TRANSMISSION APPARATUS, RECEPTION APPARATUS, COMMUNICATION SYSTEM, AND PROCESSING METHOD USED IN RECEPTION APPARATUS

• US 20110222429A1
• Filed: 11/25/2009
• Published: 09/15/2011
• Est. Priority Date: 11/25/2008
• Status: Active Grant

• Current Assignee: Sony Corporation (Sony Group Corp.)
• Original Assignee: Sony Corporation (Sony Group Corp.)
• Inventors: Ito, Osamu
• Granted Patent: US 8,588,098 B2
• Time in Patent Office: Days
• US Class Current: 370/252
• CPC Class Codes: H04L 27/2613 Structure of the reference signals
• CPC Class Codes: H04W 74/0833 Random access procedures, e.g. with 4-step access

Abstract

The present invention relates to a transmission apparatus, a reception apparatus, a communication system, and a processing method used in the reception apparatus that are capable of reducing collisions of an Ack frame.

A transmission apparatus 100 transmits an Ack frame 200 made up of only a PLCP preamble. In a reception apparatus 300, an RF unit 320 supplies the Ack frame 200 received by an antenna 310 to a PMD unit 340. The PMD unit 340 determines a termination end of the Ack frame 200 on the basis of a signal strength of the Ack frame 200 supplied from the RF unit 320. Furthermore, the PMD unit 340 generates a timing of the termination end of the PLCP preamble of the Ack frame 200 on the basis of the PLCP preamble. A PLCP unit 350 detects the Ack frame 200 on the basis of a result in which the termination end of the Ack frame 200 has been determined using the signal strength and the timing of the termination end of the PLCP preamble generated by the PLCP preamble of the Ack frame 200.

Claims

1. A transmission apparatus comprising:

a preamble generating unit that generates only a preamble for adjusting carrier frequency error of a high-frequency signal, the preamble serving as an acknowledgement frame for confirmation of reception; and

a transmitting unit that transmits the acknowledgement frame generated by the preamble generating unit as the high-frequency signal.

2. A reception apparatus comprising:

a receiving unit that receives a packet signal including a preamble;

a signal strength determining unit that determines a termination end of the packet signal on the basis of a strength of the signal received by the receiving unit;

a timing generating unit that generates a timing of a termination end of the preamble by detecting the preamble; and

an acknowledgement frame detecting unit that detects that the packet signal is an acknowledgement frame made up of only the preamble on the basis of a result in which the termination end of the packet signal has been determined by the signal strength determining unit and the timing of the termination end of the preamble generated by the timing generating unit.

3. The reception apparatus according to claim 2, wherein the acknowledgement frame detecting unit detects that the packet signal is the acknowledgement frame on the basis of an estimated period and the result in which the termination end of the packet signal has been determined, the estimated period being a period in which the signal strength determining unit determines a termination end of the acknowledgement frame and which is estimated on the basis of the timing of the termination end of the preamble.

4. The reception apparatus according to claim 2, further comprising:

a decoding unit that decodes the packet signal received by the receiving unit; and

an acknowledgement data detecting unit that detects that data decoded by the decoding unit is data representing an acknowledgement.

5. The reception apparatus according to claim 2, wherein the signal strength determining unit determines the termination end of the packet signal on the basis of the strength of the signal received by the receiving unit and a certain threshold.

6. The reception apparatus according to claim 5, wherein the signal strength determining unit determines the termination end of the packet signal on the basis of an amount of change in the strength of the signal received by the receiving unit.

7. The reception apparatus according to claim 5, wherein the signal strength determining unit sets the threshold on the basis of a strength of the signal before the packet signal is received by the receiving unit.

8. A communication system comprising:

a transmission apparatus that transmits an acknowledgement frame made up of only a preamble; and

a reception apparatus that includes a receiving unit that receives the acknowledgement frame as a packet signal transmitted from the transmission apparatus, a signal strength determining unit that determines a termination end of the packet signal on the basis of a strength of the signal received by the receiving unit, a timing generating unit that generates a timing of a termination end of the preamble by detecting the preamble, and an acknowledgement frame detecting unit that detects that the packet signal is the acknowledgement frame on the basis of a result in which the termination end of the packet signal has been determined by the signal strength determining unit and the timing of the termination end of the preamble generated by the timing generating unit.

9. An acknowledgement frame detection method comprising:

a reception procedure of receiving a packet signal including a preamble;

a signal strength determination procedure of determining a termination end of the packet signal on the basis of a strength of the signal received by the receiving unit;

a timing generation procedure of generating a timing of a termination end of the preamble by detecting the preamble; and

an acknowledgement frame detection procedure of detecting that the packet signal is an acknowledgement frame made up of only the preamble on the basis of a result in which the termination end of the packet signal has been determined in the signal strength determination procedure and the timing of the termination end of the preamble generated in the timing generation procedure.