METHOD AND ARRANGEMENT FOR MANAGING A REFERENCE SIGNAL FOR UPLINK CHANNEL ESTIMATION IN A COMMUNICATIONS SYSTEM

• US 20100165894A1
• Filed: 03/24/2006
• Published: 07/01/2010
• Est. Priority Date: 03/24/2006
• Status: Active Grant

• Current Assignee: Telefonaktiebolaget LM Ericsson
• Original Assignee: Telefonaktiebolaget LM Ericsson
• Inventors: Skillermark, Per, Furuskar, Anders
• Granted Patent: US 8,121,106 B2
• Time in Patent Office: Days
• US Class Current: 370/281
• CPC Class Codes: H04B 2201/709709 Methods of preventing interference
• CPC Class Codes: H04L 5/0042 intra-user or intra-terminal allocation
• CPC Class Codes: H04L 5/0046 Determination of how many bits are transmitted on different sub-channels
• CPC Class Codes: H04L 5/0094 Indication of how sub-channels of the path are allocated
• CPC Class Codes: H04L 5/143 for modulated signals H04L5/1469 takes precedence
• CPC Class Codes: H04L 5/1484 operating bytewise

Abstract

An object of the present invention is to provide a mechanism of measuring a reference signal that is less over head consuming and less time consuming. The object is achieved by a method for managing uplink channel estimation in a base station. The base station is comprised in a radio access network using Frequency Division Duplex (FDD). The base station is associated with a first cell of a number of cells within the radio access network. The base station is adapted to connect at least one mobile terminal, being situated in the first cell, to a network infrastructure. The method comprises the step of transmitting a redirected reference signal on an uplink band to the mobile terminal. The redirected reference signal is intended for uplink channel estimation.

Claims

1. Method for managing uplink channel estimation in a base station, which base station is comprised in a radio access network using Frequency Division Duplex (FDD), the base station being associated with a first cell of a number of cells within the radio access network, the base station being adapted to connect at least one mobile terminal being situated in the first cell, to a network infrastructure, the method comprising the steps of:

transmitting a redirected reference signal in an uplink band to the mobile terminal, said redirected reference signal being intended for uplink channel estimation.

2. Method according to claim 1, wherein the step of transmitting the redirected reference signal is performed time multiplexed.

3. Method according to claim 1, wherein the step of transmitting the redirected reference signal is performed such that it covers the entire uplink frequency band.

4. Method according to claim 1, wherein the redirected reference signal is surrounded by a guard period.

5. Method according to claim 4, wherein the guard period is 60-70 μ

s.

6. Method according to claim 1, wherein the step of transmitting the redirected reference signal is performed by frequency multiplexing.

7. Method according to claim 1, wherein the frequency of transmitting the redirected reference signal is adapted in accordance with a channel coherence time.

8. Method according to claim 7, wherein the channel coherence time is estimated as Tc=c/(f*v).

9. Method according to claim 1, wherein the redirected reference signal is transmitted every 5-10 ms frame, preferably in every 10 ms frame.

10. Method according to claim 1, wherein multiple redirected reference signals are transmitted per time frame.

11. Method according to claim 1, wherein the radio access network uses WINNER technology, wherein the redirected reference signal is transmitted in the first part of a super-frame.

12. Method according to claim 1, wherein the method comprises the further step of:

receiving a report from the mobile terminal that received the redirected reference signal, the report comprising the uplink channel quality, estimated by the terminal by knowing the origin redirected reference signal, estimating the received redirected reference signal and comparing the known redirected reference signal with the received redirected reference signal.

13. Method according to claim 12, comprising the further step of:

performing uplink quality based frequency domain scheduling based on the uplink channel quality comprised in the report.

14. Method according to claim 13, wherein the uplink quality based frequency domain scheduling is performed by input the received channel quality to the scheduling algorithm for uplink quality based frequency domain scheduling in the time and/or in the frequency domain.

15. Method according to claim 1, wherein the method comprises the further steps of:

receiving a regular uplink reference signal from the terminal, and estimating the uplink channel quality, based on the received regular reference signal.

16. Method according to claim 15, wherein the channel quality, based on the received regular reference signal, is used as a further input to a scheduling algorithm for uplink quality based frequency domain scheduling in at least one or both of the time domain and the frequency domain.

17. Method according to claim 13, the method comprising the further steps of:

transmitting an uplink control message on a downlink channel to the mobile terminal based on the performed uplink quality based frequency domain scheduling.

18. Computer program product for managing uplink channel estimation in a base station, comprising computer program code for causing a processing means within a computer placed in the base station to control an execution of the steps of claim 1, when said code is loaded into the computer.

19. Arrangement in a base station being comprised in a radio access network using Frequency Division Duplex, the base station being associated with a first cell of a number of cells within the radio access network, the base station being adapted to connect at least one mobile terminal being situated in the first cell, to a network infrastructure, the base station arrangement comprises a transmitter for transmitting a redirected reference signal on an uplink band to the mobile terminal, said redirected reference signal being intended for uplink channel estimation.

20. Base station arrangement according to claim 19, wherein the transmitter is adapted to transmit the redirected reference signal time multiplexed.

