Apparatus and method for transmitting pilot signal in a BWA communication system using transmit antennas

• US 7,826,344 B2
• Filed: 07/07/2005
• Issued: 11/02/2010
• Est. Priority Date: 07/07/2004
• Status: Active Grant

• Current Assignee: Samsung Electronics Co. Ltd.
• Original Assignee: Samsung Electronics Co. Ltd.
• Inventors: Maeng, Seung-Joo, Jeong, Hong-Sil, Jeon, Jae-Ho, Joo, Pan-Yuh, Chae, Chan-Byoung, Ko, Kyun-Byoung, Oh, Jeong-Tae, Yun, Sung-Ryul, Roh, Won-Il
• Primary Examiner(s): Moe; Aung S
• Assistant Examiner(s): Alia; Curtis A
• Application Number:
  US11/176,930
• Publication Number:
  US 20060023680A1
• Time in Patent Office: 1,944 Days
• Field of Search: 370276-278, 370/310, 370/314, 370/340, 370/343, 370/345, 370208-210, 455/42, 455/45, 455/46, 455/500, 455/512, 455/73, 455/103, 455/104, 375/219, 375/260
• US Class Current: 370/208
• CPC Class Codes: H04B 7/0613 using simultaneous transmission H04B7/0686 takes precedence
• CPC Class Codes: H04L 1/0066 Parallel concatenated codes
• CPC Class Codes: H04L 1/007 Unequal error protection for format H04L1/0078; for codes per se H03M13/35
• CPC Class Codes: H04L 1/0071 Use of interleaving interleaving per se H03M13/27
• CPC Class Codes: H04L 1/0668 Orthogonal systems, e.g. using Alamouti codes
• CPC Class Codes: H04L 25/0226 sounding signals per se
• CPC Class Codes: H04L 5/0023 Time-frequency-space
• CPC Class Codes: H04L 5/0048 Allocation of pilot signals, i.e. of signals known to the receiver

Abstract

A method and system for transmitting reference signals in a BWA communication system using a first transmit antenna, a second transmit antenna, and a plurality of sub-carriers. Each of the sub-carriers occupies a sub-frequency domain. In the method, reference signals for identifying a first transmit antenna are transmitted through a second predetermined number of sub-carriers in a first mini sub-channel transmitted through the first transmit antenna and occupied by a predetermined time domain and sub-frequency domains of a first predetermined number of sub-carriers, and reference signals for identifying a second transmit antenna are transmitted through the second predetermined number of the sub-carriers in a second mini sub-channel transmitted through the second transmit antenna and occupied by the time domain and the sub-frequency domains of the first predetermined number of sub-carriers.

Claims

1. A method for transmitting reference signals in a Broadband Wireless Access (BWA) communication system including a first transmit antenna, a second transmit antenna, and a plurality of sub-carriers, each of the sub-carriers occupying a sub-frequency domain, the method comprising the steps of:

(1) transmitting reference signals for identifying the first transmit antenna through a second predetermined number of sub-carriers in a first mini sub-channel, the first mini sub-channel being transmitted through the first transmit antenna and occupied by a predetermined time domain and sub-frequency domains of a first predetermined number of sub-carriers, wherein, after the second predetermined number of sub-carriers in the first mini sub-channel are truncated by using a truncation scheme, the reference signals are inserted in the truncated second predetermined number of sub-carriers in the first mini-sub-channel and transmitted; and

(2) transmitting reference signals for identifying the second transmit antenna through the second predetermined number of the sub-carriers in a second mini sub-channel, the second mini sub-channel being transmitted through the second transmit antenna and occupied by the time domain and the sub-frequency domains of the first predetermined number of sub-carriers wherein, after the second predetermined number of sub-carriers in the second mini-sub-channel are truncated by using the truncation scheme, the reference signals are inserted in the truncated second predetermined number of sub-carriers in the second mini sub-channel and transmitted,

wherein the sub-carriers through which the reference signals for identifying the first transmit antenna are transmitted comprise sub-frequency domains different from the sub-frequency domains occupied by the sub-carriers through which the reference signals for identifying the second transmit antenna are transmitted,

wherein transmitting the reference signals for identifying the first transmit antenna further comprises transmitting null data in the first mini sub-channel through sub-carriers including sub-frequency domains that are identical to the sub-frequency domains of the sub-carriers for transmitting the reference signal for identifying the second transmit antenna,

wherein transmitting the reference signals for identifying the second transmit antenna further comprises transmitting null data in the second mini sub-channel through sub-carriers including sub-frequency domains that are identical to the sub-frequency domains of the sub-carriers for transmitting the reference signals for identifying the first transmit antenna,

wherein the reference signals for identifying the first and second transmit antennas are inserted into sub-carriers that were previously allocated to data tones before the truncation by using the truncation scheme, and

wherein coded symbols to be transmitted include systematic symbols and parity symbols, and only the parity symbols arc truncated according to the truncation scheme.

