FEEDBACK CHANNEL DESIGN FOR MULTIPLE-INPUT MULTIPLE-OUTPUT COMMUNICATION SYSTEMS

• US 20070195908A1
• Filed: 02/20/2007
• Published: 08/23/2007
• Est. Priority Date: 02/21/2006
• Status: Active Grant

• Current Assignee: Qualcomm, Inc.
• Original Assignee: Qualcomm, Inc.
• Inventors: Bhushan, Naga, Wei, Yongbin, Attar, Rashid Ahmed Akbar, Fan, Mingxi
• Granted Patent: US 8,396,152 B2
• Time in Patent Office: Days
• US Class Current: 375/267
• CPC Class Codes: H04B 7/0452 Multi-user MIMO systems
• CPC Class Codes: H04B 7/0626 Channel coefficients, e.g. channel state information [CSI]
• CPC Class Codes: H04B 7/063 Parameters other than those covered in groups H04B7/0623 - H04B7/0634, e.g. channel matrix rank or transmit mode selection
• CPC Class Codes: H04B 7/0639 Using selective indices, e.g. of a codebook, e.g. pre-distortion matrix index [PMI] or for beam selection
• CPC Class Codes: H04J 13/0044 OVSF [orthogonal variable spreading factor]
• CPC Class Codes: H04L 1/0002 by adapting the transmission rate
• CPC Class Codes: H04L 1/0025 Transmission of mode-switching indication
• CPC Class Codes: H04L 1/0028 Formatting
• CPC Class Codes: H04L 1/06 using space diversity
• CPC Class Codes: H04L 1/1671 the supervisory signal being transmitted together with control information
• CPC Class Codes: H04L 1/1812 Hybrid protocols; Hybrid automatic repeat request [HARQ]
• CPC Class Codes: H04L 25/0204 of multiple channels
• CPC Class Codes: H04L 25/0226 sounding signals per se
• CPC Class Codes: H04L 27/2613 Structure of the reference signals
• CPC Class Codes: H04L 27/26132 using repetition
• CPC Class Codes: H04L 5/0026 Division using four or more dimensions
• CPC Class Codes: H04L 5/0048 Allocation of pilot signals, i.e. of signals known to the receiver
• CPC Class Codes: H04L 5/023 Multiplexing of multicarrier modulation signals multicarrier modulation H04L27/2601
• CPC Class Codes: H04L 5/1438 Negotiation of transmission parameters prior to communication modified according to link quality H04L1/0001
• CPC Class Codes: H04W 28/06 Optimizing the usage of the radio link, e.g. header compression, information sizing , discarding information system modifying transmission characteristic according to link quality by modifying frame length H04L1/0007; dynamic adaptation of the packet size for flow control or congestion control H04L47/365
• CPC Class Codes: H04W 28/18 : Negotiating wireless communication parameters
• CPC Class Codes: H04W 48/08 : Access restriction or access information delivery, e.g. discovery data delivery signalling during connection H04W76/00
• CPC Class Codes: Y02D 30/70 : in wireless communication networks

Abstract

A data-optimized communication system provides support for legacy access terminals, such as access terminals operating under the 1xEV-DO standard. The system also supports multiple-input multiple-output (MIMO) communications with access terminals configured to support MIMO. A number of MIMO spatial signatures are predefined or negotiated. MIMO rank and an identifier of the spatial signature determined at the MIMO access terminal are sent on the I-Branch and Q-Branch of the existing 1xEV-DO structure. In one embodiment, 1-bit rank and 3-bit spatial signature are transmitted through the I-Branch as a 4-bit symbol, replacing the data rate control (DRC) channel. In another embodiment, a 4-bit spatial signature is transmitted through the I-Branch, also replacing the DRC channel. A 2-bit rank is transmitted together with a 4-bit DRC channel through the Q-Branch. The 2-bit rank and the DRC channel can be distinguished because they are sent using different orthogonal codeword Walsh covers.

Claims

1. A method of sending feedback from an access terminal (AT) to a base transceiver station (BTS) of a radio network configured to communicate with the access terminal using multiple-in multiple-out (MIMO) technique, the method comprising:

determining MIMO rank information of a first forward link between the BTS and the AT;

determining MIMO spatial signature information of the forward link; and

simultaneously transmitting

(1) the MIMO rank information and the MIMO spatial signature information on an In-Phase signal component of a reverse link between the BTS and the AT, and

(2) data rate control (DRC) information for a forward link on a Quadrature signal component of the reverse link.

2. The method of claim 1, wherein the radio network is configured to provide services to the AT and to at least one non-MIMO capable access terminal.

