Radio communication system, base station apparatus, mobile terminal apparatus, and interference measurement method

• US 9,356,754 B2
• Filed: 07/12/2013
• Issued: 05/31/2016
• Est. Priority Date: 09/11/2012
• Status: Expired due to Fees

• Current Assignee: NTT Docomo Incorporated (Nippon Telegraph and Telephone Corporation)
• Original Assignee: NTT Docomo Incorporated (Nippon Telegraph and Telephone Corporation)
• Inventors: Nagata, Satoshi, Kishiyama, Yoshihisa
• Primary Examiner(s): Tran, Phuc
• Assistant Examiner(s): HOM, SHICK C
• Application Number:
  US14/426,337
• Publication Number:
  US 20150229452A1
• Time in Patent Office: 1,054 Days
• Field of Search: None
• US Class Current: 1/1
• CPC Class Codes: H04L 27/2636 with FFT or DFT modulators, e.g. standard single-carrier frequency-division multiple access [SC-FDMA] transmitter or DFT spread orthogonal frequency division multiplexing [DFT-SOFDM]
• CPC Class Codes: H04L 5/0023 Time-frequency-space
• CPC Class Codes: H04L 5/0048 Allocation of pilot signals, i.e. of signals known to the receiver
• CPC Class Codes: H04L 5/0051 of dedicated pilots, i.e. pilots destined for a single user or terminal
• CPC Class Codes: H04L 5/0073 Allocation arrangements that take into account other cell interferences for intercell interference mitigation or co-ordination in orthogonal multiplex systems H04J11/005
• CPC Class Codes: H04W 24/10 Scheduling measurement reports ; Arrangements for measurement reports

Abstract

The present invention is designed to increase the number of CSI-RSs for interference measurements and improve the accuracy of interference measurements. The first reference signal is allocated to a reference signal resource defined for transmission of the first reference signal, and also a second reference signal for interference measurement is allocated, the allocation patterns of the first reference signal and the second reference signal are implicitly reported to the first mobile terminal to apparatus that supports both the first reference signal and the second reference signal, and, in the first mobile terminal apparatus, interference is measured using both the first reference signal and the second reference signal or using the second reference signal alone, based on the implicitly-reported allocation patterns.

Claims

1. A radio communication system comprising a plurality of base station apparatuses that transmit a first reference signal for channel state measurement, and a first mobile terminal apparatus and a second mobile terminal apparatus that each connects with one of the plurality of base station apparatuses, wherein:

each base station apparatus comprises a reference signal allocation section that allocates the first reference signal to a first resource element in a reference signal resource defined for transmission of the first reference signal and also allocates a second reference signal for interference measurement to a second resource element in the reference signal resource, and implicitly reports allocation patterns of the first reference signal and the second reference signal to the first mobile terminal apparatus that supports both the first reference signal and the second reference signal; and

each mobile terminal apparatus comprises an interference measurement section that measures interference using both the first reference signal and the second reference signal or using the second reference signal alone, based on the allocation patterns reported implicitly from the base station apparatus,

wherein the reference signal allocation section allocates, as the second reference signal, a reference signal for both channel state measurement and interference measurement to the second resource element, based on the allocation pattern of the first reference signal that the second mobile terminal apparatus supports, and

the first mobile terminal apparatus measures channel states and interference using the second reference signal.

2. A base station apparatus, to which a plurality of mobile terminal apparatuses connect, wherein the base station apparatus comprises a reference signal allocation section that allocates a first reference signal to a first resource element in a reference signal resource defined for transmission of the first reference signal and also allocates a second reference signal for interference measurement to a second resource element in the reference signal resource, and implicitly reports allocation patterns of the first reference signal and the second reference signal to a first mobile terminal apparatus that supports both the first reference signal and the second reference signal,

wherein the reference signal allocation section allocates, as the second reference signal, a reference signal for both channel state measurement and interference measurement to the second resource element, based on the allocation pattern of the first reference signal that the second mobile terminal apparatus supports, and

the first mobile terminal apparatus measures channel states and interference using the second reference signal.

3. A mobile terminal apparatus that connects with a base station apparatus, the mobile terminal apparatus comprising:

an interference measurement section that, based on an allocation pattern of a first reference signal for channel state measurement and an allocation pattern of a second reference signal for interference measurement, allocated to a reference signal resource defined for transmission of the first reference signal, the allocation patterns being reported implicitly from the base station apparatus, measures interference using both the first reference signal and the second reference signal or using the second reference signal alone,

wherein, as the second reference signal, a reference signal for both channel state measurement and interference measurement is allocated to a resource element in the reference signal resource, based on an allocation pattern of the first reference signal that another mobile terminal apparatus supports, and

the interference measurement section measures channel states and interference using the second reference signal.