21. Base station arrangement according to claim 19, wherein the transmitter further is adapted to transmit the redirected reference signal such that it covers the entire uplink frequency band.

22. Base station arrangement according to claim 19, wherein the transmitter further is adapted to transmit the redirected reference signal surrounded by a guard period.

23. Base station arrangement according to claim 22, wherein the guard period is 60-70 μ

s.

24. Base station arrangement according to claim 19, wherein the transmitter is adapted to transmit the redirected reference signal frequency multiplexed.

25. Base station arrangement according to claim 19, wherein the transmitter is arranged to transmit the redirected reference signal with a frequency that is adapted in accordance with the channel coherence time.

26. Base station arrangement according to claim 25, wherein the channel coherence time is estimated as Tc=c/.

27. Base station arrangement according to claim 19, wherein the transmitter is arranged to transmit the redirected reference signal in every 5-10 ms frame, preferably in every 10 ms frame.

28. Base station arrangement according to claim 19, wherein the transmitter is arranged to transmit multiple redirected reference signals per time frame.

29. Base station arrangement according to claim 19, wherein the radio access network uses WINNER technology, wherein the transmitter is arranged to transmit the redirected reference signal in the first part of a super-frame.

30. Base station arrangement according to claim 19, wherein the base station arrangement further comprises a receiver arranged for receiving a report from the mobile terminal that has received the redirected reference signal, the report comprising the uplink channel quality, estimated by the mobile terminal by knowing the origin redirected reference signal, estimating the received redirected reference signal and comparing the known redirected reference signal with the received redirected reference signal.

31. Base station arrangement according to claim 30, comprising means for performing uplink quality based frequency domain scheduling based on the uplink channel quality comprised in the report.

32. Base station arrangement according to claim 31, wherein the uplink quality based frequency domain scheduling means is arranged to input the received channel quality to the scheduling algorithm for uplink quality based frequency domain scheduling in the time and/or in the frequency domain.

33. Base station arrangement according to claim 19, wherein the receiver further is arranged to receiving a regular uplink reference signal from the mobile terminal, and wherein the base station arrangement comprises an estimation unit for estimating the uplink channel quality, based on the received regular reference signal.

34. Base station arrangement according to claim 32, wherein the uplink quality based frequency domain scheduling means further is arranged to input channel quality, based on the received regular reference signal, to the scheduling algorithm for uplink quality based frequency domain scheduling in the time and/or in the frequency domain.

35. Base station arrangement according to claim 31, wherein the transmitter further is arranged to transmit an uplink control message on an downlink channel to the mobile terminal based on the performed uplink quality based frequency domain scheduling.

36. Method for managing uplink channel estimation in a mobile terminal, the mobile terminal being comprised in a radio access network using Frequency Division Duplex, the radio access network comprising a number of cells, the mobile terminal being situated in a first cell of said number of cells, the mobile terminal is connectable to a network infrastructure via a base station associated with the first cell, the method comprising the steps of:

receiving a redirected reference signal on an uplink band from the base station, said redirected reference signal being intended for uplink channel estimation.

37. Method according to claim 36, wherein the mobile terminal knows the origin redirected reference signal transmitted by the base station, the estimation of the uplink channel quality is performed by the further method steps of:

estimating the received redirected reference signal; and

comparing the known redirected reference signal with the estimated received redirected reference signal.

38. Method according to claim 36, wherein the step of comparing is based on the amplitude and/or phase of the origin redirected reference signal and received redirected reference signal.

39. Method according to claim 36, comprising the further step of:

determining adaptive modulation and/or coding scheme and/or which power to use, and/or antenna weights, based on the estimated uplink channel quality.

40. Method according to claim 36, comprising the further step of:

transmitting a report to the base station, the report comprising the estimated uplink channel quality.

41. Computer program product for managing uplink channel estimation in a mobile terminal, comprising computer program code for causing a processing means within a computer placed in the mobile terminal to control an execution of the steps of claim 36, when said code is loaded into the computer.

42. Arrangement in a mobile terminal being comprised in a radio access network using Frequency Division Duplex, the radio access network comprising a number of cells, the mobile terminal being situated in a first cell of said number of cells, the mobile terminal is connectable to a network infrastructure via a base station associated with the first cell, the mobile station arrangement comprises a receiver for receiving a redirected reference signal, on the uplink band, from the base station, said redirected reference signal being intended for uplink channel estimation.

43. Mobile terminal arrangement according to claim 42, wherein the mobile terminal knows the origin redirected reference signal transmitted by the base station, the mobile terminal arrangement comprising an estimation unit for estimation of the uplink channel quality, the estimation unit being arranged to estimate the received redirected reference signal, and further being arranged to compare the known redirected reference signal with the estimated received redirected reference signal.

44. Mobile terminal arrangement according to claim 42, wherein the estimation unit further is arranged to make the comparing based on the amplitude and/or phase of the origin redirected reference signal and received redirected reference signal.

45. Mobile terminal arrangement according to claim 42, further comprises a determination unit means for determining adaptive modulation and/or coding scheme and/or which power to use, and/or antenna weights, based on the estimated uplink channel quality.

46. Mobile terminal arrangement according to claim 42, further comprising a transmitter arranged to transmit a report to the base station, the report comprising the estimated uplink channel quality.