Terminal device, base station device, and communication method

• US 10,455,571 B2
• Filed: 01/18/2018
• Issued: 10/22/2019
• Est. Priority Date: 01/30/2012
• Status: Active Grant

• Current Assignee: Sun Patent Trust
• Original Assignee: Sun Patent Trust
• Inventors: Takeda, Kazuki, Nishio, Akihiko, Imamura, Daichi, Ogawa, Yoshihiko
• Primary Examiner(s): Mattis, Jason E
• Assistant Examiner(s): Ahmed, Nizam U
• Application Number:
  US15/874,201
• Publication Number:
  US 20180146459A1
• Time in Patent Office: 642 Days
• CPC Class Codes: H04J 11/005 of intercell interference
• CPC Class Codes: H04J 13/16 Code allocation
• CPC Class Codes: H04L 27/2613 Structure of the reference signals
• CPC Class Codes: H04L 27/26134 Pilot insertion in the transmitter chain, e.g. pilot overlapping with data, insertion in time or frequency domain
• CPC Class Codes: H04L 5/0032 Distributed allocation, i.e. involving a plurality of allocating devices, each making partial allocation
• CPC Class Codes: H04W 24/02 Arrangements for optimising operational condition
• CPC Class Codes: H04W 72/0466 the resource being a scrambling code
• CPC Class Codes: H04W 72/23 in the downlink direction of a wireless link, i.e. towards a terminal

Abstract

A terminal device is equipped with: a sequence determination unit that determines a sequence number with a different pattern than the assignment pattern for the sequence number assigned to the cell in which the host device resides; a reference signal generation unit that generates a reference signal for a sequence group corresponding to the sequence number that has been determined; and a wireless transmission unit that transmits the reference signal that has been generated to a base station. The sequence determination unit employs a configuration whereby, with the sequence number assigned to the cell in which the host device resides as a cell-specific sequence number, a dynamic offset which periodically changes over time and for which the same value is not consecutive is added to the cell-specific sequence number, thereby determining a sequence number which never overlaps with the cell-specific sequence number.

Claims

1. A radio communication terminal comprising:

a controller, which,

in response to receiving signaling specific to the radio communication terminal, determines a base sequence group based on the received signaling; and

in response to not receiving signaling specific to the radio communication terminal, determines a base sequence group which is allocated to a cell that contains the radio communication terminal;

wherein the controller, in operation, generates a sounding reference signal (SRS) using the determined base sequence group; and

a transmitter, which is coupled to the controller and which, in operation, transmits the generated SRS;

wherein the base sequence group determined based on the signaling specific to the radio communication terminal is based on a cell-specific sequence group number, to which a variable offset is added, wherein the variable offset temporally varies to take different values in different time slots in one cycle period.

2. The radio communication terminal according to claim 1, wherein the signaling specific to the radio communication terminal is received before the transmitter transmits the generated SRS.

3. The radio communication terminal according to claim 1, wherein the controller, in response to receiving new signaling specific to the radio communication terminal, updates the determined base sequence group based on the new signaling and generates another SRS using the updated base sequence group.

4. The radio communication terminal according to claim 1, wherein the base sequence group determined based on the signaling specific to the radio communication terminal does not overlap with the base sequence group allocated to the cell that contains the radio communication terminal due to the variable offset.

5. The radio communication terminal according to claim 1, wherein the signaling specific to the radio communication terminal includes 9 bits of a cell ID.

6. A radio communication terminal comprising:

a receiver, which, in operation, receives an instruction specifically signaled to the radio communication terminal by a Radio Resource Control (RRC) layer, the instruction including a parameter of a sequence number;

a controller, which is coupled to the receiver and which, in operation, configures a sequence number based on the received instruction, ignoring a sequence number allocated to a cell that contains the radio communication terminal, and generates a Sounding Reference Signal (SRS) of a sequence group corresponding to the configured sequence number; and

a transmitter, which is coupled to the controller and which, in operation, transmits the generated SRS,

wherein the sequence group corresponding to the configured sequence number is based on a cell-specific sequence group number, to which a variable offset is added, wherein the variable offset temporally varies to take different values in different time slots in one cycle period.

7. The radio communication terminal according to claim 6,

wherein a number of times sequence numbers respectively allocated to neighboring cells overlap with the configured sequence number of the radio communication terminal in one cycle period of cyclically repeated sequence number allocation is not concentrated in any one of the neighboring cells.

