METHOD AND APPARATUS FOR ANTENNA DIVERSITY IN MULTI-INPUT MULTI-OUTPUT COMMUNICATION SYSTEMS

• US 20120120925A1
• Filed: 10/11/2011
• Published: 05/17/2012
• Est. Priority Date: 08/22/2005
• Status: Active Grant

• Current Assignee: Qualcomm, Inc.
• Original Assignee: Qualcomm, Inc.
• Inventors: Kadous, Tamer, Khandekar, Aamod, Gore, Dhananjay Ashok, Gorokhov, Alexei
• Granted Patent: US 9,660,776 B2
• Time in Patent Office: Days
• US Class Current: 370/336
• CPC Class Codes: H04B 7/0456 Selection of precoding matrices or codebooks, e.g. using matrices antenna weighting
• CPC Class Codes: H04B 7/061 using feedback from receiving side
• CPC Class Codes: H04B 7/0671 using different delays between antennas
• CPC Class Codes: H04B 7/0691 using subgroups of transmit antennas
• CPC Class Codes: H04B 7/0697 using spatial multiplexing
• CPC Class Codes: H04L 27/26035 Maintenance of orthogonality, e.g. for signals exchanged between cells or users, or by using covering codes or sequences using different training sequence per antenna H04B7/0684; code allocation H04J13/16
• CPC Class Codes: H04L 5/0023 Time-frequency-space

Abstract

Transmission schemes that can flexibly achieve the desired spatial multiplexing order, spatial diversity order, and channel estimation overhead order are described. For data transmission, the assigned subcarriers and spatial multiplexing order (M) for a receiver are determined, where M≧1. For each assigned subcarrier, M virtual antennas are selected from among V virtual antennas formed with V columns of an orthonormal matrix, where V≧M. V may be selected to achieve the desired spatial diversity order and channel estimation overhead order. Output symbols are mapped to the M virtual antennas selected for each assigned subcarrier by applying the orthonormal matrix. Pilot symbols are also mapped to the V virtual antennas. The mapped symbols are provided for transmission from T transmit antennas, where T≧V. Transmission symbols are generated for the mapped symbols, e.g, based on OFDM or SC-FDMA. Different cyclic delays may be applied for the T transmit antennas to improve diversity.

Claims

1. An apparatus, comprising:

at least one processor configured to allocate different subcarriers to different antennas at different times; and

a memory coupled to the at least one processor.

2. The apparatus of claim 1, wherein the processor is further configured to map a traffic channel to a specific sequence of the different subcarriers at the different times.

3. The apparatus of claim 2, wherein the processor is further configured to transmit the traffic channel on only one of the different subcarriers at each time in the different times.

4. The apparatus of claim 1, further comprising at least one of a base station and a terminal, with which the apparatus of claim 1 is integrated.

5. A method, comprising:

allocating different subcarriers to different antennas at different times.

6. The method of claim 5, further comprising mapping a traffic channel to a specific sequence of the different subcarriers at the different times.

7. The method of claim 6, further comprising transmitting the traffic channel on only one of the different subcarriers at each time in the different times.

8. An apparatus, comprising:

means for allocating different subcarriers to different antennas at different times.

9. The apparatus of claim 8, further comprising means for mapping a traffic channel to a specific sequence of the different subcarriers at the different times.

10. The apparatus of claim 9, further comprising means for transmitting the traffic channel on only one of the different subcarriers at each time in the different times.

11. The apparatus of claim 8, further comprising at least one of a base station and a terminal, with which the apparatus of claim 8 is integrated.

12. A non-transitory computer-readable medium, comprising instructions stored thereon that, if executed by a processor, cause the processor to execute a method comprising allocating different subcarriers to different antennas at different times.

13. The non-transitory computer-readable medium of claim 12, wherein the method further comprises mapping a traffic channel to a specific sequence of the different subcarriers at the different times.

14. The non-transitory computer-readable medium of claim 13, wherein the method further comprises transmitting the traffic channel on only one of the different subcarriers at each time in the different times.

15. The non-transitory computer-readable medium of claim 12, further comprising at least one of a base station and a terminal, with which the, computer-readable medium of claim 12 is integrated.