Method and Apparatus for Establishing a Time-Frequency Reference Signal Pattern Configuration in a Carrier Extension or Carrier Segment

• US 20140219237A1
• Filed: 06/07/2011
• Published: 08/07/2014
• Est. Priority Date: 06/07/2011
• Status: Active Application

• Current Assignee: Avago Technologies General IP PTE Limited (Broadcom, Inc.)
• Original Assignee: Broadcom Corporation (Broadcom, Inc.)
• Inventors: Charbit, Gilles, Zeng, Erlin, Wang, Haiming, Gao, Chunyan
• Application Number:
  US14/123,770
• Publication Number:
  US 20140219237A1
• Time in Patent Office: Days
• US Class Current: 370/330
• CPC Class Codes: H04L 25/0222 Estimation of channel variability, e.g. coherence bandwidth, coherence time, fading frequency
• CPC Class Codes: H04L 25/0224 using sounding signals
• CPC Class Codes: H04L 5/0005 Time-frequency
• CPC Class Codes: H04L 5/001 the frequencies being arranged in component carriers
• CPC Class Codes: H04L 5/0048 Allocation of pilot signals, i.e. of signals known to the receiver
• CPC Class Codes: H04L 5/005 of common pilots, i.e. pilots destined for multiple users or terminals
• CPC Class Codes: H04L 5/0092 Indication of how the channel is divided
• CPC Class Codes: H04W 24/10 Scheduling measurement reports ; Arrangements for measurement reports
• CPC Class Codes: H04W 72/044 based on the type of the allocated resource

Abstract

Methods, apparatus and computer program products are provided for establishing a time-frequency reference signal pattern configuration in a carrier extension or a carrier segment, such as for cell-specific reference signals (CRS) and/or demodulation reference signals (DM RS). One method includes receiving information regarding a time-frequency reference signal pattern configuration in a carrier extension or carrier segment. The time-frequency reference signal pattern configuration defines a subframe to include a reference signal based upon a time density parameter and defines a resource element to be utilized within the subframe based upon a frequency density parameter. This method also includes receiving reference signals pursuant to the time-frequency reference signal pattern configuration such that reference signals have a coherence time T_coh with at least one subframe including a reference signal in the CE or CS per T_coh and a coherence bandwidth B_coh with at least one resource element containing a reference signal per B_coh.

Claims

1. A method comprising:

receiving information regarding a time-frequency reference signal pattern configuration in a carrier extension (CE) or a carrier segment (CS), wherein the time-frequency reference signal pattern configuration defines a subframe to include a reference signal based upon a time density parameter N_TD and defines a resource element to be utilized within the subframe based upon a frequency density parameter N_FD; and

receiving reference signals in accordance with the time-frequency reference signal pattern configuration such that the reference signals have a coherence time T_coh with at least one subframe including a reference signal in the CE or CS per T_coh and a coherence bandwidth B_coh with at least one resource element containing a reference signal per B_coh.

2. A method according to claim 1 wherein the reference signal comprises a cell-specific reference signal (CRS) or a demodulation reference signal (DM RS).

3. A method according to claim 1, further comprising:

estimating a coherence time and a coherence bandwidth; and

causing estimates of the coherence time and the coherence bandwidth to be reported to facilitate updating of the time-frequency reference signal pattern configuration.

4. A method according to claim 1, further comprising causing a channel quality indicator (CQI) or a precoding matrix indicator (PMI) to be reported to facilitate updating of the time-frequency reference signal pattern configuration.

5. A computer program product comprising at least one computer-readable storage medium having computer-executable program code instructions stored therein, the computer-executable program code instructions comprising program code instructions, when executed, for performing the method of claim 1.