2. The method as claimed in claim 1, further comprising transmitting information data through remaining sub-carriers excluding sub-carriers including sub-frequency domains that are identical to the sub-carriers for transmitting the reference signals for identifying the second transmit antenna from among sub-carriers excluding the sub-carriers that transmit the reference signals for identifying the first transmit antenna, in the first mini sub-channel.

3. The method as claimed in claim 1, further comprising transmitting information data through remaining sub-carriers excluding sub-carriers including sub-frequency domains that are identical to the sub-carriers for transmitting the reference signals for identifying the first transmit antenna from among sub-carriers excluding the sub-carriers that transmit the reference signals for identifying the second transmit antenna, in the second mini sub-channel.

4. The method as claimed in claim 1, wherein information data to be transmitted is encoded according to a first predetermined coding scheme, which includes a Convolutional Turbo Coding (CTC) scheme.

5. The method as claimed in claim 1, wherein symbols to be transmitted are encoded according to a second predetermined coding scheme, which includes a Space Time Block Code (STBC) scheme.

6. A method for transmitting reference signals in a Broadband Wireless Access (BWA) communication system including a first transmit antenna, a second transmit antenna, and a plurality of sub-carriers, each of the sub-carriers occupying a sub-frequency domain, the method comprising the steps of:

generating coded symbols by coding information data to be transmitted according to a first predetermined coding scheme;

generating coded symbols to be transmitted through the first transmit antenna and coded symbols to be transmitted through the second transmit antenna by coding the coded symbols according to a second predetermined coding scheme;

inserting reference signals for identifying the first transmit antenna into a second predetermined number of sub-carriers in a first mini sub-channel, the first mini sub-channel being transmitted through the first transmit antenna and occupied by a predetermined time domain and sub-frequency domains of a first predetermined number of sub-carriers;

inserting reference signals for identifying the second transmit antenna into the second predetermined number of the sub-carriers in a second mini sub-channel, the second mini sub-channel being transmitted through the second transmit antenna and occupied by the time domain and the sub-frequency domains of the first predetermined number of sub-carriers;

inserting null data into sub-carriers including sub-frequency domains that are identical to the sub-frequency domains of the sub-carriers for transmitting the reference signals for identifying the second transmit antenna from among sub-carriers excluding the sub-carriers, which transmit the reference signals for identifying the first transmit antenna, in the first mini sub-channel;

inserting null data into sub-carriers including sub-frequency domains, which are identical to the sub-frequency domains of the sub-carriers for transmitting the reference signals for identifying the first transmit antenna from among sub-carriers excluding the sub-carriers that transmit the reference signals for identifying the second transmit antenna, in the second mini sub-channel;

inserting the coded symbols to be transmitted through the first transmit antenna into sub-carriers truncated according to a truncation scheme, which exclude the sub-carriers including the reference signals and the null data in the first mini sub-channel;

inserting the coded symbols to be transmitted through the second transmit antenna into sub-carriers truncated according to the truncation scheme, which exclude the sub-carriers including the reference signals and the null data in the second mini sub-channel;

processing signals of the first mini sub-channel to transmit the processed signals through the first transmit antenna; and

processing signals of the second mini sub-channel to transmit the processed signals through the second transmit antenna,

wherein the reference signals for identifying the first and second transmit antennas are inserted into sub-carriers that were previously allocated to data tones before the truncation by using the truncation scheme, and

wherein the coded symbols to be transmitted include systematic symbols and parity symbols, and only the parity symbols are truncated according to the truncation scheme.

7. The method as claimed in claim 6, wherein the sub-carriers through which the reference signals for identifying the first transmit antenna are transmitted comprise sub-frequency domains different from sub-frequency domains occupied by the sub-carriers through which the reference signals for identifying the second transmit antenna are transmitted.

8. The method as claimed in claim 7, wherein inserting the coded symbols to be transmitted through the first transmit antenna comprises:

inserting the coded symbols to be transmitted through the first transmit antenna in a sequence from a coded symbol representing important information of a highest priority to remaining coded symbols into the sub-carriers excluding the sub-carriers including the reference signals and the null data in the first mini sub-channel.

