Method for transmitting a signal in multi-antenna communication system

• US 9,577,735 B2
• Filed: 04/21/2008
• Issued: 02/21/2017
• Est. Priority Date: 04/19/2007
• Status: Active Grant

• Current Assignee: LG Electronics, Inc. (LG Corporation)
• Original Assignee: LG Electronics, Inc. (LG Corporation)
• Inventors: Lee, Moon Il, Lee, Wook Bong, Ihm, Bin Chul, Ko, Hyun Soo, Chung, Jae Hoon
• Primary Examiner(s): Liu, Shuwang
• Assistant Examiner(s): AHN, SUNG S
• Application Number:
  US12/106,980
• Publication Number:
  US 20080267318A1
• Time in Patent Office: 3,228 Days
• Field of Search: 375/299, 375/334, 375/328, 375/304
• US Class Current: 1/1
• CPC Class Codes: H04B 7/0671 using different delays between antennas
• CPC Class Codes: H04B 7/0689 using different transmission schemes, at least one of them being a diversity transmission scheme
• CPC Class Codes: H04B 7/0691 using subgroups of transmit antennas
• CPC Class Codes: H04B 7/12 Frequency diversity

Abstract

A multi-input multi-output (MIMO) system considers either reliability for each antenna or a time/frequency location, and transmits a signal at an unequal ratio for each antenna according to the consideration result. The method for use in the MIMO system including multiple antennas includes processing a signal according to an unequal ratio transmission scheme employing the multiple antennas at an unequal ratio, and transmitting the processed signal via the multiple antennas.

Claims

1. A method for transmitting one or more signals in a Multiple-Input Multiple-Output (MIMO) system including four antennas arranged as a first antenna set and a second antenna set, the method comprising:

mapping data bits to data symbols;

converting the data symbols into space-time signals; and

transmitting reference signals and the space-time signals via the four antennas,

wherein a number of the space-time signals transmitted at a specific orthogonal frequency divisional multiplexing (OFDM) symbol region in a subframe from the first antenna set is twice a number of the space-time signals transmitted at the specific OFDM symbol region in the subframe from the second antenna set,

wherein the first antenna set and the second antenna set transmit the same number of the reference signals at the specific OFDM symbol region,

wherein the specific OFDM symbol region is configured with 3 OFDM symbols from a first OFDM symbol of the subframe,

wherein the first antenna set has two antennas of the four antennas and the second antenna set has the other two of the four antennas, and

wherein the space-time signals are alternately transmitted through the first antenna set and the second antenna set in the specific OFDM symbol region of the subframe.

2. The method according to claim 1, wherein the space-time signals are transmitted according to a predefined pattern.

3. The method according to claim 2, wherein the data symbols are converted into the space-time signals by using a pre-coding matrix.

4. The method according to claim 3, wherein the pre-coding matrix includes at least a Time-Switched Transmit Diversity (TSTD) scheme or a Frequency-Switched Transmit Diversity (FSTD) scheme.

5. The method according to claim 3 wherein the first antenna set has higher reliability than the second antenna set.

6. A transmission end for transmitting one or more signals in a Multiple-Input Multiple-Output (MIMO) system including four antennas arranged as a first antenna set and a second antenna set, the transmission end comprising:

a mapper configured to map data bits to data symbols;

a spatial processing block configured to convert the data symbols into space-time signals; and

a transmitter configured to transmit reference signals and the space-time signals via the four antennas,

wherein a number of the space-time signals transmitted at a specific orthogonal frequency divisional multiplexing (OFDM) symbol region in a subframe from the first antenna set is twice a number of the space-time signals transmitted at the specific OFDM symbol region in the subframe from the second antenna set,

wherein the first antenna set and the second antenna set transmit the same number of the reference signals at the specific OFDM symbol region,

wherein the specific OFDM symbol region is configured with 3 OFDM symbols from a first OFDM symbol of the subframe,

wherein the first antenna set has two antennas of the four antennas and the second antenna set has the other two of the four antennas, and

wherein the space-time signals are alternately transmitted through the first antenna set and the second antenna set in the specific OFDM symbol region of the subframe.

7. The transmission end according to claim 6, wherein the space-time signals are transmitted according to a predefined pattern.

8. The transmission end according to claim 7, wherein the spatial processing block is further configured to convert the data symbols into the space-time signals by using a pre-coding matrix.

9. The transmission end according to claim 8, wherein the pre-coding matrix includes at least a Time-Switched Transmit Diversity (TSTD) scheme or a Frequency-Switched Transmit Diversity (FSTD) scheme.

10. The transmission end according to claim 8, wherein the first antenna set has higher reliability than the second antenna set.