(19)
(11)EP 3 541 109 B1

(12)EUROPEAN PATENT SPECIFICATION

(45)Mention of the grant of the patent:
29.07.2020 Bulletin 2020/31

(21)Application number: 19173247.8

(22)Date of filing:  29.10.2010
(51)International Patent Classification (IPC): 
H04W 16/28(2009.01)
H04B 7/024(2017.01)
H04J 13/00(2011.01)
H04B 17/354(2015.01)
H04J 11/00(2006.01)
H04L 5/00(2006.01)
H04L 1/20(2006.01)
H04L 1/00(2006.01)

(54)

WIRELESS COMMUNICATION APPARATUS AND REFERENCE SIGNAL GENERATING METHOD

DRAHTLOSKOMMUNIKATIONSVORRICHTUNG UND REFERENZSIGNALERZEUGUNGSVERFAHREN

APPAREIL DE COMMUNICATION SANS FIL ET PROCÉDÉ DE GÉNÉRATION DE SIGNAL DE RÉFÉRENCE


(84)Designated Contracting States:
AL AT BE BG CH CY CZ DE DK EE ES FI FR GB GR HR HU IE IS IT LI LT LU LV MC MK MT NL NO PL PT RO RS SE SI SK SM TR

(30)Priority: 30.10.2009 JP 2009250432

(43)Date of publication of application:
18.09.2019 Bulletin 2019/38

(62)Application number of the earlier application in accordance with Art. 76 EPC:
18155351.2 / 3337217
10826358.3 / 2496005

(73)Proprietor: Sun Patent Trust
New York, NY 10022 (US)

(72)Inventors:
  • IWAI, Takashi
    Osaka-shi Osaka 540-6207 (JP)
  • IMAMURA, Daichi
    Osaka-shi Osaka 540-6207 (JP)
  • NISHIO, Akihiko
    Osaka-shi Osaka 540-6207 (JP)
  • OGAWA, Yoshihiko
    Osaka-shi Osaka 540-6207 (JP)
  • FUKUOKA, Masaru
    Osaka-shi Osaka 540-6207 (JP)

(74)Representative: Grünecker Patent- und Rechtsanwälte PartG mbB 
Leopoldstraße 4
80802 München
80802 München (DE)


(56)References cited: : 
WO-A1-2008/111317
WO-A1-2009/084224
WO-A1-2008/155907
  
  • NOKIA SIEMENS NETWORKS ET AL: "Uplink DM RS performance evaluation from CoMP viewpoint", 3GPP DRAFT; R1-093307, 3RD GENERATION PARTNERSHIP PROJECT (3GPP), MOBILE COMPETENCE CENTRE ; 650, ROUTE DES LUCIOLES ; F-06921 SOPHIA-ANTIPOLIS CEDEX ; FRANCE, no. Shenzhen, China; 20090818, 18 August 2009 (2009-08-18), XP050351631,
  • ALCATEL-LUCENT SHANGHAI BELL ET AL: "Uplink coordinated multi-point reception with distributed inter- cell interference suppression for LTE-A", 3GPP DRAFT; R1-093366 UL COMP RECEPTION WITH DISTRIB INTERF SUPPRESSION, 3RD GENERATION PARTNERSHIP PROJECT (3GPP), MOBILE COMPETENCE CENTRE ; 650, ROUTE DES LUCIOLES ; F-06921 SOPHIA-ANTIPOLIS CEDEX ; FRANCE, vol. RAN WG1, no. Shenzhen, China; 20090824 - 20090828, 19 August 2009 (2009-08-19), XP050597656,
  • "3rd Generation Partnership Project; Technical Specification Group Radio Access Network; Evolved Universal Terrestrial Radio Access (E-UTRA); Physical Channels and Modulation (Release 8)", 3GPP STANDARD; 3GPP TS 36.211, 3RD GENERATION PARTNERSHIP PROJECT (3GPP), MOBILE COMPETENCE CENTRE ; 650, ROUTE DES LUCIOLES ; F-06921 SOPHIA-ANTIPOLIS CEDEX ; FRANCE, no. V8.8.0, 1 September 2009 (2009-09-01), pages 1-83, XP050377540,
  
Note: Within nine months from the publication of the mention of the grant of the European patent, any person may give notice to the European Patent Office of opposition to the European patent granted. Notice of opposition shall be filed in a written reasoned statement. It shall not be deemed to have been filed until the opposition fee has been paid. (Art. 99(1) European Patent Convention).


Description

Technical Field



[0001] The present invention relates to a radio communication apparatus and reference signal generation method that generates a reference signal used to estimate channel quality.

Background Art



[0002] In an uplink of LTE-Advanced, which is improved 3GPP LTE (3rd Generation Partnership Project Long Term Evolution), a study is underway to introduce UL CoMP (Coordinated multiple point transmission and reception). CoMP is a technique aiming to improve mainly throughput of a terminal located in a cell edge, by performing transmission and reception with a terminal between a plurality of cells (base stations) in a coordinated manner.

[0003] In the case of UL CoMP, by receiving and combining a transmission signal from one terminal at a plurality of cells (base stations), reception quality is improved. At this time, within a group (hereinafter, referred to as "CoMP set") of cells performing transmission and reception in a coordinate manner, terminal scheduling is also performed in a coordinated manner among a plurality of cells forming a CoMP set, in order to reduce influence of inter-cell interference.

[0004] On the other hand, LTE uses an SRS (Sounding Reference Signal) of uplink. Here, "Sounding" is referred to estimating channel quality, and an SRS is transmitted by time-multiplexing a specific symbol with data in order to mainly estimate CQI (Channel Quality Indicator) of uplink data channel.

[0005] LTE uses a ZC (Zadoff-Chu) sequence as an SRS. The characteristic of a ZC sequence includes that CS-ZC (Cyclic Shifted-ZC) sequences generated by cyclically shifting a ZC sequence of any ZC sequence number with a longer time length than the maximum propagation delay time are ideally orthogonal (inter-code interference is zero). However, ZC sequences having different ZC sequence numbers are not orthogonal, and cross-correlation (inter-code interference) occurs at a certain level of "1/ZC sequence length". According to the above characteristic, LTE provides a ZC sequence group defining ZC sequence numbers for each transmission bandwidth available in cells, and one ZC sequence group is assigned to each cell (e.g. see Non-Patent Document 1). 30 of these ZC sequence groups are defined, and to reduce inter-cell interference, different ZC sequence groups are assigned to adjacent cells.

[0006] In order to improve reception quality in the above UL CoMP, accurate estimation of channel quality using an SRS is necessary. Therefore, at first, it is necessary to select a ZC sequence number for an SRS transmitted by a terminal to which UL CoMP is applied, that is, the terminal (hereinafter, referred to as "CoMP terminal") where transmission signals are received and combined at a plurality of cells. As this selection method, two methods (selection method 1 and selection method 2) can be considered.

[0007] Selection method 1 is a method selecting, for an SRS of a CoMP terminal, a ZC sequence assigned to a cell (hereinafter, referred to as "serving cell") that transmits control information such as scheduling information to the terminal. That is, in a serving cell of a CoMP terminal, a terminal (hereinafter, referred to as "Non-CoMP terminal") to which UL CoMP is not applied uses the same ZC sequence for an SRS as a CoMP terminal.