9. The method as claimed in claim 7, wherein inserting the coded symbols to be transmitted through the second transmit antenna comprises:

inserting the coded symbols to be transmitted through the second transmit antenna in a sequence from a coded symbol representing important information of a highest priority to remaining coded symbols into the sub-carriers excluding the sub-carriers including the reference signals and the null data in the second mini sub-channel.

10. The method as claimed in claim 6, wherein the first coding scheme includes a Convolutional Turbo Coding (CTC) scheme.

11. The method as claimed in claim 10, wherein, in inserting the coded symbols to be transmitted through the first transmit antenna, the coded symbols to be transmitted through the first transmit antenna comprise the systematic symbols and the parity symbols, and the systematic symbols are first inserted when the coded symbols are sequentially inserted into the sub-carriers excluding the sub-carriers including the reference signals and the null data in the first mini sub-channel.

12. The method as claimed in claim 10, wherein, in inserting the coded symbols to be transmitted through the second transmit antenna, the coded symbols to be transmitted through the second transmit antenna comprise the systematic symbols and the parity symbols, and the systematic symbols are first inserted when the coded symbols are sequentially inserted into the sub-carriers excluding the sub-carriers including the reference signals and the null data in the second mini sub-channel.

13. The method as claimed in claim 6, wherein the second coding scheme includes a Space Time Block Code (STBC) coding scheme.

14. An apparatus for transmitting reference signals in a Broadband Wireless Access (BWA) communication system using a first transmit antenna, a second transmit antenna, and a plurality of sub-carriers, each of the sub-carriers occupying a sub-frequency domain, the apparatus comprising:

a first transmitter for transmitting reference signals for identifying the first transmit antenna through a second predetermined number of sub-carriers in a first mini sub-channel, the first mini sub-channel being transmitted through the first transmit antenna and occupied by a predetermined time domain and sub-frequency domains of a first predetermined number of sub-carriers, wherein, after the second predetermined number of sub-carriers in the first mini-sub-channel are truncated by using a truncation scheme, the reference signals are inserted in the truncated second predetermined number of sub-carriers in the first mini-sub-channel and transmitted; and

a second transmitter for transmitting reference signals for identifying the second transmit antenna through the second predetermined number of the sub-carriers in a second mini sub-channel, the second mini sub-channel being transmitted through the second transmit antenna and occupied by the time domain and the sub-frequency domains of the first predetermined number of sub-carriers, wherein, after the second predetermined number of sub-carriers in the second mini-sub-channel are truncated by using the truncation scheme, the reference signals are inserted in the truncated second predetermined number of sub-carriers in the second mini-sub-channel and transmitted,

wherein the sub-carriers through which the reference signals for identifying the first transmit antenna are transmitted comprise sub-frequency domains different from sub-frequency domains occupied by the sub-carriers through which the reference signals for identifying the second transmit antenna are transmitted,

wherein the first transmitter transmits null data in the first mini sub-channel through sub-carriers including sub-frequency domains that are identical to the sub-frequency domains of the sub-carriers for transmitting the reference signals for identifying the second transmit antenna,

wherein the second transmitter transmits null data in the second mini sub-channel through sub-carriers including sub-frequency domains, which are identical to the sub-frequency domains of the sub-carriers for transmitting the reference signal for identifying the first transmit antenna, and

wherein the reference signals for identifying the first and second transmit antennas are inserted into sub-carriers that were previously allocated to data tones before the truncation by using the truncation scheme, and

wherein coded symbols to be transmitted include systematic symbols and parity symbols, and only the parity symbols are truncated according to the truncation scheme.

15. The apparatus as claimed in claim 14, wherein the first transmitter transmits information data through remaining sub-carriers excluding sub-carriers comprising sub-frequency domains that are identical to the sub-frequency domains of the sub-carriers for transmitting the reference signals for identifying the second transmit antenna from among sub-carriers excluding the sub-carriers, which transmit the reference signals for identifying the first transmit antenna, in the first mini sub-channel.

16. The apparatus as claimed in claim 14, wherein the second transmitter transmits information data through remaining sub-carriers excluding sub-carriers comprising sub-frequency domains that are identical to the sub-frequency domains of the sub-carriers for transmitting the reference signals for identifying the first transmit antenna from among sub-carriers excluding the sub-carriers that transmit the reference signals for identifying the second transmit antenna, in the second mini sub-channel.

17. The apparatus as claimed in claim 14, wherein information data to be transmitted is encoded according to a first predetermined coding scheme, which includes a Convolutional Turbo Coding (CTC) scheme.

18. The apparatus as claimed in claim 14, wherein symbols to be transmitted are encoded according to a second predetermined coding scheme, which includes a Space Time Block Code (STBC) scheme.

