METHOD AND APPARATUS FOR TRANSMITTING REFERENCE SIGNALS IN COMMUNICATION SYSTEMS

• US 20110038302A1
• Filed: 08/13/2010
• Published: 02/17/2011
• Est. Priority Date: 08/13/2009
• Status: Active Grant

• Current Assignee: Samsung Electronics Co. Ltd.
• Original Assignee: Samsung Electronics Co. Ltd.
• Inventors: PAPASAKELLARIOU, Aris, CHO, Joon-Young
• Granted Patent: US 8,406,215 B2
• Time in Patent Office: Days
• US Class Current: 370/315
• CPC Class Codes: H04L 2025/03808 Transmission of equaliser coefficients
• CPC Class Codes: H04L 5/0007 the frequencies being orthogonal, e.g. OFDM(A), DMT
• CPC Class Codes: H04L 5/0048 Allocation of pilot signals, i.e. of signals known to the receiver
• CPC Class Codes: H04W 72/23 in the downlink direction of a wireless link, i.e. towards a terminal

Abstract

Methods and apparatus are described for a Relay Node (RN) that is transparent to User Equipments to transmit, together with a base station (Node B), Reference Signals (RS) to UEs, to receive RS from UEs, to perform transmissions of Transport Blocks (TBs) to the Node B or to UEs and receptions of TBs from the Node B or from UEs, where the transmissions of TBs from the RN are for retransmissions associated with a Hybrid Automatic Repeat reQuest (HARQ) process for the same TBs, and enabling the Node B to obtain control information signaled from UEs while signaling from the RN interferers with that signaling of control information.

Claims

1. A method for transmitting Reference Signals (RS) that are scrambled with parts of a common scrambling sequence to User Equipments (UEs) by a Node B and a Relay Node (RN) in a communication system, the method comprising the steps of:

transmitting RS by the Node B in a first set of transmission instances; and

transmitting RS by the RN in a second set of transmission instances, wherein the first set and the second set do not have any common transmission instances.

2. The method of claim 1, wherein the second set of transmission instances is signaled to the RN by the Node B.

3. The method of claim 1, wherein the Node B transmits RS from a first number of antennas over a first set of Resource Elements (REs) and the RN transmits RS from a second number of antennas over a second set of REs, and wherein the first number of antennas is larger than the second number of antennas, and the first set of REs is the same as the second set of REs.

4. The method of claim 1, wherein the Node B transmits RS from a first number of antennas over a first set of Resource Elements (REs) and the RN transmits RS from a second number of antennas over a second set of REs, and wherein the first number of antennas is larger than the second number of antennas, and the RN does not transmit any signal in REs in the first set of REs that are not in the second set of REs.

5. The method of claim 1, wherein the Node B informs the UEs, either with broadcast signaling or with UE-specific signaling, whether it is allowed to perform joint processing of the RS from different transmission instances.

6. A method for transmitting Reference Signals (RS) that are scrambled with parts of a common scrambling sequence to User Equipments (UEs) by a Node B and a Relay Node (RN) in a communication system, the method comprising the steps of:

transmitting RS by the Node B in a first set of transmission instances; and

transmitting RS by the RN in a second set of transmission instances, wherein the second set is a subset of the first set.

7. The method of claim 6, wherein the second set of transmission instances is signaled to the RN by the Node B.

8. The method of claim 6, wherein the Node B transmits RS from a first number of antennas over a first set of Resource Elements (REs) and the RN transmits RS from a second number of antennas over a second set of REs, and wherein the first number of antennas is larger than the second number of antennas, and the first set of REs is the same as the second set of REs.

9. The method of claim 6, wherein the Node B transmits RS from a first number of antennas over a first set of Resource Elements (REs) and the RN transmits RS from a second number of antennas over a second set of REs, and wherein the first number of antennas is larger than the second number of antennas, and the RN does not transmit any signal in REs in the first set of REs that are not in the second set of REs.

10. The method of claim 6, wherein the Node B informs the UEs, either with broadcast signaling or with UE-specific signaling, whether joint processing of RS transmitted by the Node B in different transmission instances in the first set may be performed.