[0008] Selection method 2 is a method selecting, for an SRS of a CoMP terminal, a ZC sequence of a ZC sequence number different from that of a ZC sequence to be used by a Non-CoMP terminal inside a CoMP set. That is, a ZC sequence belonging to a ZC sequence group (a ZC sequence group not used inside a CoMP set, that is, a ZC sequence group used outside a CoMP set) different from ZC sequence groups assigned to cells inside a CoMP set, is used in an SRS of a CoMP terminal.
NPL 2 discusses limitations from the UL CoMP viewpoint by providing performance comparision between different reference signal designs.

[0009] NPL 3 describes an approach for UL CoMP reception by considering signal cell processing for inter-cell co-channel interference suppression among the users in neighboring cells with the aid of the relative information of UE in neighbor cells.

[0010] NPL 4 relates to the physical channels for evolved UTRA.

[0011] PL1 describes a sequence allocating method that, while maintaining the number of Zadoff-Chu sequences to compose a sequence group, is configured to make it possible to reduce correlations between different sequential groups and between same sequential groups.

[0012] PL2 describes a radio transmission device and a radio transmission method which can reduce a processing amount or a memory amount while maintaining the randomizing effect of other cell interference.

[0013] PL3 describes a wireless communication terminal apparatus wherein the occurrences of inter-sequence interferences between a reference signal preceding a sequence hopping and a reference signal following the sequence hopping can be reduced so as to improve the randomizing effect achieved by the sequence hopping.

Citation List


Non-Patent Literature



[0014] 

NPL1
3GPP TS36.211 V8.7.0.5.5.1 Generation of the reference signal sequence, "Physical Channels and Modulation (Release 8)"

NPL2
R1-093307 "Uplink DM RS performance evaluation from CoMP viewpoint" Nokia Siemens Networks, Nokia

NPL3
R1-093366 "Uplink coordinated multi-point reception with distributed inter-cell interference suppression for LTE-A" Alcatel-Lucent Shanghai Bell, Alcatel-Lucent

NPL4
3GPP TS 36.211 V8.8.0 Evolved Universal Terrestrial Radio (E-UTRA) "Physical Channels and Modulation" (Release 8)


Patent Literature



[0015] 

PL1
WO2008/155907 A1

PL2
WO2008/111317 A1

PL3
WO2009/084224 A1


Summary of Invention


Technical Problem



[0016] However, the above selection method 1 has a problem that strong interference occurs inside a CoMP set. This problem will be explained below in detail.

[0017] As shown in FIG.1, when a CoMP terminal transmits one transmission signal to a plurality of cells having different distances, each cell receives the signal at different reception timing, thereby making transmission timing control at a terminal complicated. Therefore, in a certain cell, wrong transmission timing control causes reception timing of an SRS transmitted by a CoMP terminal to expand a predetermined time range, which breaks the orthogonality between CS-ZC sequences using the same ZC sequence numbers.

[0018] When reception timing of an SRS which a CoMP terminal transmits is delayed by expanding a predetermined time length, a large correlation value of reception SRS of a CoMP terminal expands a predetermined CS (Cyclic Shift) detection window and enters a CS detection window of a Non-CoMP terminal, as shown in correlation output (delay profile) of an SRS in FIG.2.

[0019] As a result, in a CS detection window of a CoMP terminal, it is not possible to detect reception SRS of a CoMP terminal. A reception SRS correlation value of a CoMP terminal entering a CS detection window of a Non-CoMP terminal becomes a significant interference component, so that in a CS detection window of a Non-CoMP terminal, it is difficult to distinguish between an interference component and a signal component, which deteriorates the accuracy of CQI estimation.

[0020] Further, once reception timing of an SRS that a CoMP terminal transmits is delayed, an SRS of a Non-CoMP terminal is always interfered strongly by CS-ZC sequences having broken orthogonality in a CoMP terminal, until transmission timing control is updated. Therefore, in this cell, the accuracy of CQI estimation is deteriorated, causing adequate scheduling not to perform properly, and thus system throughput is deteriorated.

[0021] In the above selection method 2, there is a problem that interference increases outside CoMP set. This problem will be explained below in detail.

[0022] When a CoMP terminal uses ZC sequence numbers to be used outside a CoMP set, inter-cell interference between a Non-CoMP terminal (a conventional LTE terminal) outside a CoMP set and a CoMP terminal increases, thereby deteriorating the accuracy of CQI estimation. Since the number of ZC sequence numbers (a ZC sequence group) which a terminal can use is limited, when ZC sequence numbers outside a comp set are used, the distance to a Non-CoMP terminal in a cell using the same ZC sequence number becomes short, thereby increasing inter-cell interference (cross-correlation). FIG.3 shows this state.

[0023] FIG.3 shows ZC sequence numbers used in cells, when ZC sequence numbers available in a system are 1 to 19 for ease of explanation. In FIG.3, one cell is represented in a hexagon shape and ZC sequence numbers are assigned to make cells using the same ZC sequence number to be as distant as possible from each other, in order to reduce inter-cell interference. As shown in FIG.3, it is assumed that cells where ZC sequence numbers 1, 2, and 3 are assigned form one CoMP set and a CoMP terminal inside a CoMP set uses ZC sequence number 16 not used in the CoMP set as a ZC sequence for an SRS. In this case, since the distance to the cell using the ZC sequence number 16 outside a CoMP set becomes shorter, and the distance attenuation of an interference wave becomes smaller, thereby increasing inter-cell interference.

[0024] It is therefore an object of the present invention to provide a radio communication apparatus and reference signal generation method that reduce inter-cell interference inside and outside a CoMP set.

Solution to Problem



[0025] This object is achieved by the present invention as claimed in the independent claims. Advantageous and preferred embodiments of the present invention are defined by the dependent claims. The invention relates to a base station apparatus and corresponding method as defined in the claims. References to embodiments not falling under the scope of the claims are to be understood as examples useful for understanding the invention.

[0026] In an example useful for understanding the present invention,
the radio communication apparatus employs a configuration having: a CoMP mode setting section that sets one of a CoMP terminal to which CoMP (Coordinated Multiple Point transmission and reception) transmission and reception for performing transmission and reception among a plurality of cells in a coordinated manner, is applied, and a Non-CoMP terminal to which the CoMP transmission and reception is not applied; a hopping pattern calculation section that includes a plurality of different hopping patterns for hopping a ZC (Zadoff-Chu) sequence number to be used for a reference signal, hops the ZC sequence number by a hopping pattern according to the CoMP terminal or the Non-CoMP terminal set by the CoMP mode setting section, and calculates the ZC sequence number; and a ZC sequence generation section that generates a ZC sequence using the calculated ZC sequence number.