19. An apparatus for transmitting reference signals in a Broadband Wireless Access (BWA) communication system using a first transmit antenna, a second transmit antenna, and a plurality of sub-carriers, each of the sub-carriers occupying a sub-frequency domain, the apparatus comprising:

a first coder for generating coded symbols by coding information data to be transmitted according to a first predetermined coding scheme;

a second coder for coding the coded symbols according to a second predetermined coding scheme in order to generate coded symbols to be transmitted through the first transmit antenna and coded symbols to be transmitted through the second transmit antenna;

a first reference signal sub-carrier inserter for inserting reference signals for identifying the first transmit antenna into a second predetermined number of sub-carriers in a first mini sub-channel, the first mini sub-channel being transmitted through the first transmit antenna and occupied by a predetermined time domain and sub-frequency domains of a first predetermined number of sub-carriers;

a first sub-carrier mapper for inserting null data into sub-carriers including sub-frequency domains that are identical to sub-frequency domains of the sub-carriers for transmitting the reference signals for identifying the second transmit antenna from among sub-carriers excluding the sub-carriers, which transmit the reference signals for identifying the first transmit antenna, in the first mini sub-channel, and inserting the coded symbols to be transmitted through the first transmit antenna into sub-carriers truncated according to a truncation scheme that exclude the sub-carriers including the reference signals and the null data in the first mini sub-channel;

a second reference signal sub-carrier inserter for inserting reference signals for identifying the second transmit antenna into the second predetermined number of the sub-carriers in a second mini sub-channel, the second mini sub-channel being transmitted through the second transmit antenna and occupied by the time domain and the sub-frequency domains of the first predetermined number of sub-carriers;

a second sub-carrier mapper for inserting null data into sub-carriers including sub-frequency domains that are identical to sub-frequency domains of the sub-carriers for transmitting the reference signals for identifying the first transmit antenna from among sub-carriers excluding the sub-carriers that transmit the reference signals for identifying the second transmit antenna, in the second mini sub-channel, and inserting the coded symbols to be transmitted through the second transmit antenna into sub-carriers truncated according to the truncation scheme that exclude the sub-carriers including the reference signals and the null data in the second mini sub-channel;

a first transmitter for processing signals of the first mini sub-channel and transmitting the processed signals through the first transmit antenna; and

a second transmitter for processing signals of the second mini sub-channel and transmitting the processed signals through the second transmit antenna,

wherein the reference signals for identifying the first and second transmit antennas are inserted into sub-carriers that were previously allocated to data tones before the truncation by using the truncation scheme, and

wherein the coded symbols to be transmitted include systematic symbols and parity symbols, and only the parity symbols arc truncated according to the truncation scheme.

20. The apparatus as claimed in claim 19, wherein the sub-carriers through which the reference signals for identifying the first transmit antenna are transmitted comprise sub-frequency domains different from the sub-frequency domains occupied by the sub-carriers through which the reference signals for identifying the second transmit antenna are transmitted.

21. The apparatus as claimed in claim 20, wherein the first sub-carrier mapper inserts the coded symbols to be transmitted through the first transmit antenna in a sequence from a coded symbol representing important information of a highest priority to remaining coded symbols into the sub-carriers excluding the sub-carriers including the reference signals and the null data in the first mini sub-channel.

22. The apparatus as claimed in claim 20, wherein the second sub-carrier mapper inserts the coded symbols to be transmitted through the second transmit antenna in a sequence from a coded symbol representing important information of a highest priority to remaining coded symbols into the sub-carriers excluding the sub-carriers including the reference signals and the null data in the second mini sub-channel.

23. The apparatus as claimed in claim 19, wherein the first coding scheme comprises a Convolutional Turbo Coding (CTC) scheme.

24. The apparatus as claimed in claim 23, wherein the coded symbols to be transmitted through the first transmit antenna comprise the systematic symbols and the parity symbols, and wherein the first sub-carrier mapper first inserts the systematic symbols when sequentially inserting the coded symbols into the sub-carriers excluding the sub-carriers including the reference signals and the null data in the first mini sub-channel.

25. The apparatus as claimed in claim 23, wherein the coded symbols to be transmitted through the second transmit antenna comprise the systematic symbols and the parity symbols, and wherein the second sub-carrier mapper first inserts the systematic symbols when sequentially inserting the coded symbols into the sub-carriers excluding the sub-carriers including the reference signals and the null data in the second mini sub-channel.

26. The apparatus as claimed in claim 19, wherein the second coding scheme comprises a Space Time Block Code (STBC) coding scheme.