4. An interference method comprising the steps of:

allocating a first reference signal to a first resource element in a reference signal resource defined for transmission of the first reference signal for channel state measurement and also allocating a second reference signal for interference measurement to a second resource element in the reference signal resource;

implicitly reporting allocation patterns of the first reference signal and the second reference signal to a first mobile terminal apparatus that supports both the first reference signal and the second reference signal; and

measuring interference using both the first reference signal and the second reference signal or using the second reference signal alone, in the first mobile terminal apparatus, based on the implicitly reported allocation patterns,

wherein, as the second reference signal, a reference signal for both channel state measurement and interference measurement is allocated to the second resource element, based on an allocation pattern of the first reference signal that a second mobile terminal apparatus supports, and

the first mobile terminal apparatus measures channel states and interference using the second reference signal.

5. A radio communication system comprising a plurality of base station apparatuses that transmit a first reference signal for channel state measurement, and a first mobile terminal apparatus and a second mobile terminal apparatus that each connects with one of the plurality of base station apparatuses, wherein:

each base station apparatus comprises a reference signal allocation section that allocates the first reference signal to a first resource element in a reference signal resource defined for transmission of the first reference signal and also allocates a second reference signal for interference measurement to a second resource element in the reference signal resource, and implicitly reports allocation patterns of the first reference signal and the second reference signal to the first mobile terminal apparatus that supports both the first reference signal and the second reference signal; and

each mobile terminal apparatus comprises an interference measurement section that measures interference using both the first reference signal and the second reference signal or using the second reference signal alone, based on the allocation patterns reported implicitly from the base station apparatus,

wherein the reference signal allocation section allocates as the second reference signal, a reference signal for dedicated use in interference measurement to the second resource element, based on the allocation pattern of the first reference signal which the second mobile terminal apparatus supports, and

the first mobile terminal apparatus measures interference using the first reference signal and the reference signal for dedicated use in interference measurement.

6. A base station apparatus, to which a plurality of mobile terminal apparatuses connect, wherein the base station apparatus comprises a reference signal allocation section that allocates a first reference signal to a first resource element in a reference signal resource defined for transmission of the first reference signal and also allocates a second reference signal for interference measurement to a second resource element in the reference signal resource, and implicitly reports allocation patterns of the first reference signal and the second reference signal to a first mobile terminal apparatus that supports both the first reference signal and the second reference signal,

wherein the reference signal allocation section allocates, as the second reference signal, a reference signal for dedicated use in interference measurement to the second resource element, based on the allocation pattern of the first reference signal which the second mobile terminal apparatus supports, and

the first mobile terminal apparatus measures interference using the first reference signal and the reference signal for dedicated use in interference measurement.

7. A mobile terminal apparatus that connects with a base station apparatus, the mobile terminal apparatus comprising:

an interference measurement section that, based on an allocation pattern of a first reference signal for channel state measurement and an allocation pattern of a second reference signal for interference measurement, allocated to a reference signal resource defined for transmission of the first reference signal, the allocation patterns being reported implicitly from the base station apparatus, the measures interference using both the first reference signal and the second reference signal or using the second reference signal alone,

wherein, as the second reference signal, a reference signal for dedicated use in interference measurement is allocated to a resource element in the reference signal resource, based on the allocation pattern of the first reference signal which another mobile terminal apparatus supports, and

the interference measurement section measures interference using the first reference signal and the reference signal for dedicated use in interference measurement.

8. An interference method comprising the steps of:

allocating a first reference signal to a first resource element in a reference signal resource defined for transmission of the first reference signal for channel state measurement and also allocating a second reference signal for interference measurement to a second resource element in the reference signal resource;

implicitly reporting allocation patterns of the first reference signal and the second reference signal to a first mobile terminal apparatus that supports both the first reference signal and the second reference signal; and

measuring interference using both the first reference signal and the second reference signal or using the second reference signal alone, in the first mobile terminal apparatus, based on the implicitly reported allocation patterns,

wherein, as the second reference signal, a reference signal, for dedicated use in interference measurement is allocated to the second resource element, based on the allocation pattern of the first reference signal which a second mobile terminal apparatus supports, and the first mobile terminal apparatus measures interference using the first reference signal and the reference signal for dedicated use in interference measurement.