[0027] In another example,
the reference signal generation method has steps in which it sets one of a CoMP terminal to which CoMP (Coordinated Multiple Point transmission and reception) transmission and reception for performing transmission and reception among a plurality of cells in a coordinated manner, is applied, and a Non-CoMP terminal to which the CoMP transmission and reception is not applied; includes a plurality of different hopping patterns for hopping a ZC (Zadoff-Chu) sequence number to be used as a reference signal, hops the ZC sequence number by a hopping pattern according to the set CoMP terminal or the set Non-CoMP terminal, and calculates the ZC sequence number; and generates a ZC sequence to be used for the reference signal, using the calculated ZC sequence number.

Advantageous Effects of Invention



[0028] According to the present invention, it is possible to reduce inter-cell interference inside and outside a CoMP set.

Brief Description of Drawings



[0029] 

FIG.1 shows that a transmission signal from a CoMP terminal is received at a plurality of cells having different distances;

FIG.2 shows correlation output of SRSs which a CoMP terminal and a Non-CoMP terminal transmit;

FIG.3 shows ZC sequence numbers to be used in cells;

FIG.4 is a block diagram showing a configuration of a radio communication terminal apparatus according to Embodiment 1 of the present invention;

FIG.5 is a block diagram showing a configuration of a base station according to Embodiment 1 of the present invention;

FIG.6 shows a hopping pattern of ZC sequence numbers according to Embodiment 1 of the present invention;

FIG.7 shows correlation output of SRSs transmitted by a CoMP terminal and a Non-CoMP terminal according to Embodiment 1 of the present invention;

FIG.8 shows the state able to maintain distances between cells using the same ZC sequence numbers as designed;

FIG.9 shows other hopping pattern of ZC sequence numbers according to Embodiment 1 of the present invention;

FIG.10 shows a hopping pattern of ZC sequence numbers according to Embodiment 2 of the present invention; and

FIG.11 shows a hopping pattern of ZC sequence numbers according to Embodiment 3 of the present invention.


Description of Embodiments



[0030] Embodiments of the present invention will be described in detail with reference to the accompanying drawings.

(Embodiment 1)



[0031] FIG.4 is a block diagram showing the configuration of a radio communication terminal apparatus (hereinafter, referred to as "terminal") 10 according to Embodiment 1 of the present invention. Next, a configuration of terminal 100 will be explained using FIG.4.

[0032] CoMP mode setting section 101 sets to hopping pattern calculation section 104 a CoMP mode designated in advance by a radio communication base station apparatus (hereinafter, referred to as "base station"), that is, whether terminal 100 performs CoMP transmission and reception (CoMP terminal), or terminal 100 does not perform CoMP transmission and reception (Non-CoMP terminal).

[0033] ZC sequence number inside CoMP set setting section 102 sets ZC sequence numbers for an SRS assigned to a plurality of cells inside a CoMP set, and outputs the result to hopping pattern calculation section 104.

[0034] ZC sequence number in system setting section 103 sets all ZC sequence numbers for an SRS available in a system, and outputs the result to hopping pattern calculation section 104.

[0035] Hopping pattern calculation section 104 calculates a hopping pattern of ZC sequence numbers according to a CoMP mode set by CoMP mode setting section 101, and outputs ZC sequence numbers to be used at transmission timing to ZC sequence generation section 105, based on the calculated hopping pattern. Specifically, when terminal 100 is a CoMP terminal, a ZC sequence number which is reported from ZC sequence number inside CoMP set setting section 102 and used inside a CoMP set is hopped by the calculated hopping pattern, and therefore a ZC sequence number to be used at transmission timing is calculated. Meanwhile, when terminal 100 is a Non-CoMP terminal, all ZC sequence numbers reported from ZC sequence number in system setting section 103 and available in the system are hopped by the calculated hopping pattern, a ZC sequence number to be used at transmission timing is calculated. Also, hopping pattern calculation section 104 will be described later in detail.

[0036] ZC sequence generation section 105 generates a ZC sequence to be used as an SRS, by using a ZC sequence number output from hopping pattern calculation section 104, and outputs the result to mapping section 106.

[0037] Mapping section 106 maps a ZC sequence for an SRS output from ZC sequence generation section 105, to a transmission band of terminal 100 designated in advance by a base station, and outputs the mapped ZC sequence to IFFT (Inverse Fast Fourier Transform) section 107.

[0038] IFFT section 107 performs IFFT processing on the ZC sequence output from mapping section 106, and outputs the ZC sequence subjected to IFFT processing to CP (Cyclic Prefix) addition section 108.

[0039] CP addition section 108 adds the same signal as the end part of the signal output from IFFT section 107, to the beginning of the signal as a CP, and outputs the signal to RF (radio frequency) transmission section 109.

[0040] RF transmission section 109 performs transmission processing such as D/A conversion, up-conversion and amplification on the signal output from CP addition section 108, and transmits the signal subjected to transmission processing as an SRS via antenna 110.

[0041] FIG.5 is a block diagram showing the configuration of base station 200 according to Embodiment 1 of the present invention. The configuration of base station 200 is described below using FIG.5.

[0042] RF reception section 202 applies reception processing such as down-conversion and A/D conversion to a signal received via antenna 201, and outputs the signal subjected to reception processing is applied to CP removing section 203.

[0043] CP removing section 203 removes the CP added to the top of a reception signal output from RF reception section 202, and outputs the result to FFT (Fast Fourier Transform) section 204.

[0044] FFT section 204 performs FFT processing on an SRS of time domain output from CP removing section 203, transforms the result to frequency domain signals, and outputs the transformed frequency domain to demapping section 205.

[0045] Demapping section 205 extracts an SRS corresponding to a transmission band of a desired terminal from the frequency domain SRS that is output from FFT section 204, and outputs the extracted SRS to division section 211.

[0046] CoMP mode setting section 206 sets to hopping pattern calculation section 209, a CoMP mode designated by a control section (not shown) and the like, that is, whether terminal 100 performs CoMP transmission and reception (CoMP terminal), or terminal 100 does not perform CoMP transmission and reception (Non-CoMP terminal).

[0047] ZC sequence number inside CoMP set setting section 207 sets ZC sequence numbers for an SRS assigned to a plurality of cells inside a CoMP set, and outputs the result to hopping pattern calculation section 209.

[0048] ZC sequence number in system setting section 208 sets all ZC sequence numbers for SRS available in the system, and outputs the result to hopping pattern calculation section 209.

[0049] Hopping pattern calculation section 209 calculates a hopping pattern of ZC sequence numbers according to a CoMP mode set by CoMP mode setting section 206, and outputs ZC sequence numbers to be used at reception timing of a signal transmitted from terminal 100, to ZC sequence generation section 210, based on the calculated hopping pattern. Specifically, when terminal 100 is a CoMP terminal, a ZC sequence number which is reported from ZC sequence number inside CoMP set setting section 207 and to be used inside a CoMP set is hopped by the calculated hopping pattern, and a ZC sequence number to be used at transmission timing is therefore calculated. Meanwhile, when terminal 100 is a Non-CoMP terminal, all ZC sequence numbers which are reported from ZC sequence number in system setting section 208 and available in the system are hopped by the calculated hopping pattern, a ZC sequence number to be used at transmission timing is calculated.

