Terminal station apparatus, base station apparatus, transmission method and control method

• US 9,537,596 B2
• Filed: 06/23/2016
• Issued: 01/03/2017
• Est. Priority Date: 10/01/2009
• Status: Active Grant

• Current Assignee: Sun Patent Trust
• Original Assignee: Sun Patent Trust
• Inventors: Ogawa, Yoshihiko, Nishio, Akihiko, Iwai, Takashi, Nakao, Seigo, Imamura, Daichi, Sumasu, Atsushi
• Primary Examiner(s): Mohebbi, Kouroush
• Application Number:
  US15/191,317
• Publication Number:
  US 20160308634A1
• Time in Patent Office: 194 Days
• Field of Search: None
• US Class Current: 1/1
• CPC Class Codes: H04B 7/0452 Multi-user MIMO systems
• CPC Class Codes: H04B 7/0689 using different transmission schemes, at least one of them being a diversity transmission scheme
• CPC Class Codes: H04J 11/003 at the transmitter transmission to multiple receive units in multiple input multiple output [MIMO] H04B7/0452; transmit antenna weighting H04B7/0615
• CPC Class Codes: H04J 13/0048 Walsh
• CPC Class Codes: H04J 13/18 Allocation of orthogonal codes
• CPC Class Codes: H04L 5/005 of common pilots, i.e. pilots destined for multiple users or terminals
• CPC Class Codes: H04W 72/23 in the downlink direction of a wireless link, i.e. towards a terminal
• CPC Class Codes: H04W 72/54 based on quality criteria
• CPC Class Codes: H04W 88/02 Terminal devices
• CPC Class Codes: H04W 88/08 Access point devices

Abstract

A terminal apparatus is disclosed wherein even in a case of applying SU-MIMO and MU-MIMO at the same time, the inter-sequence interference in a plurality of pilot signals used by the same terminal can be suppressed to a low value, while the inter-sequence interference in pilot signal between terminals can be reduced. In this terminal apparatus: a pilot information deciding unit decides, based on allocation control information, Walsh sequences of the respective ones of first and second stream groups at least one of which includes a plurality of streams; and a pilot signal generating unit forms a transport signal by using the decided Walsh sequences to spread the streams included in the first and second stream groups. During this, Walsh sequences orthogonal to each other are established in the first and second stream groups, and users are allocated on a stream group-by-stream group basis.

Claims

1. A communication apparatus comprising:

a transmitter, which, in operation, transmits, to a terminal, control information, which determines an association of an orthogonal sequence with each of layer numbers,

a receiver, which, in operation, receives, from the terminal, a reference signal, which is generated using the orthogonal sequence based on the association determined by the control information, and which is multiplexed with a data signal having a bandwidth that is different from a bandwidth of a data signal transmitted by another terminal, the orthogonal sequence being one of a first orthogonal sequence [1, 1] and a second orthogonal sequence [1, −

1],

wherein the layer numbers correspond to a first layer, a second layer, a third layer and a fourth layer, and said control information determines one of a plurality of associations including;

(i) a first association, in which the first orthogonal sequence is associated with each of the first layer and the second layer, and the second orthogonal sequence is associated with each of the third layer and the fourth layer;

(ii) a second association, in which the second orthogonal sequence is associated with each of the first layer and the second layer, and the first orthogonal sequence is associated with each of the third layer and the fourth layer;

(iii) a third association, in which the first orthogonal sequence is associated with each of the first layer, the second layer, the third layer and the fourth layer; and

(iv) a fourth association, in which the second orthogonal sequence is associated with each of the first layer, the second layer, the third layer and the fourth layer.

2. The communication apparatus according to claim 1, wherein the association includes an association of a cyclic shift value with each of the layer numbers, and the receiver, in operation, receives the reference signal, which is generated using the cyclic shift value based on the association determined by the control information.

3. The communication apparatus according to claim 2, wherein:

the cyclic shift value is one of 12 cyclic shift values ranging from 0 to 11;

a difference between cyclic shift values respectively associated with the first layer and the second layer is 6;

a difference between cyclic shift values respectively associated with the third layer and the fourth layer is 6; and

a difference between cyclic shift values respectively associated with the first layer and the third layer is 3.

4. A communication apparatus comprising:

a transmitter, which, in operation, transmits, to a terminal, control information, which determines an association of an orthogonal sequence with each of layer numbers,

a receiver, which, in operation, receives, from the terminal, a reference signal, which is generated using the orthogonal sequence based on the association determined by the control information, and which is multiplexed with a data signal having a bandwidth that is different from a bandwidth of a data signal transmitted by another terminal, the orthogonal sequence being one of a first orthogonal sequence [1, 1] and a second orthogonal sequence [1, −

1],

wherein the layer numbers are consecutive numbers, and said control information determines one of a plurality of associations including;

(i) a first association, in which the first orthogonal sequence is associated with each of the first to the Nw-th layer(s), and the second orthogonal sequence is associated with each of the (Nw+1)-th and subsequent layer(s); and

(ii) a second association, in which the second orthogonal sequence is associated with each of the first to the Nw-th layer(s), and the first orthogonal sequence is associated with each of the (Nw+1)-th and subsequent layer(s), wherein Nw is a positive integer.

5. The communication apparatus according to claim 4, wherein the association includes an association of a cyclic shift value with each of the layer numbers, and the receiver, in operation, receives the reference signal, which is generated using the cyclic shift value based on the association determined by the control information.

