8-Transmit antenna reference signal design for downlink communications in a wireless system

• US 20100104034A1
• Filed: 10/02/2009
• Published: 04/29/2010
• Est. Priority Date: 10/27/2008
• Status: Active Grant

• Current Assignee: Samsung Electronics Co. Ltd.
• Original Assignee: Samsung Electronics Co. Ltd.
• Inventors: Khan, Farooq, Abu-Surra, Shadi, Zhang, Jianzhong, Nam, Young-Han
• Granted Patent: US 8,340,199 B2
• Time in Patent Office: Days
• US Class Current: 375/260
• CPC Class Codes: H04L 5/0007 the frequencies being orthogonal, e.g. OFDM(A), DMT
• 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

Systems and methods are disclosed for mapping reference signals for antenna ports in a plurality of resource blocks among resource blocks in a subframe within an orthogonal frequency division multiplexing (OFDM) communication system. This method includes selecting at least one predetermined resource elements for transmitting in the plurality of resource blocks using a first number of antenna ports. This method also includes selecting a second number of antenna ports and mapping a plurality of reference signals relating to the second number of antenna ports using a second number of OFDM symbols.

Claims

1. A method of mapping reference signals for antenna ports in a plurality of resource blocks among resource blocks in a subframe within an orthogonal frequency division multiplexing (OFDM) communication system, the method comprising:

selecting at least one predetermined resource elements for transmitting in the plurality of resource blocks using a first number of antenna ports, wherein the first number of antenna ports are used to transmit a first number of reference signals using at least one predetermined mapping scheme, and wherein the at least one predetermined resource elements comprise a first number of OFDM symbols that are transmitted using the first number of antenna ports;

selecting a second number of antenna ports; and

mapping a plurality of reference signals relating to the second number of antenna ports using a second number of OFDM symbols, wherein each of the reference signals for the second number of antenna ports are mapped in one of the resource elements comprising each of the second number of OFDM symbols.

2. The method of claim 1, wherein the at least one predetermined resource element is selected according to at least one Long Term Evolution (LTE) standard.

3. The method of claim 1, further comprising staggering a position of reference signal symbols of each of the second number of antenna ports in a subcarrier domain and in an OFDM-symbol domain.

4. The method of claim 3, wherein the second number of antenna ports is an even number.

5. The method of claim 3, wherein the staggering comprising mapping the reference signal symbols in identical subcarriers of each of the second number of OFDM symbols.

6. The method of claim 3, wherein the staggering comprising mapping reference signal symbols in different subcarriers, wherein position differences are identical among the subcarriers containing reference signals in each of the second number of OFDM symbols.

7. The method of claim 5, wherein a number of the identical subcarriers is less than or equal to the second number of reference signals.

8. The method of claim 1, wherein the method is used in subframes not comprising synchronization signals.

9. The method of claim 1, wherein the method is used in resource blocks not comprising synchronization signals.

10. A system, comprising:

A processor that maps additional reference signals for a second number of antenna ports in a plurality of resource blocks among the resource blocks in a subframe within an orthogonal frequency division multiplexing (OFDM) communication system, wherein the processor is further configured to;

select at least one predetermined resource element for transmitting in the plurality of resource blocks using a first number of antenna ports, wherein the first number of antenna ports are used to transmit a first number of reference signals using at least one predetermined mapping scheme, and wherein the at least one predetermined resource element comprises a first number of OFDM symbols that are transmitted using the first number of antenna ports;

select a second number of antenna ports; and

map a plurality of references signal relating to the second number of antenna ports using a second number of OFDM symbols, wherein the reference signals for the second number of antenna ports are mapped in the resource elements comprising each of the second number of OFDM symbols; and

a transmitter that transmits the signals created by the processor over the plurality of antenna ports.

11. The system of claim 10, wherein the at least one predetermined resource elements are selected according to at least one Long Term Evolution (LTE) standard.

12. The system of claim 10, wherein the processor staggers a position of reference signal symbols of each of the second number of antenna ports in a subcarrier domain and in an OFDM-symbol domain.

13. The system of claim 12, wherein the second number of antenna ports is an even number.

14. The system of claim 12, wherein the staggering comprising mapping the reference signal symbols in identical subcarriers of each of the second number of OFDM symbols.

15. The system of claim 12, wherein the staggering comprising mapping reference signal symbols in different subcarriers , wherein position differences are identical among the subcarriers containing reference signals in each of the second number of OFDM symbols.

16. The system of claim 14, wherein a number of the identical subcarriers is less than or equal to the second number of reference signals.

17. The system of claim 10, wherein the processor selects a first number of subcarriers, wherein the first number of subcarriers is greater than the first number of antenna ports.

18. The system of claim 16, wherein the first number of reference signals are mapped according to an LTE mapping scheme.

19. The system of claim 10, wherein the method is used in subframes not comprising synchronization signals.

20. The system of claim 10, wherein the system is used in resource blocks not comprising synchronization signals.