[0050] CoMP mode setting section 206, ZC sequence number inside CoMP set setting section 207, ZC sequence number in system setting section 208, and hopping pattern calculation section 209 correspond to and have the same function as CoMP mode setting section 101, ZC sequence number inside CoMP set setting section 102, ZC sequence number in system setting section 103, and hopping pattern calculation section 104 in terminal 100 shown in FIG.4 respectively.

[0051] As described above, hopping pattern calculation section 209 calculates a hopping pattern according to whether terminal 100 transmitting an SRS is a CoMP terminal or a Non-CoMP terminal, and specifies a ZC sequence number at SRS transmission timing of terminal 100.

[0052] ZC sequence generation section 210 generates a ZC sequence for an SRS transmitted by terminal 100, using a ZC sequence number output from hopping pattern calculation section 209, and outputs the result to division section 211.

[0053] Division section 211 divides the SRS output from demapping section 205 by the ZC sequence for an SRS output from ZC sequence generation section 210, and outputs the divided result to IFFT section 212.

[0054] IFFT section 212 performs IFFT processing on the divided result output from division section 211, and outputs the signal subjected to IFFT processing (equivalent to a delay profile) to masking processing section 213.

[0055] Mask processing section 213 extracts the interval in which the correlation value of the desired CS-ZC sequence is present, that is, extracts the correlation value in a CS detection window, by performing mask processing on the SRS output from IFFT section 212, and outputs the extracted correlation value to DFT (Discrete Fourier Transform) section 214.

[0056] DFT section 214 performs DFT processing to the correlation values output from mask processing section 213 and outputs the correlation values subjected to DFT processing, to CQI estimation section 215. Here, the signal which is subjected to DFT processing and output from DFT section 214 represents the frequency response of the channel.

[0057] CQI estimation section 215 estimates (channel quality estimation) SINR for every predetermined bandwidth, based on a signal representing the frequency response output from DFT section 214, and outputs a CQI estimation value corresponding to the estimated SINR.

[0058] Next, the operation of hopping pattern calculation section 104 of terminal 100 shown in FIG.4 will be described. Hopping pattern calculation section 209 of base station 200 performs the same operation as hopping pattern calculation section 104, and a detailed description therefore will be omitted.

[0059] According to whether terminal 100 is a CoMP terminal or a Non-CoMP terminal, hopping pattern calculation section 104 switches a hopping pattern of ZC sequence numbers for an SRS, and specifies a ZC sequence number for an SRS, to be used at transmission timing.

[0060] First, when terminal 100 is a Non-CoMP terminal, hopping pattern calculation section 104 calculates ZC sequence number uN(t) for an SRS of a Non-CoMP terminal as shown in equation 1, using the hopping function "hopping ( )" which is defined in the system in advance.



[0061] Here, N represents a cell number, t represents a transmission subframe number, and uN_init represents an initial value of a ZC sequence number for an SRS in cell N. By each subframe, this hopping function changes numbers among all ZC sequence numbers available in the system. However, ZC sequence number uN(t) for an SRS of a Non-CoMP terminal may be fixed without changing by one subframe.

[0062] Next, when terminal 100 is a CoMP terminal, hopping pattern calculation section 104 hops a ZC sequence number which a Non-CoMP terminal uses inside a CoMP set. For example, when a CoMP set is formed with three cells of cell 1, cell 2, and cell 3, hopping pattern calculation section 104 calculates ZC sequence number uCoMP(t) for an SRS of a CoMP terminal as shown in equation 2.



[0063] In equation 2, (t)mod(3) represents the number of the remainder calculated by dividing transmission subframe number t by cell number 3. Here, it is assumed that transmission subframe number t is changed in order of t#0→ t#1→ t#2→ t#3→ t#4. In this case, ZC sequence number uCoMP(t) for an SRS of a CoMP terminal to be used at transmission timing of each transmission subframe is changed as u1(0)→u2(1)→u3(2)→u1(3)→u2(4) according to equation 2. The change is made among ZC sequence numbers to be used in cells #1, 2, and 3 inside a CoMP set.

[0064] FIG.6 shows this state. In FIG.6, ZC sequence number 1 (ZC#1) is assigned to cell 1 inside a CoMP set, ZC sequence number 2 (ZC#2) is assigned to cell 2, and ZC sequence number 3 (ZC#3) is assigned to cell 3, respectively. The ZC sequence number for an SRS of a CoMP terminal, the number to be used by transmission subframe number t at transmission timing of t#0, becomes ZC#1, and a CoMP terminal and a Non-CoMP terminal which is in cell 1 multiplex the ZC sequence of ZC#1 by different CSZC sequences.

[0065] Next, the ZC sequence number for an SRS of a CoMP terminal, the number to be used by transmission subframe number t at transmission timing of t#1, hops from ZC#1 to ZC#2, a CoMP terminal and a Non-CoMP terminal which is in cell 2 multiplex the ZC sequence of ZC#2 by different CSZC sequences.

[0066] Next, the ZC sequence number for an SRS of a CoMP terminal, the number to be used by transmission subframe number t at transmission timing of t#2, hops from ZC#2 to ZC#3, a CoMP terminal and a Non-CoMP terminal which is in cell 3 multiplex the ZC sequence of ZC#2 by different CSZC sequences.

[0067] The ZC sequence number for an SRS of a CoMP terminal, the number to be used by transmission subframe number t at a transmission timing of t#3, hops from ZC#3 to ZC#1, and thereby returns to the case where transmission subframe number t is t#0.

[0068] By hopping ZC sequence numbers used by a CoMP terminal within the range of the ZC sequence to be used inside a CoMP set, it is possible to prevent strong interference occurring when a CoMP terminal and a Non-CoMP terminal use the same ZC sequence from continuing in one cell. This is contributed by hopping ZC sequence numbers that a CoMP terminal uses and ZC sequence numbers that a Non-CoMP terminal using different hopping patterns, and by making a switching interval of ZC sequences according to hopping shorter than an updating interval of transmission timing control.

[0069] When a CoMP terminal and a Non-CoMP terminal use different ZC sequence numbers, interference components become cross-correlation at a certain level, and it is therefore possible to reduce deterioration of the accuracy of CQI estimation even if the receiving timing is delayed, as shown in FIG.7. Also, a certain level of interference components makes it possible to perform compensation calculation at a receiver and thereby to prevent deterioration of the accuracy of CQI estimation.

[0070] As shown in FIG.8, a CoMP terminal uses a ZC sequence inside a CoMP set, thereby not providing inter-cell interference to a terminal outside a CoMP set. That is, the distance between cells using the same ZC sequence number can be maintained as designed, so that it is possible to prevent increasing of inter-cell interference between a CoMP terminal and a terminal outside a CoMP set.

[0071] Thus, according to Embodiment 1, by hopping a ZC sequence number used by a CoMP terminal within the range of the ZC sequence to be used inside a CoMP set, it is possible to prevent strong interference occurring when a CoMP terminal and a Non-CoMP terminal use the same ZC sequence, from continuing in one cell. Also, a CoMP terminal uses a ZC sequence inside a CoMP set, it is possible to prevent increasing of inter-cell interference between a CoMP terminal and a terminal outside a CoMP set.