6. The communication apparatus according to claim 5, wherein:

the cyclic shift value is one of 12 cyclic shift values ranging from 0 to 11;

a difference between cyclic shift values respectively associated with the first layer and the second layer is 6;

a difference between cyclic shift values respectively associated with the third layer and the fourth layer is 6; and

a difference between cyclic shift values respectively associated with the first layer and the third layer is 3.

7. The communication apparatus according to claim 4, wherein the Nw is variable.

8. The communication apparatus according to claim 4, wherein a number of layers is 4, and the Nw is 2 or 4.

9. The communication apparatus according to claim 4, wherein the layer numbers correspond to the first layer, the second layer, a third layer and a fourth layer, and when the Nw is 2:

in the first association, the first orthogonal sequence is associated with each of the first layer and the second layer, and the second orthogonal sequence is associated with each of the third layer and the fourth layer; and

in the second association, the second orthogonal sequence is associated with each of the first layer and the second layer, and the first orthogonal sequence is associated with each of the third layer and the fourth layer.

10. The communication apparatus according to claim 4, wherein the layer numbers correspond to the first layer, the second layer, a third layer and a fourth layer, and when the Nw is 4:

in the first association, the first orthogonal sequence is associated with each of the first layer, the second layer, the third layer and the fourth layer; and

in the second association, the second orthogonal sequence is associated with the first layer, the second layer, the third layer and the fourth layer.

11. A communication method comprising:

transmitting, to a terminal, control information, which determines an association of an orthogonal sequence with each of layer numbers,

receiving, from the terminal, a reference signal, which is generated using the orthogonal sequence based on the association determined by the control information, and which is multiplexed with a data signal having a bandwidth that is different from a bandwidth of a data signal transmitted by another terminal, the orthogonal sequence being one of a first orthogonal sequence [1, 1] and a second orthogonal sequence [1, −

1],

wherein the layer numbers correspond to a first layer, a second layer, a third layer and a fourth layer, and said control information determines one of a plurality of associations including;

(i) a first association, in which the first orthogonal sequence is associated with each of the first layer and the second layer, and the second orthogonal sequence is associated with each of the third layer and the fourth layer;

(ii) a second association, in which the second orthogonal sequence is associated with each of the first layer and the second layer, and the first orthogonal sequence is associated with each of the third layer and the fourth layer;

(iii) a third association, in which the first orthogonal sequence is associated with each of the first layer, the second layer, the third layer and the fourth layer; and

(iv) a fourth association, in which the second orthogonal sequence is associated with each of the first layer, the second layer, the third layer and the fourth layer.

12. The communication method according to claim 11, wherein the association includes an association of a cyclic shift value with each of the layer numbers, and the receiving includes receiving of the reference signal, which is generated using the cyclic shift value based on the association determined by the control information.

13. The communication method according to claim 12, wherein:

the cyclic shift value is one of 12 cyclic shift values ranging from 0 to 11;

a difference between cyclic shift values respectively associated with the first layer and the second layer is 6;

a difference between cyclic shift values respectively associated with the third layer and the fourth layer is 6; and

a difference between cyclic shift values respectively associated with the first layer and the third layer is 3.

14. A communication method comprising:

transmitting, to a terminal, control information, which determines an association of an orthogonal sequence with each of layer numbers,

receiving, from the terminal, a reference signal, which is generated using the orthogonal sequence based on the association determined by the control information, and which is multiplexed with a data signal having a bandwidth that is different from a bandwidth of a data signal transmitted by another terminal, the orthogonal sequence being one of a first orthogonal sequence [1, 1] and a second orthogonal sequence [1, −

1],

wherein the layer numbers are consecutive numbers, and said control information determines one of a plurality of associations including;

(i) a first association, in which the first orthogonal sequence is associated with each of the first to the Nw-th layer(s), and the second orthogonal sequence is associated with each of the (Nw+1)-th and subsequent layer(s); and

(ii) a second association, in which the second orthogonal sequence is associated with each of the first to the Nw-th layer(s), and the first orthogonal sequence is associated with each of the (Nw+1)-th and subsequent layer(s), wherein Nw is a positive integer.

15. The communication method according to claim 14, wherein the association includes an association of a cyclic shift value with each of the layer numbers, and the receiving includes receiving of the reference signal, which is generated using the cyclic shift value based on the association determined by the control information.

16. The communication method according to claim 15, wherein:

the cyclic shift value is one of 12 cyclic shift values ranging from 0 to 11;

a difference between cyclic shift values respectively associated with the first layer and the second layer is 6;

a difference between cyclic shift values respectively associated with the third layer and the fourth layer is 6; and

a difference between cyclic shift values respectively associated with the first layer and the third layer is 3.

17. The communication method according to claim 14, wherein the Nw is variable.

18. The communication method according to claim 14, wherein a number of layers is 4, and the Nw is 2 or 4.

19. The communication method according to claim 14, wherein the layer numbers correspond to the first layer, the second layer, a third layer and a fourth layer, and when the Nw is 2:

in the first association, the first orthogonal sequence is associated with each of the first layer and the second layer, and the second orthogonal sequence is associated with each of the third layer and the fourth layer; and

in the second association, the second orthogonal sequence is associated with each of the first layer and the second layer, and the first orthogonal sequence is associated with each of the third layer and the fourth layer.

20. The communication method according to claim 14, wherein the layer numbers correspond to the first layer, the second layer, a third layer and a fourth layer, and when the Nw is 4:

in the first association, the first orthogonal sequence is associated with each of the first layer, the second layer, the third layer and the fourth layer; and

in the second association, the second orthogonal sequence is associated with the first layer, the second layer, the third layer and the fourth layer.