3. The method of claim 1, wherein the radio network is configured to provide services to the AT and to at least one non-MIMO capable access terminal, the AT and the at least one other non-MIMO access terminal being in the same sector.

4. The method of claim 1, wherein the radio network is a data-optimized radio network.

5. The method of claim 1, wherein the radio network is configured to provide services to non-MIMO capable access terminals.

6. The method of claim 1, wherein:

the MIMO rank information consists of one bit; and

the MIMO spatial signature information consists of three bits.

7. The method of claim 1, wherein:

the MIMO rank information comprises one bit;

the MIMO spatial signature information comprises three bits;

the DRC information comprises four bits; and

the MIMO rank information and the MIMO spatial signature information are transmitted on the In-Phase signal component as a four bit symbol.

8. The method of claim 1, further comprising:

estimating spatial physical channels between a plurality of transmit antennae of the BTS and a plurality of receive antennae of the AT, the pluralities of transmit and receive antennae being configured for MIMO communication on the first forward link, the step of estimating providing a plurality of estimates of the first forward link;

wherein;

the step of determining MIMO rank information is performed based on the plurality of estimates of the first forward link; and

the step of determining MIMO spatial signature information is performed based on the plurality of estimates of the first forward link.

9. An access terminal (AT) configured to communicate with a base transceiver station (BTS) of a radio network using multiple-in multiple-out (MIMO) technique, the access terminal comprising:

a receiver configured to receive forward link transmissions from the BTS;

a transmitter configured to send reverse link transmissions to the BTS;

a memory storing program code; and

a controller coupled to the receiver, the transmitter, and the memory, wherein the controller is configured to execute the program code to cause the AT to perform steps comprising;

determining MIMO rank information of a first forward link between the BTS and the AT;

determining MIMO spatial signature information of the forward link; and

simultaneously transmitting

(1) the MIMO rank information and the MIMO spatial signature information on an In-Phase signal component of a reverse link between the BTS and the AT, and

(2) data rate control (DRC) information for a forward link on a Quadrature signal component of the reverse link.

10. The access terminal of claim 9, wherein the access terminal is configured to communicate with the radio network using an extension of a data-optimized communication standard.

11. The access terminal of claim 9, wherein:

the MIMO rank information consists of one bit; and

the MIMO spatial signature information consists of three bits.

12. The access terminal of claim 9, wherein:

the MIMO rank information comprises one bit;

the MIMO spatial signature information comprises three bits;

the DRC information comprises four bits; and

the MIMO rank information and the MIMO spatial signature information are transmitted on the In-Phase signal component as a four bit symbol.

13. The access terminal of claim 9, wherein:

the controller is further configured to execute the program code to cause the AT to estimate spatial physical channels between a plurality of transmit antennae of the BTS and a plurality of receive antennae of the AT, to obtain a plurality of estimates of the first forward link, the pluralities of transmit and receive antennae being configured for MIMO communication on the first forward link;

the step of determining MIMO rank information is performed based on the plurality of estimates of the first forward link; and

the step of determining MIMO spatial signature information is performed based on the plurality of estimates of the first forward link.

14. A machine-readable medium comprising instructions, the instructions, when executed by at least one processor of an access terminal (AT) for communicating with a base transceiver station (BTS) of a radio network configured to communicate with the access terminal using multiple-in multiple-out (MIMO) technique, cause the AT to perform operations comprising:

determining MIMO rank information of a first forward link between the BTS and the AT;

determining MIMO spatial signature information of the forward link; and

simultaneously transmitting

(1) the MIMO rank information and the MIMO spatial signature information on an In-Phase signal component of a reverse link between the BTS and the AT, and

(2) data rate control (DRC) information for a forward link on a Quadrature signal component of the reverse link.

15. A method of sending feedback from an access terminal (AT) to a base transceiver station (BTS) of a radio network configured to communicate with the access terminal using multiple-in multiple-out (MIMO) technique, the method comprising:

determining MIMO rank information of a first forward link between the BTS and the AT;

determining MIMO spatial signature information of the forward link; and

step for simultaneously transmitting to the BTS the MIMO rank information and the MIMO spatial signature on an In-Phase signal component of a reverse link between the BTS and the AT, and data rate control (DRC) information on a Quadrature component of the reverse link.