[0072] Although the present embodiment has described a case where a ZC sequence assigned to a cell inside a CoMP set is fixed, a ZC sequence number assigned to a cell inside a CoMP set may be hopped, as shown in FIG.9. However, in this case, it is necessary to make a hopping pattern of a ZC sequence number in a specific cell, different from a hopping pattern of a ZC sequence number used by a CoMP terminal.

[0073] By defining in advance a hopping pattern of a ZC sequence number for an SRS, the number used by a CoMP terminal, it is possible to reduce the signaling amount from a base station to a terminal. That is, an initial value (=uN_init) of each cell inside a CoMP set, and a hopping pattern of each cell (for example, in ascending cell number order) need to be reported to a terminal only once, and therefore signaling for each SRS transmission is not necessary.

[0074] Hopping patterns of ZC sequence numbers used by a CoMP terminal and a Non-CoMP terminal may not have regularity.

(Embodiment 2)



[0075] Since the configuration of a terminal according to Embodiment 2 of the present invention is similar to the configuration of Embodiment 1 shown in FIG.4 and is different only in function of hopping pattern calculation section 104, so that hopping pattern calculation section 104 will be described using FIG.4. Also, since the configuration of a base station to Embodiment 2 of the present invention is similar to the configuration of Embodiment 1 shown in FIG.5, and is different only in function of hopping pattern calculation section 209, which is the same as hopping pattern calculation section 104 of a terminal, a detailed description will be therefore omitted.

[0076] According to whether terminal 100 is a CoMP terminal or a Non-CoMP terminal, hopping pattern calculation section 104 switches hopping patterns of ZC sequence numbers for an SRS, and specifies the ZC sequence number for an SRS which should be used at transmission timing.

[0077] When terminal 100 is a Non-CoMP terminal, as in Embodiment 1, hopping pattern calculation section 104 calculates ZC sequence number uN(t) for an SRS of a Non-CoMP terminal by equation 1.

[0078] Meanwhile, when terminal 100 is a CoMP terminal, hopping pattern calculation section 104 hops a ZC sequence number to be used by a Non-CoMP terminal outside a CoMP set. For example, when a CoMP set is formed with three cells of cell 1, cell 2, and cell 3, hopping pattern calculation section 104 calculates ZC sequence number uCoMP(t) for an SRS of a CoMP terminal as shown in equation 3.



[0079] In equation 3, 27 represents the number obtained by subtracting 3 which is the number of cells of a CoMP set, from 30 which is the number of all ZC sequence numbers available in the whole system, that is the number of ZC sequence number to be used outside a CoMP set. Here, transmission subframe number t is assumed to be changed in order of t#0 → t#1 → t#2 → t#3 → t#4. In this case, ZC sequence number uCoMP(t) for an SRS of a CoMP terminal, the number to be used at transmission timing of each transmission subframe becomes u4(0)→u5(1)→u6(2)→u7(3)→u8(4), according to equation 3. The change is made among ZC sequence numbers used outside a CoMP set.

[0080] FIG.10 shows this state. In FIG.10, at transmission timing when transmission subframe number t is t#0, a ZC sequence number for an SRS of a CoMP terminal uses ZC#4, ZC sequence number 1 (ZC#1) is assigned to cell 1 inside a CoMP set, ZC sequence number 2 (ZC#2) is assigned to cell 2, and ZC sequence number 3 (ZC#3) is assigned to cell 3, respectively.

[0081] Next, at transmission timing when transmission subframe number t changes from t#0 to t#1, a ZC sequence number for an SRS of a CoMP terminal hops from ZC#4 to ZC#7, cell 1 hops from ZC#1 to ZC#4, cell 2 hops from ZC#2 to ZC#5, and cell 3 hops from ZC#3 to ZC#6.

[0082] Next, at transmission timing when transmission subframe number t changes from t#1 to t#2, a ZC sequence number for an SRS of a CoMP terminal hops from ZC#7 to ZC#10, cell 1 hops from ZC#4 to ZC#7, cell 2 hops from ZC#5 to ZC#8, and cell 3 hops from ZC#6 to ZC#9.

[0083] Next, at transmission timing when transmission subframe number t changes from t#2 to t#3, a ZC sequence number for an SRS of a CoMP terminal hops from ZC#10 to ZC#13, cell 1 hops from ZC#7 to ZC#10, cell 2 hops from ZC#8 to ZC#11, and cell 3 hops from ZC#9 to ZC#12.

[0084] Thus, according to Embodiment 2, by hopping a ZC sequence number used by a CoMP terminal within the range of the ZC sequence to be used outside a CoMP set, a ZC sequence number for an SRS of a CoMP terminal and a ZC sequence number for an SRS of a Non-CoMP terminal always differ inside a CoMP set. Therefore, it is possible to prevent strong interference occurring in the case where a CoMP terminal and a Non-CoMP terminal use the same ZC sequence.

[0085] Also, a Non-CoMP terminal inside a CoMP set hops a ZC sequence number used by a CoMP terminal with a different pattern, and it is therefore possible to randomize interference between a Non-CoMP terminal outside a CoMP set, the Non-CoMP terminal using the same ZC sequence number as that inside a CoMP set and a Non-CoMP terminal inside a CoMP set, and thereby to reduce deterioration of the accuracy of CQI estimation caused by the interference.

[0086] Although the present embodiment has described a case where hopping patterns of ZC sequence numbers used by a CoMP terminal and a Non-CoMP terminal has regularity, these hopping patterns need not to have regularity.

(Embodiment 3)



[0087] Embodiment 3 of the present invention will describe a case where a certain cell includes a plurality of CoMP terminals and different CoMP sets include a plurality of CoMP terminals. In this case, by providing a hopping pattern of a ZC sequence number for an SRS to each CoMP terminal, a ZC sequence number for an SRS to each CoMP terminal in a cell differs. Therefore, it is not possible to make SRS used by a plurality of CoMP terminals orthogonal by CDM (code domain), and therefore the accuracy of CQI estimation deteriorates. By multiplexing SRSs for a plurality of CoMP terminals using TDM (time domain) or FDM (frequency domain), SRS orthogonality can prevent deterioration of the accuracy of CQI estimation, but a time for SRS transmission in a cell and overhead of frequency resource increase.

[0088] Hereinafter, in the case where a plurality of CoMP terminals are included in different CoMP sets, a method will be described to prevent deterioration of the accuracy of CQI estimation and reduce a time for SRS transmission in a cell and overhead of frequency resource.

[0089] The configuration of a terminal according to Embodiment 3 of the present invention is similar to the configuration shown in FIG.4 of Embodiment 1 and differs only in function of ZC sequence number inside CoMP set setting section 102, and therefore the different functions thereof will be explained using FIG.4. Also, since the configuration of a base station to Embodiment 3 of the present invention is similar to the configuration of Embodiment 1 shown in FIG.5, and differs only in function of ZC sequence number inside CoMP set setting section 207, which is the same as ZC sequence number inside CoMP set setting section 207 of a terminal, a detailed description will be therefore omitted.