11. A method for receiving Reference Signals (RS) transmitted from a User Equipment (UE) in a communication system by a Node B and a Relay Node (RN), the method comprising the steps of

signaling by the Node B RS transmission parameters to the UE;

obtaining by the RN the RS transmission parameters; and

receiving by the RN and the Node B the RS transmitted from the UE.

12. The method of claim 11, wherein the RN obtains the RS transmission parameters either through separate signaling from the Node B or through the same signaling to the UE.

13. The method of claim 11, wherein the RN transmits to the Node B information obtained from the reception of the RS transmitted from the UE.

14. The method of claim 11, wherein the RN discontinues the transmission of a transport block (TB) to the Node B at a transmission symbol determined from the transmission symbol the UE transmits the RS and the time required for the RN to switch from transmitting the TB to receiving the RS.

15. A method for transmitting Reference Signals (RS) that are scrambled with parts of a common scrambling sequence to User Equipments (UEs) by a Relay Node (RN) in a communication system, the method comprising the steps of:

determining by the RN Resource Elements (REs) where the UE transmits control information; and

transmitting by the RN information that is already known to the Node B in the REs where the UE transmits control information.

16. The method of claim 15, wherein the information already known by the UE is predetermined in operation of the communication system.

17. The method of claim 15, wherein the RN transmits an (RS) that is orthogonal to the RS transmitted by the UE.

18. A method for transmitting same Transport Block (TB) to a User Equipment (UE) or a Node B by one of a Node B and a User Equipment (UE) and a Relay Node (RN) in a communication system, respectively, the method comprising the steps of:

transmitting by one of the Node B and the UE the TB for a first number of transmissions associated with a Hybrid Automatic Repeat reQuest (HARQ) process number; and

transmitting by the RN the TB for a second number of transmissions associated with the HARQ process number wherein the second number of transmissions is smaller than the first number of transmissions.

19. The method of claim 18, wherein the second number of transmissions is configured to the RN by the Node B or is a fixed number defined in operation of the communication system.

20. A method for performing retransmissions of a Transport Block (TB) by a Relay Node (RN), for a synchronous non-adaptive Hybrid Automatic Repeat reQuest (HARQ) process having a reference HARQ process number, to a first Node, where an initial transmission of the TB for the reference HARQ process number was performed by a second Node, the method comprising the steps of:

receiving by the RN an acknowledgement signal with negative value (NACK) that is transmitted from the first Node in response to TB reception for the reference HARQ process number; and

transmitting by the RN to the first Node the TB for the reference HARQ process number in response to the acknowledgement signal in accordance with the HARQ process.

21. The method of claim 20, wherein the first Node is either a Node B or a User Equipment (UE) and the second Node is either a UE or a Node B, respectively.

22. A method for performing retransmissions of a Transport Block (TB), for a synchronous non-adaptive Hybrid Automatic Repeat reQuest (HARQ) process having a reference HARQ process number, to a first Node, where an initial transmission of the TB for the reference HARQ process number was performed by a second Node, the method comprising the steps of

receiving by the RN a Scheduling Assignment (SA) that is transmitted from a Node B Iii and indicates transmission of the same TB through a New Data Indicator (NDI) Information Element (IE);

and

transmitting by the RN to the first Node the TB for the reference HARQ process number in response to the SA in accordance with the HARQ process.

23. The method of claim 22, wherein the SA contains transmission power control commands for adjusting the power of the transmission from the RN to the first Node.

24. The method of claim 22, wherein the RN also receives an acknowledgement signal with negative value (NACK) that is transmitted from the first Node in response to the TB reception for the reference HARQ process number.

25. The method of claim 22, wherein the first Node is either a Node B or a User Equipment (UE) and the second Node is either a UE or a Node B, respectively.

26. In a communication system, a method for a Relay Node (RN) to pertbrm retransmissions a Transport Block (TB), for an asynchronous adaptive Hybrid Automatic Repeat reQuest (HARQ) process having a reference HARQ process number, to a first Node, where an initial transmission of the TB for the reference HARQ process number was performed by a second Node, the method comprising the steps of:

receiving by the RN a Scheduling Assignment (SA) that is transmitted from a Node B and indicates transmission of the same TB through a New Data Indicator (NDI) Information Element (IE) and through a HARQ process number IE that indicates the reference HARQ process number; and

transmitting by the RN to the first Node the TB for the reference HARQ process number in response to the SA in accordance with the HARQ process.