6. An apparatus comprising:

at least one processor; and

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

receiving information regarding a time-frequency reference signal pattern configuration in a carrier extension (CE) or a carrier segment (CS), wherein the time-frequency reference signal pattern configuration defines a subframe to include a reference signal based upon a time density parameter N_TD and defines a resource element to be utilized within the subframe based upon a frequency density parameter N_FD; and

receiving reference signals in accordance with the time-frequency reference signal pattern configuration such that the reference signals have a coherence time T_coh with at least one subframe including a reference signal in the CE or CS per T_coh and a coherence bandwidth B_coh with at least one resource element containing a reference signal per B_coh.

7. An apparatus according to claim 6 wherein the reference signal comprises a cell-specific reference signal (CRS) or a demodulation reference signal (DM RS).

8. An apparatus according to claim 6, wherein the at least one memory and the computer program code are further configured to, with the at least one processor, cause the apparatus to:

estimate a coherence time and a coherence bandwidth; and

cause estimates of the coherence time and the coherence bandwidth to be reported to facilitate updating of the time-frequency reference signal pattern configuration.

9. An apparatus according to claim 6, wherein the at least one memory and the computer program code are further configured to, with the at least one processor, cause the apparatus to cause a channel quality indicator (CQI) or a precoding matrix indicator (PMI) to be reported to facilitate updating of the time-frequency reference signal pattern configuration.

10. An apparatus according to claim 6, wherein the at least one processor;

and the at least one memory are embodied in a mobile terminal.

12. An apparatus according to claim 6, wherein the at least one memory and the computer program code are configured to, with the at least one processor, cause the apparatus to provide for communications by providing for communications in a Long Term Evolution (LTE) system.

11. (canceled)

13-17. -17. (canceled)

18. An apparatus comprising:

at least one processor; and

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

defining a time-frequency reference signal pattern configuration in a carrier extension (CE) or a carrier segment (CS) to have density parameters including a time density parameter N_TD that defines a subframe to include a reference signal and a frequency density parameter N_FD that defines a resource element to be utilized within the subframe; and

in an instance in which a neighboring base station has a time-frequency reference signal pattern configuration with a respective density parameter that is the same, coordinating the reference signal patterns by offsetting the reference signal pattern.

19. An apparatus according to claim 18 wherein the at least one memory and the computer program code are further configured to, with the at least one processor, cause the apparatus to, in an instance in which the neighboring base stations have time-frequency reference signal pattern configurations with the respective density pattern being different, coordinate the reference signal patterns by shifting the reference signal pattern.

20. An apparatus according to claim 18, wherein the reference signal comprises a cell-specific reference signal (CRS) or a demodulation reference signal (DM RS).

21. An apparatus according to claim 18, wherein the at least one memory and the computer program code are further configured to, with the at least one processor, cause the apparatus to define the time-frequency reference signal pattern to define a blank subframe and utilize the blank subframe for inter-cell interference coordination (ICIC) or non-cellular interference measurements.

22. An apparatus according to claim 18, wherein the at least one processor;

and the at least one memory are embodied in a base station.

29. The apparatus according to claim 18, wherein the at least one memory and the computer program code are configured to, with the at least one processor, cause the apparatus at least to further perform:

receiving a report of a channel quality indicator (CQI) or a precoding matrix indicator (PMI) for a subband S_i for each of a plurality of channel state information (CSI) measurement time intervals T_Δ

;

determining a number n of consecutive intervals T_Δ

over which the report of the CQI or the PMI remains consistent; and

determining a subband CSI measurement report periodicity for the subband S_i based upon a product of the number n and the interval T_Δ

.

30. An apparatus according to claim 29 wherein the product of the number n and the interval T_Δ

is less than a coherence time T_coh.

31. An apparatus according to claim 29, wherein the at least one memory and the computer program code are further configured to, with the at least one processor, cause the apparatus to cause the subband CSI measurement report periodicity to be provided to a mobile terminal.

32. An apparatus according to claim 29, wherein the at least one memory and the computer program code are further configured to, with the at least one processor, cause the apparatus to determine a coherence bandwidth B_coh and set a CSI subband size B_w for subband S_i equal to B_coh.

23-28. -28. (canceled)

33-34. -34. (canceled)