COMMUNICATION APPARATUS, COMMUNICATION METHOD, COMPUTER PROGRAM, AND COMMUNICATION SYSTEM

• US 20120057622A1
• Filed: 04/19/2010
• Published: 03/08/2012
• Est. Priority Date: 05/08/2009
• Status: Active Grant

• Current Assignee: Sony Corporation (Sony Group Corp.)
• Original Assignee: Sony Corporation (Sony Group Corp.)
• Inventors: Kimura, Ryota, Sakoda, Kazuyuki, Morioka, Yuichi
• Granted Patent: US 8,982,930 B2
• Time in Patent Office: Days
• US Class Current: 375/219
• CPC Class Codes: H04B 7/0452 Multi-user MIMO systems
• CPC Class Codes: H04W 56/0045 compensating for timing error by altering transmission time
• CPC Class Codes: H04W 72/046 the resource being in the space domain, e.g. beams

Abstract

Appropriate communication operation is performed by employing space division multiple access in which wireless resources on a space axis are shared by a plurality of users.

Frame exchange is performed between an access point and terminals whereby the access point estimates delay times of the terminals and notifies the terminals of information on the delay times and the terminals perform uplink frame transmission to the access point taking a difference among the delay times into consideration. Interference among users may be reduced in the access point and throughput of a system which performs the space division multiple access is improved.

Claims

1. A communication apparatus comprising:

a data processor which processes a transmission/reception frame; and

a communication unit which transmits/receives the frame,

wherein the data processor estimates a delay time of a communication partner in accordance with a required period of time from when a reference frame serving as a reference of delay time estimation is transmitted to the communication partner to when a response frame supplied from the communication partner is received.

2. The communication apparatus according to claim 1,

wherein the communication partner starts transmission of the response frame without back-off when a given frame interval has been elapsed after the reception of the reference frame is completed, and

the data processor estimates the delay time of the communication partner taking the required period of time and the frame interval into consideration.

3. The communication apparatus according to claim 1,

wherein the communication partner starts transmission of the response frame including information on an arbitrary waiting time when the waiting time has been elapsed after the reception of the reference frame is completed, and

the data processor estimates the delay time of the communication partner taking the required period of time and the waiting time obtained from the response frame into consideration.

4. The communication apparatus according to claim 1,

wherein the communication unit includes a plurality of antenna elements functioning as an adaptive array antenna, multiplexes and transmits the plurality of frames on the same time, and receives a plurality of frames transmitted from a plurality of communication partners on the same time.

5. The communication apparatus according to claim 4,

wherein the communication unit transmits the reference frame to the communication partners, and

the data processor estimates delay times of the communication partners in accordance with required periods of times until the response frames return from the communication partners such that at least portions of the reference frames overlap with one another on a time axis.

6. The communication apparatus according to claim 1,

wherein the data processor stores information on the estimated delay time or updates information on an estimated delay time which has been stored.

7. The communication apparatus according to claim 1,

wherein the data processor determines information on the estimated delay time and generates a notification frame including the information on the delay time, and

the communication unit transmits the notification frame to the communication partner.

8. The communication apparatus according to claim 7,

wherein the data processor determines the information on the delay time in accordance with a result of a comparison between the estimated delay time and a predetermined threshold value.

9. The communication apparatus according to claim 7,

wherein the communication unit transmits the reference frame to the plurality of communication partners,

the data processor determines information on the delay times of the communication partners and generates a notification frame, and

the communication unit transmits the notification frame to the communication partners on the same time.

10. A communication apparatus comprising:

a data processor which processes a transmission/reception frame; and

a communication unit which transmits/receives the frame,

wherein the data processor extracts information on a delay time of the data processor from a notification frame transmitted from a communication partner, and

the communication unit controls a transmission timing in accordance with the information on the delay time and transmits a frame to the communication partner.

11. A communication method comprising:

a step of transmitting a reference frame serving as a reference of delay time estimation to a communication partner;

a step of estimating a delay time of the communication partner in accordance with a required period of time until a response frame transmitted from the communication partner is received;

a step of determining information on the estimated delay time and generating a notification frame including the information on the delay time; and

a step of transmitting the notification frame to the communication partner.

12. A communication method comprising:

a step of receiving a notification frame transmitted from a communication partner;

a step of extracting information on a delay time of own apparatus from the notification frame; and

a step of controlling a transmission timing in accordance with the information on the delay time and transmitting a frame to the communication partner.

13. A computer-readable program which causes a communication apparatus to execute a process of transmitting a frame in a computer, the compute-readable program causes the computer to function as:

a data processor which processes a transmission/reception frame; and

a communication unit which transmits/receives the frame,

wherein the data processor estimates a delay time of a communication partner in accordance with a required period of time from when a reference frame serving as a reference of delay time estimation is transmitted to the communication partner to when a response frame supplied from the communication partner is received.

14. A computer-readable program which causes a communication apparatus to execute a process of transmitting a frame in a computer, the compute-readable program causes the computer to function as:

a data processor which processes a transmission/reception frame; and

a communication unit which transmits/receives the frame,

wherein the data processor extracts information on a delay time of the data processor from a notification frame transmitted from a communication partner, and

the communication unit controls a transmission timing in accordance with the information on the delay time and transmits a frame to the communication partner.

15. A communication system comprising:

a first communication apparatus which estimates a delay time of a communication partner in accordance with a required period of time from when a reference frame serving as a reference of delay time estimation is transmitted to the communication partner to when a response frame supplied from the communication partner is received and which transmits a notification frame including information on the delay time to the communication partner; and

a plurality of second communication apparatuses which return response frames in response to reception of the reference frame and which control timings of transmission of frames to the first communication apparatus in accordance with the information on delay times included in the notification frame.