8. The radio communication terminal according to claim 7, wherein a difference among the numbers of times sequence numbers respectively allocated to neighboring cells overlap with the configured sequence number of the radio communication terminal in one cycle period is at most three.

17. The radio communication terminal according to claim 6, wherein,

the sequence number is represented by an integer modulo N_SG, and

the variable offset satisfies equations (1) to (3) below:

F(n_s)mod N_SG≠

0 

 

(1)

Pr[F(n_s)=x]≤

3/X 

 

(2)

X≥

0.5×

N_TS 

 

(3)

where n_s is a time slot;

F(n_s) is a value of the variable offset in the time slot n_s;

N_SG is a number of sequence groups, or a number of cells belonging to one cell cluster;

Pr represents a probability to satisfy an expression in brackets;

X is an element number of a set of all the values taken as value x of the variable offset; and

N_TS is a number of time slots in one cycle period.

18. The radio communication terminal according to claim 17, wherein,

the variable offset F(n_s) is represented by equation (4) below:

F(n_s)=λ

×

ns+z 

 

(4)

where λ and

z are integers other than zero and satisfying the equations (1) to (3).

9. A method performed by a radio communication terminal, the method comprising:

in response to receiving signaling specific to the radio communication terminal, determining a base sequence group based on the received signaling;

in response to not receiving signaling specific to the radio communication terminal, determining a base sequence group which is allocated to a cell that contains the radio communication terminal;

generating a sounding reference signal (SRS) using the determined base sequence group; and

transmitting the generated SRS,

wherein the base sequence group determined based on the signaling specific to the radio communication terminal is based on a cell-specific sequence group number, to which a variable offset is added, wherein the variable offset temporally varies to take different values in different time slots in one cycle period.

10. The method according to claim 9, wherein the signaling specific to the radio communication terminal is received before the generated SRS is transmitted.

11. The method according to claim 9, comprising:

in response to receiving new signaling specific to the radio communication terminal, updating the determined base sequence group based on the new signaling and generating another SRS using the updated base sequence group.

12. The method according to claim 9, wherein the base sequence group determined based on the signaling specific to the radio communication terminal does not overlap with the base sequence group allocated to the cell that contains the radio communication terminal due to the variable offset.

13. The method according to claim 9, wherein the signaling specific to the radio communication terminal includes 9 bits of a cell ID.

14. A method performed by a radio communication terminal, the method comprising:

receiving an instruction specifically signaled to the radio communication terminal by a Radio Resource Control (RRC) layer, the instruction including a parameter of a sequence number;

configuring a sequence number based on the received instruction, ignoring a sequence number allocated to a cell that contains the radio communication terminal;

generating a Sounding Reference Signal (SRS) of a sequence group corresponding to the configured sequence number; and

transmitting the generated SRS,

wherein the sequence group corresponding to the configured sequence number is based on a cell-specific sequence group number, to which a variable offset is added, wherein the variable offset temporally varies to take different values in different time slots in one cycle period.

15. The method according to claim 14,

wherein a number of times sequence numbers respectively allocated to neighboring cells overlap with the configured sequence number of the radio communication terminal in one cycle period of cyclically repeated sequence number allocation is not concentrated in any one of the neighboring cells.

16. The method according to claim 15, wherein a difference among the numbers of times sequence numbers respectively allocated to neighboring cells overlap with the configured sequence number of the radio communication terminal in one cycle period is at most three.

19. The method according to claim 14, wherein,

the sequence number is represented by an integer modulo N_SG, and

the variable offset satisfies equations (1) to (3) below:

F(n_s)mod N_SG≠

0 

 

(1)

Pr[F(n_s)=x]≤

3/X 

 

(2)

X≥

0.5×

N_TS 

 

(3)

where n_s is a time slot;

F(n_s) is a value of the variable offset in the time slot n_s;

N_SG is a number of sequence groups, or a number of cells belonging to one cell cluster;

Pr represents a probability to satisfy an expression in brackets;

X is an element number of a set of all the values taken as value x of the variable offset; and

N_Ts is a number of time slots in one cycle period.

20. The method according to claim 19, wherein,

the variable offset F(n_s) is represented by equation (4) below:

F(n_s)=λ

×

ns+z 

 

(4)

where λ and

z are integers other than zero and satisfying the equations (1) to (3).