[0090] ZC sequence number inside CoMP set setting section 102 sets a ZC sequence number for an SRS, that is, the number to be used by all cells forming a CoMP set where a plurality of CoMP terminals present in a cell belong, and outputs the setting result to hopping pattern calculation section 104.

[0091] For example, it is assumed that two CoMP terminals 1 and 2 are present in a cell, the CoMP set where CoMP terminal 1 belongs is formed by cells 1 and 2, and the CoMP set where CoMP terminal 2 belongs is formed by cells 2 and 3. That is, it is assumed that CoMP sets differs in the configuration between CoMP terminals 1 and 2. In this case, ZC sequence number inside CoMP set setting section 102 sets all cells forming CoMP sets where a plurality of CoMP terminals belongs respectively, that is, a combining CoMP set formed by cells 1 to 3. Then, ZC sequence number inside CoMP set setting section 102 outputs ZC sequence numbers for SRSs of cells 1 to 3 to hopping pattern calculation section 104.

[0092] FIG.11 shows this state. Although FIG.11 has the same hopping pattern as shown in FIG.9, FIG.11 differs from FIG.9 in that two CoMP terminals 1 and 2 use the same ZC sequence. Also, Fig.11 differs from FIG.9 in that a CoMP set where CoMP terminal 1 belongs is formed by cells 1 and 2, a CoMP set where CoMP terminal 2 belongs is formed by cells 2 and 3, and ZC sequence numbers are hopped among all cells forming CoMP sets where a plurality of CoMP terminals belong.

[0093] Thus, according to Embodiment 3, in the case where a plurality of CoMP terminals present in a certain cell are included in different CoMP sets respectively, a ZC sequence number to be used by a CoMP terminal is hopped, within the range of the ZC sequence to be used by all cells forming CoMP sets where a plurality of CoMP terminals belong. Consequently, it is possible to make ZC sequence numbers used by a plurality of CoMP terminals present in a certain cell to be the same, and therefore CDM (code axis) can orthogonalize SRSs used by a plurality of CoMP terminals. Therefore, it is possible to prevent the accuracy of CQI estimation from deterioration. Also, there is no need to multiplex SRSs of a plurality of CoMP terminals in order to be orthogonal by TDM or FDM, so that it is possible to reduce a time for SRS transmission and overhead of frequency resource.

[0094] A CoMP set in the above embodiments can be referred to as "CoMP cooperating set." Also, a CoMP set may be a cell group (=CoMP measurement set) to which a terminal reports channel quality information for CoMP transmission and reception.

[0095] Although the above embodiments have described as an example an SRS transmitted by a terminal to which UL CoMP is applied, the present invention is not limited to this. For example, an SRS may be used for CSI (Channel State Information) feedback to perform adaptive control (resource assignment, MCS control, update of a precoding vector) of downlink CoMP in TDD (Time Division Duplex). Thus, the essential requirement is that one terminal transmits an SRS to a plurality of cells at the same time.

[0096] A ZC sequence number in the above embodiments may be replaced as "ZC sequence group number."

[0097] Although the above embodiments have described a case where a ZC sequence number of a CoMP terminal and a ZC sequence number of a Non-CoMP terminal are hopped at the same switching period, it is equally possible to hop such ZC sequences numbers at different switching periods. For example, it is assumed that a ZC sequence switching period of a Non-CoMP terminal is T1[ms] and a ZC sequence switching period of a CoMP terminal is T2[ms] (please note that T2[ms]>T1[ms], including that T2 is infinite (that is, no switching)).

[0098] By this means, inside a CoMP set, it is possible to prevent strong interference occurring when a CoMP terminal and a Non-CoMP terminal use the same ZC sequence from continuing in one cell. Here, when a switching period of a ZC sequence of one terminal is infinite, only a ZC sequence of the other terminal is switched, and therefore interference with a Non-CoMP terminal outside a CoMP set using the same ZC sequence number can be randomized.

[0099] Although the above embodiments have described an example where the present invention is implemented with hardware, the present invention can be implemented with software.

[0100] Furthermore, each function block employed in the description of each of the aforementioned embodiments may typically be implemented as an LSI constituted by an integrated circuit. These may be individual chips or partially or totally contained on a single chip. "LSI" is adopted here but this may also be referred to as "IC," "system LSI," "super LSI," or "ultra LSI" depending on differing extents of integration.

[0101] Further, the method of circuit integration is not limited to LSI's, and implementation using dedicated circuitry or general purpose processors is also possible. After LSI manufacture, utilization of an FPGA (Field Programmable Gate Array) or a reconfigurable processor where connections and settings of circuit cells in an LSI can be regenerated is also possible.

[0102] Further, if integrated circuit technology comes out to replace LSI's as a result of the advancement of semiconductor technology or a derivative other technology, it is naturally also possible to carry out function block integration using this technology. Application of biotechnology is also possible.

[0103] Although the present invention has been described above with embodiments using antennas, the present invention is equally applicable to antenna ports.

[0104] An antenna port refers to a theoretical antenna comprised of one or a plurality of physical antennas. Thus, an antenna port is not limited to mean one physical antenna, and may be for example an array antenna formed by multiple antennas.

[0105] For example, 3 GPP LTE does not define how many physical antennas an antenna port is formed with, but defines that an antenna port is the minimum unit for transmitting different reference signals in a base station.

[0106] In addition, an antenna port may be defined as a minimum unit for multiplying a precoding vector as weighting.

Industrial Applicability



[0107] A radio communication apparatus and reference signal generation method of the present invention are applicable, for example, to a mobile communication system such as an LTE-Advanced system.

Reference Signs List



[0108] 

101, 206 CoMP mode setting section

102, 207 ZC sequence number inside CoMP set setting section

103, 208 ZC sequence number in system setting section

104, 209 Hopping pattern calculation section

105, 210 ZC sequence generation section

106 Mapping section

107, 212 IFFT section

108 CP addition section

109 RF transmission section

110, 210 Antenna

202 RF reception section

203 CP removing section

204 FFT section

205 Demapping section

211 Division section

213 Masking processing section

214 DFT section

215 CQI estimation section




Claims

1. A communication apparatus for a base station (200) comprising:

a transmitter, which, in operation, transmits, to a terminal, information related to a hopping pattern that defines a variation of sequence numbers over time;

a receiver (202), which, in operation, receives, from the terminal, a reference signal generated using a sequence number, the sequence number being calculated using the hopping pattern that is defined differently by whether a Coordinated Multiple Point transmission and reception, CoMP, mode or Non-CoMP mode is set, wherein, when the CoMP mode is set, a plurality of base stations or cells communicate with the terminal in a coordinated manner between the plurality of base stations or cells; and

circuitry (215), which, in operation, estimates a channel quality based on the received reference signal.


 
2. The communication apparatus according to claim 1, wherein the sequence number is calculated by hopping a sequence number that is used in a CoMP set, the CoMP set comprising the plurality of base stations or cells performing communication in the coordinated manner, when the CoMP mode is set.
 
