INTERFERENCE SUPPRESSION DURING DEVICE-TO-DEVICE COMMUNICATIONS

• US 20120099540A1
• Filed: 01/21/2010
• Published: 04/26/2012
• Est. Priority Date: 01/23/2009
• Status: Active Grant

• Current Assignee: WSOU Investments, LLC (WSOU Holdings, LLC)
• Original Assignee: Nokia Corporation
• Inventors: Doppler, Klaus Franz, Ribeiro, Cássio Barboza, Hugl, Klaus, Janis, Pekka, Wijting, Carl Simon
• Granted Patent: US 8,780,830 B2
• Time in Patent Office: Days
• US Class Current: 370/329
• CPC Class Codes: H04J 11/0033 by pre-cancellation of known interference, e.g. using a matched filter, dirty paper coder or Thomlinson-Harashima precoder correlative coding in synchronous or start-stop systems H04L25/497
• CPC Class Codes: H04L 25/0242 using matrix methods
• CPC Class Codes: H04L 25/03343 Arrangements at the transmitter end

Abstract

A method is disclosed that includes selecting one or more terminals involved in a device-to-device communication to which interference caused by a transmission to one or more other terminals should be suppressed, and choosing a number of degrees of freedom from a predetermined number of degrees of freedom to be used to suppress interference towards the selected one or more terminals. The method also includes using the remaining degrees of freedom from the predetermined number to increase signal quality to the one or more other terminals and performing precoding based on the chosen number of degrees of freedom and the remaining degrees of freedom. The method further includes, using at least the performed precoding, transmitting information to the one or more other terminals. Apparatus and programs/program products are also disclosed.

Claims

1-24. -24. (canceled)

25. A method, comprising:

selecting at least one terminal involved in a device-to-device communication to which interference caused by a transmission to at least one other terminal should be suppressed;

choosing a number of degrees of freedom from a predetermined number of degrees of freedom to be used to suppress interference towards the selected at least one terminal;

using the remaining degrees of freedom from the predetermined number to increase signal quality to the at least one other terminal;

performing precoding based on the chosen number of degrees of freedom and the remaining degrees of freedom; and

using at least the performed precoding, transmitting information to the at least one other terminal.

26. The method as in claim 25, wherein performing precoding further comprises:

forming an interference cancellation portion of a transmission precoding matrix based on the chosen number of degrees of freedom; and

forming a beamforming portion of the transmission precoding matrix based on the remaining degrees of freedom.

27. The method as in claim 25:

further comprising receiving information from the at least one terminal, where the received information is descriptive of an equivalent channel observed by the at least one terminal in the device-to-device communication; and

using the received information when performing at least the using of the remaining degrees of freedom from the predetermined number to increase signal quality to the at least one other terminal.

28. The method as in claim 27, where receiving further comprises receiving information descriptive of the equivalent channel observed by both terminals involved in the device-to-device communication.

29. The method as in claim 27, where the received information further includes an access point to other interference plus noise ratio or a requested amount of interference suppression.

30. The method as in claim 26, where forming the beamforming portion of the transmission precoding matrix further comprises using information descriptive of a channel observed by the at least one other terminal when forming the beamforming portion of the transmission precoding matrix.

31. The method as in claim 30, where information descriptive of a channel observed by the at least one other terminal is obtained by at least one of explicitly requesting the information, periodically receiving the information, and determining the information assuming channel reciprocity.

32. The method as in claim 28, where the precoding is performed so as to reduce interference towards both terminals involved in the device-to-device communication.

33. The method as in claim 25, where the precoding is performed so as to reduce interference towards only one of the terminals involved in the device-to-device communication, where the one terminal is known to be receiving during the device-to-device communication.

34. The method as in claim 33, where the device-to-device communication shares at least some of the radio resources used in the transmission of the information to the at least one other terminal.

35. The method as in claim 34, where the transmission is part of a cellular downlink communication of an orthogonal frequency division multiple access system.

36. The method as in claim 35, performed by an access point of a cellular communication system, where the access point and each of the terminals are equipped with a plurality of antennas.

37. An apparatus comprising:

at least one processor; and

at least one memory including computer program code, the at least one memory and the computer program code configured to, with the at least one processor, cause the apparatus to perform at least the following;

selecting at least one terminal involved in a device-to-device communication to which interference caused by a transmission to at least one other terminal should be suppressed;

choosing a number of degrees of freedom from a predetermined number of degrees of freedom to be used to suppress interference towards the selected at least one terminal;

using the remaining degrees of freedom from the predetermined number to increase signal quality to the at least one other terminal;

performing precoding based on the chosen number of degrees of freedom and the remaining degrees of freedom; and

using at least the performed precoding, causing information to be transmitted to the at least one other terminal.

38. The apparatus as in claim 37, wherein performing precoding further comprises:

forming an interference cancellation portion of a transmission precoding matrix based on the chosen number of degrees of freedom; and

forming a beamforming portion of the transmission precoding matrix based on the remaining degrees of freedom.

39. The apparatus as in claim 37:

wherein the received information is descriptive of an equivalent channel observed by the at least one terminal in the device-to-device communication; and

using the received information when performing at least the using of the remaining degrees of freedom from the predetermined number to increase signal quality to the at least one other terminal.

40. The apparatus as in claim 38, where forming the beamforming portion of the transmission precoding matrix further comprises using information descriptive of a channel observed by the at least one other terminal when forming the beamforming portion of the transmission precoding matrix.

41. The apparatus as in claim 40, where information descriptive of a channel observed by the at least one other terminal is obtained by at least one of explicitly requesting the information, periodically receiving the information, and determining the information assuming channel reciprocity.

42. The apparatus as in claim 37, where the precoding is performed so as to reduce interference towards only one of the terminals involved in the device-to-device communication, where the one terminal is known to be receiving during the device-to-device communication.

43. The apparatus as in claim 42, where the device-to-device communication shares at least some of the radio resources used in the transmission of the information to the at least one other terminal.

44. The apparatus as in claim 43, where the transmission is part of a cellular downlink communication;

wherein the apparatus is an access point of a cellular communication system, and where the access point and each of the terminals are equipped with a plurality of antennas.

45. A computer program, comprising:

code for selecting at least one terminal involved in a device-to-device communication to which interference caused by a transmission to at least one other terminal should be suppressed;

code for choosing a number of degrees of freedom from a predetermined number of degrees of freedom to be used to suppress interference towards the selected at least one terminal;

code for using the remaining degrees of freedom from the predetermined number to increase signal quality to the at least one other terminal;

code for performing precoding based on the chosen number of degrees of freedom and the remaining degrees of freedom; and

code for, using at least the performed precoding, causing information to be transmitted to the at least one other terminal,

when the computer program is run on a processor.