27. The method of claim 26, wherein the SA contains transmission power control commands for adjusting the power of the transmission from the RN to the first Node.

28. The method of claim 26, wherein the RN also receives an acknowledgement signal with negative value (NACK) that is transmitted from the first Node in response to the TB reception for the reference HARQ process number.

29. The method of claim 26, wherein the first Node is either a Node B or a User Equipment (UE) and the second Node is either a UE or a Node B, respectively.

30. A method for transmitting a Transport Block (TB) by a Relay Node (RN) to a first Node for retransmissions associated with a reference Hybrid Automatic Repeat reQuest (HARQ) process number, where an initial transmission of the TB to the UE for the reference HARQ process number was performed by a second Node, the method comprising the steps of:

receiving by the RN a first Scheduling Assignment (SA) transmitted from a Node B in a first Transmission Time Interval (TTI);

receiving by the RN the initial transmission of the TB from the second Node for the reference HARQ process number in a second TTI;

receiving by the RN a second SA transmitted from the Node B in a third TTI that configures a transmission from the RN to the first Node for a retransmission of the TB for the reference HARQ process number;

transmitting from the Node B to a User Equipment (UE) a third SA in a fourth TTI that configures a transmission from the second Node to the first Node in a fifth TTI for the retransmission of the TB for the reference HARQ process number; and

transmitting by the RN to the first Node in the fifth TTI the retransmission of the TB for the reference HARQ process number in accordance with the second SA.

31. The method of claim 30, wherein the format of the first SA and the format of the third SA are different than the format of the second SA.

32. The method of claim 31, wherein the first SA and the third SA are for a single UE and the second SA is for multiple UEs.

33. The method of claim 30, wherein all SAs include a scrambled Cyclic Redundancy Check (CRC) and the CRCs in the first SA and the third SA are scrambled with a first sequence and the CRC in the second SA is scrambled with a second sequence.

34. The method of claim 33, wherein the first sequence is a function of the UE identity and the second sequence is a function of the UE identity and the RN identity.

35. The method of claim 30, wherein the second SA contains transmission power control commands for adjusting the power of the transmission from the RN to the UE.

36. The method of claim 30, wherein the second SA indicates the third TTI.

37. The method of claim 30, wherein the first Node is either a Node B or a User Equipment (UE) and the second Node is either a UE or a Node B, respectively.

38. The method of claim 30, wherein the first TTI is the same as the second TTI and the fourth TTI is the same as the filth TTI.

39. An apparatus for transmitting Reference Signals (RS) that are scrambled with parts of a common scrambling sequence to User Equipments (UEs) by a Node B and a Relay Node (RN) in a communication system, the apparatus comprising:

a first transmitter for transmitting RS by the Node B in a first set of transmission instances; and

a second transmitter for transmitting RS by the RN in a second set of transmission instances, wherein the first set and the second set do not have any common transmission instances.

40. The apparatus of claim 39, wherein the second set of transmission instances is signaled to the RN by the Node B.

41. The apparatus of claim 39, wherein the Node B transmits RS from a first number of antennas over a first set of Resource Elements (REs) and the RN transmits RS from a second number of antennas over a second set of REs, and wherein the first number of antennas is larger than the second number of antennas, and the first set of REs is the same as the second set of REs.

42. The apparatus of claim 39, wherein the Node B transmits RS from a first number of antennas over a first set of Resource Elements (REs) and the RN transmits RS from a second number of antennas over a second set of REs, and wherein the first number of antennas is larger than the second number of antennas, and the RN does not transmit any signal in REs in the first set of REs that are not in the second set of REs.

43. The apparatus of claim 39, wherein the Node B informs the UEs, either with broadcast signaling or with UE-specific signaling, whether it is allowed to perform joint processing of the RS from different transmission instances.