3. The communication apparatus according to claim 1, wherein the sequence number is calculated by hopping a sequence number that is not used in a CoMP set, the CoMP set comprising the plurality of base stations or cells performing communication in the coordinated manner, when the CoMP mode is set.
 
4. The communication apparatus according to claim 1, wherein the sequence number is calculated by hopping a sequence number that is used in CoMP sets in a cell, wherein each of the CoMP sets comprises a plurality of base stations or cells performing communication with a radio communication apparatus in the coordinated manner, when the CoMP mode is set.
 
5. The communication apparatus according to claim 1, wherein the sequence number is calculated by hopping a sequence number that is not used in CoMP sets in a cell, wherein each of the CoMP sets comprises a plurality of base stations or cells performing communication with a radio communication apparatus in the coordinated manner, when the CoMP mode is set.
 
6. The communication apparatus according to claim 1, wherein the sequence number is calculated using the hopping pattern, which is defined based on a cell number, when the Non-CoMP mode is set.
 
7. The communication apparatus according to claim 1, wherein the hopping pattern includes a first hopping pattern and a second hopping pattern different from the first hopping pattern, and the sequence number is calculated using the first hopping pattern when the CoMP mode is set, and the sequence number is calculated using the second hopping pattern when the Non-CoMP mode is set.
 
8. The communication apparatus according to claim 1, wherein when the CoMP mode is set, the terminal transmits a signal to a plurality of cells capable of coordinating a reconstruction of a single signal based each of the plurality of signals received by the cells.
 
9. A reference signal receiving method used by a communication apparatus for a base station comprising:

transmitting, to a terminal, information related to a hopping pattern that defines a variation of sequence numbers over time;

receiving, from the terminal, a reference signal generated using a sequence number, the sequence number being calculated using the hopping pattern that is defined differently by whether a Coordinated Multiple Point transmission and reception, CoMP, mode or Non-CoMP mode is set, wherein, when the CoMP mode is set, a plurality of base stations or cells communicate with the terminal in a coordinated manner between the plurality of base stations or cells; and

estimating a channel quality based on the received reference signal.


 
10. The reference signal receiving method according to claim 9, wherein the sequence number is calculated using the hopping pattern, which is defined based on a cell number, when the Non-CoMP mode is set.
 
11. The reference signal receiving method according to claim 9, wherein the hopping pattern includes a first hopping pattern and a second hopping pattern different from the first hopping pattern, and the sequence number is calculated using the first hopping pattern when the CoMP mode is set, and is calculated using the second hopping pattern when the Non-CoMP mode is set.
 
12. The reference signal receiving method according to claim 9, wherein when the CoMP mode is set, the terminal transmits a signal to a plurality of cells adapted to coordinate a reconstruction of a single signal based on combining each of the plurality of signals received by the cells.
 


Ansprüche

1. Funkkommunikationsvorrichtung für eine Basisstation (200), umfassend:

einen Sender, der im Betrieb zu einem Endgerät Informationen sendet, die sich auf ein Hopping-Muster beziehen, das eine Variation einer Sequenzzahl über die Zeit definiert;

einen Empfänger (202), der im Betrieb von dem Endgerät ein Bezugssignal empfängt, das unter Verwendung einer Sequenzzahl erzeugt wird, wobei die Sequenzzahl unter Verwendung des Hopping-Musters berechnet wird, das unterschiedlich dadurch definiert wird, ob ein CoMP-, Coordinated-Multiple-Point-Sende-und-Empfangsmodus oder ein Nicht-CoMP-Modus eingestellt ist, wobei, wenn der CoMP-Modus eingestellt ist, zahlreiche Basisstationen oder Zellen mit dem Endgerät auf koordinierte Weise zwischen den zahlreichen Basisstationen oder Zellen kommunizieren; und

eine Schaltung (215), die im Betrieb eine Kanalqualität auf der Basis des empfangenen Referenzsignals schätzt.


 
2. Kommunikationsvorrichtung nach Anspruch 1, bei der die Sequenzzahl durch Hopping einer Sequenzzahl berechnet wird, die in einem CoMP-Satz verwendet wird, wobei der CoMP-Satz die zahlreichen Basisstationen oder Zellen umfasst, die eine Kommunikation koordiniert durchführen, wenn der CoMP-Modus eingestellt ist.
 
3. Kommunikationsvorrichtung nach Anspruch 1, bei der die Sequenzzahl durch Hopping einer Sequenzzahl berechnet wird, die nicht in einem CoMP-Satz verwendet wird, wobei der CoMP-Satz die zahlreichen Basisstationen oder Zellen umfasst, die die Kommunikation koordiniert durchführen, wenn der CoMP-Modus eingestellt ist.
 
4. Kommunikationsvorrichtung nach Anspruch 1, bei der die Sequenzzahl durch Hopping einer Sequenzzahl berechnet wird, die in CoMP-Sätzen in einer Zelle verwendet wird, wobei jeder der CoMP-Sätze eine Vielzahl von Basisstationen oder Zellen umfasst, die die Kommunikation mit einer Funkkommunikationsvorrichtung auf koordinierte Weise durchführen, wenn der CoMP-Modus eingestellt ist.
 
5. Kommunikationsvorrichtung nach Anspruch 1, bei der die Sequenzzahl durch Hopping einer Sequenzzahl berechnet wird, die nicht in CoMP-Sätzen in einer Zelle verwendet wird, wobei jeder der CoMP-Sätze mehrere Basisstationen oder Zellen umfasst, die die Kommunikation mit einer Funkkommunikationsvorrichtung auf koordinierte Weise durchführen, wenn der CoMP-Modus eingestellt ist.
 
6. Kommunikationsvorrichtung nach Anspruch 1, bei der die Sequenzzahl unter Verwendung des Hopping-Musters berechnet wird, das basierend auf einer Zellenzahl definiert ist, wenn der Nicht-CoMP-Modus eingestellt ist.
 
7. Kommunikationsvorrichtung nach Anspruch 1, bei der das Hopping-Muster ein erstes Hopping-Muster und ein zweites Hopping-Muster, das sich vom ersten Hopping-Muster unterscheidet, enthält, und die Sequenzzahl unter Verwendung des ersten Hopping-Musters berechnet wird, wenn der CoMP-Modus eingestellt ist, und die Sequenzzahl unter Verwendung des zweiten Hopping-Musters berechnet wird, wenn der Nicht-CoMP-Modus eingestellt ist.
 
8. Kommunikationsvorrichtung nach Anspruch 1, bei der, wenn der CoMP-Modus eingestellt ist, das Endgerät ein Signal an eine Vielzahl von Zellen sendet, die in der Lage sind, eine Rekonstruktion eines einzelnen Signals basierend auf jedem der Vielzahl von Signalen zu koordinieren, die von den Zellen empfangen werden.
 