16. A method of receiving feedback from an access terminal (AT) sent to a base transceiver station (BTS) of a radio network configured to communicate with the access terminal using multiple-in multiple-out (MIMO) technique, the method comprising:

simultaneously receiving

(1) MIMO rank information of a forward link between the BTS and the AT and MIMO spatial signature information of the forward link on an In-Phase signal component of a reverse link between the BTS and the AT, and

(2) data rate control (DRC) information for the forward link on a Quadrature signal component of the reverse link; and

configuring the forward link in accordance with the MIMO rank information, MIMO spatial signature information, and the DRC information.

17. The method of claim 16, wherein the radio network is configured to provide services to the AT and to at least one non-MIMO capable access terminal.

18. The method of claim 16, wherein the radio network is configured to provide services to the AT and to at least one non-MIMO capable access terminal, the AT and the at least one other non-MIMO access terminal being in the same sector.

19. The method of claim 16, wherein the radio network is a data-optimized radio network.

20. The method of claim 16, wherein the radio network is configured to provide services to non-MIMO capable access terminals.

21. The method of claim 16, wherein:

the MIMO rank information consists of one bit; and

the MIMO spatial signature information consists of three bits.

22. The method of claim 16, wherein:

the MIMO rank information comprises one bit;

the MIMO spatial signature information comprises three bits; and

the DRC information comprises four bits.

23. A base transceiver station of a radio network configured to communicate with an access terminal (AT) using multiple-in multiple-out (MIMO) technique, the base transceiver station comprising:

a receiver configured to receive transmissions from the AT on a reverse link;

a transmitter configured to send transmissions to the AT on a forward link;

a memory storing program code; and

a controller coupled to the receiver, transmitter, and the memory, wherein the controller is configured to execute the program code to cause the base transceiver station to perform steps comprising;

receiving from the AT MIMO rank information of the forward link and MIMO spatial signature information of the forward link on an In-Phase signal component of the reverse link;

receiving data rate control (DRC) information for the forward link on a Quadrature signal component of the reverse link; and

configuring the base transceiver station to transmit to the AT on the forward link in accordance with the MIMO rank information, MIMO spatial signature information, and the DRC information.

24. The base transceiver station of claim 23, wherein the controller is further configured to execute the program code to cause the base transceiver station to provide services to at least one non-MIMO capable access terminal.

25. The base transceiver station of claim 23, wherein the controller is further configured to execute the program code to cause the base transceiver station to provide services to at least one non-MIMO capable access terminal, the at least one non-MIMO capable access terminal being in the same sector as the AT.

26. The base transceiver station of claim 23, wherein the radio network is a data-optimized radio network.

27. The base transceiver station of claim 23, wherein the radio network is configured to provide services to non-MIMO capable access terminals.

28. The base transceiver station of claim 23, wherein:

the MIMO rank information consists of one bit; and

the MIMO spatial signature information consists of three bits.

29. The base transceiver station of claim 23, wherein:

the MIMO rank information comprises one bit;

the MIMO spatial signature information comprises three bits; and

the DRC information comprises four bits.

30. A machine-readable medium comprising instructions, the instructions, when executed by at least one processor of a base transceiver station (BTS) configured for communicating with an access terminal (AT) using multiple-in multiple-out (MIMO) technique, cause the BTS to perform operations comprising:

simultaneously receiving

(1) MIMO rank information of a forward link between the BTS and the AT and MIMO spatial signature information of the forward link on an In-Phase signal component of a reverse link between the BTS and the AT, and

(2) data rate control (DRC) information for the forward link on a Quadrature signal component of the reverse link; and

configuring the forward link in accordance with the MIMO rank information, MIMO spatial signature information, and the DRC information.

31. A method of receiving feedback from an access terminal (AT) sent to a base transceiver station (BTS) of a radio network configured to communicate with the access terminal using multiple-in multiple-out (MIMO) technique, the method comprising:

step for simultaneously receiving

(1) MIMO rank information of a forward link between the BTS and the AT and MIMO spatial signature information of the forward link on an In-Phase signal component of a reverse link between the BTS and the AT, and

(2) data rate control (DRC) information for the forward link on a Quadrature signal component of the reverse link; and

configuring the forward link in accordance with the MIMO rank information, MIMO spatial signature information, and the DRC information.

32. A method of sending feedback from an access terminal (AT) to a base transceiver station (BTS) of a radio network configured to communicate with the access terminal using multiple-in multiple-out (MIMO) technique, the method comprising:

determining MIMO rank information of a first forward link between the BTS and the AT;

determining MIMO spatial signature information of the forward link; and

simultaneously transmitting

(1) the MIMO spatial signature information on an In-Phase signal component of a reverse link between the BTS and the AT, and

(2) the MIMO rank information and data rate control (DRC) information for a forward link on a Quadrature signal component of the reverse link, wherein the MIMO rank information is covered by a first codeword Walsh cover, the DRC information is covered by a second codeword Walsh cover, the second codeword Walsh cover being orthogonal to the first Walsh cover.

