system, the method comprising the steps of:

(a) setting a number of bits allocated to all sub-channels to an initial value;

(b) calculating a number of sub-channels required for bit allocation;

(c) determining an encoding detection sequence for each subcarrier in a state in which the initial value is set;

(d) calculating a weight vector for all subcarriers according to the encoding detection sequence;

(e) determining a sub-channel with a least 2-Norm value from among all sub-channels by using the calculated weight vector;

(f) selecting the sub-channel with the least 2-Norm value for bit allocation; and

(g) allocating K bits to the selected sub-channel,

wherein steps (e), (f) and (g) are repeated until a number of selected sub-channels for the bit allocation satisfies D_ACBA=|R_b×

(R+Δ

R)<sup>−

1</sup>/K|,

where D_ACBArepresents a number of sub-channels to be allocated, R_b represents a number of information bits to be transmitted, R represents a channel code rate applied in a system that does not employ a bit allocation algorithm, K represents a number of bits per symbol applied in the system that does not employ a bit allocation algorithm, and Δ

R represents an increment of a channel code rate required to ensure a sub-channel for bit allocation.

2. The method as claimed in claim 1, wherein the selected sub-channel is excluded from a procedure for determining a sub-channel to which a next bit is allocated.

3. The method as claimed in claim 1, further comprising a step of performing an encoding detection by using a new set of weight vectors for a transmission antenna used for each subcarrier, after the step of allocating bits.

4. The method as claimed in claim 3, wherein the new set of weight vectors is a set of weight vectors for sub-channels except for an unused sub-channel when the unused sub-channel exists.

5. The method as claimed in claim 1, wherein transmission power for a sub-channel to which no bit has been allocated is zero.

6. The method as claimed in claim 1, wherein the bit allocation is performed based on delay time of feedback information when the bit allocation is actually applied to a system, and the delay time of feedback information is calculated by,

${\mathrm{DT}}_{\mathrm{Feedback}}=T_{\mathrm{processing}}+\frac{d}{v_L}$

where DT_Feedback represents delay time of feedback information, T_Processing represents a sum of operation time periods required in a transmission side and a reception side, ‘

d’

represents a distance between the transmission side and the reception side, and V_L represents the flux of light.

7. An apparatus for allocating bits to sub-channels for data transmission in a wireless communication system, comprising:

a bit allocation unit for repeatedly setting numbers of bits allocated to all sub-channels to an initial value, calculating a number of sub-channels required for bit allocation, determining an encoding detection sequence for each subcarrier in a state in which the initial value is set, calculating a weight vector for all subcarriers according to the determined encoding detection sequence, determining a sub-channel with a least 2-Norm value from among all the sub-channels by using the calculated weight vector, selecting the sub-channel with the least 2-Norm value for bit allocation, and allocating K bits to the selected sub-channels, until a number of selected sub-channels for the bit allocation satisfies D_ACBA=|R_b×

(R+Δ

R)<sup>−

1</sup>/K|, where D_ACBA represents a number of sub-channels to be allocated, R_b represents a number of information bits to be transmitted, R represents a channel code rate applied in a system that does not employ a bit allocation algorithm, K represents a number of bits per symbol applied in the system that does not employ the bit allocation algorithm, and Δ

R represents an increment of a channel code rate required for a sub-channel for bit allocation.

8. The apparatus as claimed in claim 7, wherein the selected sub-channel is excluded when determining a sub-channel to which a next bit is allocated.

9. The apparatus as claimed in claim 7, wherein an encoding detection is further performed using a new set of weight vectors for a transmission antenna used for each subcarrier after the bit allocation has been performed.

10. The apparatus as claimed in claim 9, wherein the new set of weight vectors is a set of weight vectors for sub-channels except for an unused sub-channel when the unused sub-channel exists.

11. The apparatus as claimed in claim 7, wherein transmission power for a sub-channel to which no bit has been allocated is zero.

12. The apparatus as claimed in claim 7, wherein the bit allocation is performed based on delay time of feedback information when the bit allocation is actually applied to a system, and the delay time of feedback information is calculated by,

${\mathrm{DT}}_{\mathrm{Feedback}}=T_{\mathrm{processing}}+\frac{d}{v_L}$

where DT_Feedback represents delay time of feedback information, T_Processing represents a sum of operation time periods required in a transmission side and a reception side, d represents a distance between the transmission side and the reception side, and V_L represents the flux of light.