9. Referenzsignal-Empfangsverfahren, das von einer Kommunikationsvorrichtung für eine Basisstation verwendet wird, umfassend:

Senden, zu einem Endgerät, von Informationen, die sich auf ein Hopping-Muster beziehen, das eine Variation von Sequenzzahlen über die Zeit definiert;

Empfangen, von dem Endgerät, eines Referenzsignals, das unter Verwendung der Sequenzzahl erzeugt wird, wobei die Sequenzzahl unter Verwendung des Hopping-Musters berechnet wird, das unterschiedlich dadurch definiert wird, ob ein CoMP-, Coordinated-Multiple-Point-Sende-und-Empfangsmodus oder ein Nicht-CoMP-Modus eingestellt ist, wobei, wenn der CoMP-Modus eingestellt ist, zahlreiche Basisstationen oder Zellen mit dem Endgerät auf koordinierte Weise zwischen den zahlreichen Basisstationen oder Zellen kommunizieren; und

Schätzen einer Kanalqualität auf der Basis des empfangenen Referenzsignals.


 
10. Referenzsignal-Empfangsverfahren nach Anspruch 9, bei dem die Sequenzzahl unter Verwendung des Hopping-Musters berechnet wird, das auf der Basis einer Zellenzahl definiert ist, wenn der Nicht-CoMP-Modus eingestellt ist.
 
11. Referenzsignal-Empfangsverfahren nach Anspruch 9, bei dem das Hopping-Muster ein erstes Hopping-Muster und ein zweites Hopping-Muster, das sich vom ersten Hopping-Muster unterscheidet, enthält, und die Sequenzzahl unter Verwendung des ersten Hopping-Musters berechnet wird, wenn der CoMP-Modus eingestellt ist, und unter Verwendung des zweiten Hopping-Musters berechnet wird, wenn der Nicht-CoMP-Modus eingestellt ist.
 
12. Referenzsignal-Empfangsverfahren nach Anspruch 9, bei dem, wenn der CoMP-Modus eingestellt ist, das Endgerät ein Signal an eine Vielzahl von Zellen sendet, die dazu eingerichtet sind, eine Rekonstruktion eines einzelnen Signals basierend auf Kombination jedes der Vielzahl von Signalen zu koordinieren, die von den Zellen empfangen werden.
 


Revendications

1. Appareil de communication pour une station de base (200) comprenant :

un émetteur qui, en fonctionnement, transmet, à un terminal, des informations liées à un motif de saut qui définit une variation de numéros de séquence dans le temps ;

un récepteur (202), qui, en fonctionnement, reçoit, en provenance du terminal, un signal de référence généré en utilisant un numéro de séquence, le numéro de séquence étant calculé en utilisant le motif de saut qui est défini différemment selon qu'un mode de transmission et de réception multipoint coordonnée, CoMP, ou qu'un mode Non-CoMP est établi, dans lequel, lorsque le mode CoMP est établi, une pluralité de stations de base ou de cellules communiquent avec le terminal d'une manière coordonnée entre la pluralité de stations de base ou de cellules ; et

un circuit (215) qui, en fonctionnement, estime une qualité de canal sur la base du signal de référence reçu.


 
2. Appareil de communication selon la revendication 1, dans lequel le numéro de séquence est calculé en sautant un numéro de séquence qui est utilisé dans un ensemble CoMP, l'ensemble CoMP comprenant la pluralité de stations de base ou cellules effectuant une communication de la manière coordonnée, lorsque le mode CoMP est établi.
 
3. Appareil de communication selon la revendication 1, dans lequel le numéro de séquence est calculé en sautant un numéro de séquence qui n'est pas utilisé dans un ensemble CoMP, l'ensemble CoMP comprenant la pluralité de stations de base ou cellules effectuant une communication de la manière coordonnée, lorsque le mode CoMP est établi.
 
4. Appareil de communication selon la revendication 1, dans lequel le numéro de séquence est calculé en sautant un numéro de séquence qui est utilisé dans des ensembles CoMP dans une cellule, dans lequel chacun des ensembles CoMP comprend une pluralité de stations de base ou cellules effectuant une communication avec un appareil de radiocommunication de la manière coordonnée, lorsque le mode CoMP est établi.
 
5. Appareil de communication selon la revendication 1, dans lequel le numéro de séquence est calculé en sautant un numéro de séquence qui n'est pas utilisé dans des ensembles CoMP dans une cellule, dans lequel chacun des ensembles CoMP comprend une pluralité de stations de base ou cellules effectuant une communication avec un appareil de radiocommunication de la manière coordonnée, lorsque le mode CoMP est établi.
 
6. Appareil de communication selon la revendication 1, dans lequel le numéro de séquence est calculé en utilisant le motif de saut, qui est défini sur la base d'un numéro cellule, lorsque le mode Non-CoMP est établi.
 
7. Appareil de communication selon la revendication 1, dans lequel le motif de saut comprend un premier motif de saut et un second motif de saut différent du premier motif de saut, et le numéro de séquence est calculé en utilisant le premier motif de saut lorsque le mode CoMP est établi, et le numéro de séquence est calculé en utilisant le second motif de saut lorsque le Non-CoMP est établi.
 
8. Appareil de communication selon la revendication 1, dans lequel lorsque le mode CoMP est établi, le terminal transmet un signal à une pluralité de cellules capables de coordonner une reconstruction d'un signal unique sur la base de chacun de la pluralité de signaux reçus par les cellules.
 
9. Procédé de réception de signal de référence utilisé par un appareil de communication pour une station de base comprenant les étapes consistant à :

transmettre, à un terminal, des informations liées à un motif de saut qui définit une variation de numéros de séquence dans le temps ;

recevoir, en provenance du terminal, un signal de référence généré en utilisant un numéro de séquence, le numéro de séquence étant calculé en utilisant le motif de saut qui est défini différemment selon qu'un mode de transmission et de réception multipoint coordonnée, CoMP, ou qu'un mode Non-CoMP est établi, dans lequel, lorsque le mode CoMP est établi, une pluralité de stations de base ou de cellules communiquent avec le terminal d'une manière coordonnée entre la pluralité de stations de base ou de cellules ; et

estimer une qualité de canal sur la base du signal de référence reçu.


 
10. Procédé de réception de signal de référence selon la revendication 9, dans lequel le numéro de séquence est calculé en utilisant le motif de saut, qui est défini sur la base d'un numéro de cellule, lorsque le mode Non-CoMP est établi.
 
11. Procédé de réception de signal de référence selon la revendication 9, dans lequel le motif de saut comprend un premier motif de saut et un second motif de saut différent du premier motif de saut, et le numéro de séquence est calculé en utilisant le premier motif de saut lorsque le mode CoMP est établi, et est calculé en utilisant le second motif de saut lorsque le mode Non-CoMP est établi.
 
12. Procédé de réception de signal de référence selon la revendication 9, dans lequel lorsque le mode CoMP est établi, le terminal transmet un signal à une pluralité de cellules adaptées pour coordonner une reconstruction d'un signal unique sur la base d'une combinaison de chacun de la pluralité de signaux reçus par les cellules.
 




Drawing
































Cited references

REFERENCES CITED IN THE DESCRIPTION



This list of references cited by the applicant is for the reader's convenience only. It does not form part of the European patent document. Even though great care has been taken in compiling the references, errors or omissions cannot be excluded and the EPO disclaims all liability in this regard.

Patent documents cited in the description




Non-patent literature cited in the description