33. The method of claim 32, wherein the radio network is configured to provide services to the AT and to at least one non-MIMO capable access terminal.

34. The method of claim 32, wherein the radio network is configured to provide services to the AT and to at least one non-MIMO capable access terminal, the AT and the at least one other non-MIMO access terminal being in the same sector.

35. The method of claim 32, wherein the radio network is a data-optimized radio network.

36. The method of claim 32, wherein the radio network is configured to provide services to non-MIMO capable access terminals.

37. The method of claim 32, wherein:

the MIMO rank information consists of two bits; and

the MIMO spatial signature information consists of four bits.

38. The method of claim 32, wherein:

the MIMO rank information comprises two bits;

the MIMO spatial signature information comprises four bits; and

the DRC information comprises four bits.

39. The method of claim 32, further comprising:

estimating spatial physical channels between a plurality of transmit antennae of the BTS and a plurality of receive antennae of the AT, the pluralities of transmit and receive antennae being configured for MIMO communication on the first forward link, the step of estimating providing a plurality of estimates of the first forward link;

wherein;

the step of determining MIMO rank information is performed based on the plurality of estimates of the first forward link; and

the step of determining MIMO spatial signature information is performed based on the plurality of estimates of the first forward link.

40. An access terminal (AT) configured to communicate with a base transceiver station (BT) of a radio network using multiple-in multiple-out (MIMO) technique, the access terminal comprising:

a receiver configured to receive forward link transmissions from the BTS;

a transmitter configured to send reverse link transmissions to the BTS;

a memory storing program code; and

a controller coupled to the receiver, the transmitter, and the memory, wherein the controller is configured to execute the program code to cause the AT to perform steps comprising;

determining MIMO rank information of a first forward link between the BTS and the AT;

determining MIMO spatial signature information of the first forward link; and

simultaneously transmitting

(1) the MIMO spatial signature information on an In-Phase signal component of a reverse link between the BTS and the AT, and

(2) the MIMO rank information and data rate control (DRC) information for a forward link on a Quadrature signal component of the reverse link, wherein the MIMO rank information is covered by a first codeword Walsh cover, the DRC information is covered by a second codeword Walsh cover, the second codeword Walsh cover being orthogonal to the first Walsh cover.

41. The access terminal of claim 40, wherein the access terminal is configured to communicate with the radio network using an extension of a data-optimized communication standard.

42. The access terminal of claim 40, wherein:

the MIMO rank information consists of two bits; and

the MIMO spatial signature information consists of four bits.

43. The access terminal of claim 40, wherein:

the MIMO rank information comprises two bits;

the MIMO spatial signature information comprises four bits; and

the DRC information comprises four bits.

44. The access terminal of claim 40, wherein:

the controller is further configured to execute the program code to cause the AT to estimate spatial physical channels between a plurality of transmit antennae of the BTS and a plurality of receive antennae of the AT, to obtain a plurality of estimates of the first forward link, the pluralities of transmit and receive antennae being configured for MIMO communication on the first forward link;

the step of determining MIMO rank information is performed based on the plurality of estimates of the first forward link; and

the step of determining MIMO spatial signature information is performed based on the plurality of estimates of the first forward link.

45. A machine-readable medium comprising instructions, the instructions, when executed by at least one processor of an access terminal (AT) for communicating with a base transceiver station (BTS) of a radio network configured to communicate with the AT using multiple-in multiple-out (MIMO) technique, cause the AT to perform operations comprising:

determining MIMO rank information of a first forward link between the BTS and the AT;

determining MIMO spatial signature information of the forward link; and

simultaneously transmitting

(1) the MIMO spatial signature information on an In-Phase signal component of a reverse link between the BTS and the AT, and

(2) the MIMO rank information and data rate control (DRC) information for a forward link on a Quadrature signal component of the reverse link, wherein the MIMO rank information is covered by a first codeword Walsh cover, the DRC information is covered by a second codeword Walsh cover, the second codeword Walsh cover being orthogonal to the first Walsh cover.

46. A method of sending feedback from an access terminal (AT) to a base transceiver station (BTS) of a radio network configured to communicate with the AT using multiple-in multiple-out (MIMO) technique, the method comprising:

determining MIMO rank information of a first forward link between the BTS and the AT;

determining MIMO spatial signature information of the forward link;

step for simultaneously transmitting to the BTS the MIMO spatial signature information on an In-Phase signal component of a reverse link between the BTS and the AT, and data rate control (DRC) information and the MIMO rank information on a Quadrature signal component of the reverse link, wherein the MIMO rank information is covered by a first codeword Walsh cover, the DRC information is covered by a second codeword Walsh cover, the second codeword Walsh cover being orthogonal to the first Walsh cover.

47. A method of processing feedback sent from an access terminal (AT) to a base transceiver station (BTS) of a radio network configured to communicate with the AT using multiple-in multiple-out (MIMO) technique, the method comprising:

simultaneously receiving

(1) MIMO rank information and data rate control (DRC) information of a forward link between the BTS and the AT on a Quadrature signal component of a reverse link between the BTS and the AT, and

(2) MIMO spatial signature information for the forward link on an In-Phase signal component of the reverse link; and

configuring the forward link in accordance with the MIMO rank information, MIMO spatial signature information, and the DRC information.

48. The method of claim 47, wherein the radio network is configured to provide services to the AT and to at least one non-MIMO capable access terminal.

49. The method of claim 47, wherein the radio network is configured to provide services to the AT and to at least one non-MIMO capable access terminal, the AT and the at least one other non-MIMO access terminal being in the same sector.

50. The method of claim 47, wherein the radio network is a data-optimized radio network.

51. The method of claim 47, wherein the radio network is configured to provide services to non-MIMO capable access terminals in accordance.

53. The method of claim 47, wherein:

the MIMO rank information comprises two bits;

the MIMO spatial signature information comprises four bits; and

the DRC information comprises four bits.

54. A base transceiver station of a radio network configured to communicate with an access terminal (AT) using multiple-in multiple-out (MIMO) technique, the base transceiver station comprising:

a receiver configured to receive transmissions from the AT on a reverse link;

a transmitter configured to send transmissions to the AT on a forward link;

a memory storing program code; and

a controller coupled to the receiver, the transmitter, and the memory, wherein the controller is configured to execute the program code to cause the base transceiver station to perform steps comprising;

simultaneously receiving

(1) MIMO rank information and data rate control (DRC) information of the forward link between the BTS and the AT on a Quadrature signal component of the reverse link between the BTS and the AT, and

(2) MIMO spatial signature information for the forward link on an In-Phase signal component of the reverse link; and

configuring the forward link in accordance with the MIMO rank information, MIMO spatial signature information, and the DRC information.

52. The method of claim 58, wherein:

the MIMO rank information consists of two bits; and

the MIMO spatial signature information consists of four bits.

55. The base transceiver station of claim 54, wherein the controller is further configured to execute the program code to cause the base transceiver station to provide services to at least one non-MIMO capable access terminal.

56. The base transceiver station of claim 54, wherein the controller is further configured to execute the program code to cause the base transceiver station to provide services to at least one non-MIMO capable access terminal, the at least one non-MIMO capable access terminal being in the same sector as the AT.

57. The base transceiver station of claim 54, wherein the radio network is a data-optimized radio network.

58. The base transceiver station of claim 54, wherein the radio network is configured to provide services to non-MIMO capable access terminals.

59. The base transceiver station of claim 54, wherein:

the MIMO rank information consists of two bits; and

the MIMO spatial signature information consists of four bits.

60. The base transceiver station of claim 54, wherein:

the MIMO rank information comprises two bits;

the MIMO spatial signature information comprises four bits; and

the DRC information comprises four bits.

61. A machine-readable medium comprising instructions, the instructions, when executed by at least one processor of a base transceiver station (BTS) configured for communicating with an access terminal (AT) using multiple-in multiple-out (MIMO) technique, cause the BTS to perform operations comprising:

simultaneously receiving

(1) MIMO rank information and data rate control (DRC) information of a forward link between the BTS and the AT on a Quadrature signal component of a reverse link between the BTS and the AT, and

(2) MIMO spatial signature information for the forward link on an In-Phase signal component of the reverse link; and

configuring the forward link in accordance with the MIMO rank information, MIMO spatial signature information, and the DRC information.

62. A method of receiving feedback sent from an access terminal (AT) to a base transceiver station (BTS) of a radio network configured to communicate with the access terminal using multiple-in multiple-out (MIMO) technique, the method comprising:

step for simultaneously receiving

(1) MIMO rank information and data rate control (DRC) information of a forward link between the BTS and the AT on a Quadrature signal component of a reverse link between the BTS and the AT, and

(2) MIMO spatial signature information for the forward link on an In-Phase signal component of the reverse link; and

configuring the forward link in accordance with the MIMO rank information, MIMO spatial signature information, and the DRC information.