Method and apparatus for setting a guard interval in an OFDM communication

• US 20040160987A1
• Filed: 02/09/2004
• Published: 08/19/2004
• Est. Priority Date: 12/22/1998
• Status: Active Grant

• Current Assignee: Matsushita Electric Industrial Company Limited (Panasonic Holdings Corporation)
• Original Assignee: Matsushita Electric Industrial Company Limited (Panasonic Holdings Corporation)
• Inventors: Sudo, Hiroaki, Uesugi, Mitsuru
• Granted Patent: US 7,403,471 B2
• Time in Patent Office: Days
• US Class Current: 370/480
• CPC Class Codes: H04L 27/2605 Symbol extensions, e.g. Zero Tail, Unique Word [UW]

Abstract

A method and appparatus for setting a guard interval in an OFDM communication. The method includes attaching a part of a first valid symbol to the first valid symbol as a guard interval and attaching a part of a second valid symbol requiring higher channel quality than the first valid symbol, to the second valid symbol as a guard interval, and providing the guard interval of the second valid symbol at a length greater than the guard interval of the first valid symbol.

Claims

1. A method of setting a guard interval in an OFDM communication, comprising:

attaching a part of a first valid symbol to the first valid symbol as a guard interval;

attaching a part of a second valid symbol requiring higher channel quality than the first valid symbol, to the second valid symbol as a guard interval; and

providing the guard interval of the second valid symbol at a length greater than the guard interval of the first valid symbol.

2. The method of claim 1, further comprising maintaining the length of the first valid symbol and the second valid symbol.

3. The method of claim 1, further comprising:

inserting user data in the first valid symbol; and

inserting control data in the second valid symbol.

4. The method of claim 1, further comprising changing the length of the guard interval of the first valid symbol in accordance with channel quality.

5. The method of claim 1, further comprising maintaining the length of the guard interval of the second valid symbol.

6. The method of claim 1, further comprising maintaining the length of the guard interval of the second valid symbol at a predetermined length greater than the guard interval of the first valid symbol.

7. The method of claim 1, further comprising forming the guard interval of the second valid symbol by attaching a length that changes in accordance with channel quality of the guard interval of the first valid symbol.

8. A method of setting a guard interval in an OFDM communication, comprising:

attaching a part of the first valid symbol to the first valid symbol as a guard interval;

attaching a part of a second valid symbol requiring higher channel quality than the first valid symbol, to the second valid symbol as a guard interval; and

changing the length of the guard interval of the first valid symbol in accordance with channel quality while maintaining the length of the guard interval of the second valid symbol.

9. A method of setting a guard interval in an OFDM communication, comprising:

attaching a part of a valid symbol to the valid symbol as a guard interval; and

providing the guard interval at a greater length when the valid symbol requires higher quality.

10. A method of setting a guard interval in an OFDM communication, comprising:

attaching a part of a valid symbol to the valid symbol as a guard interval; and

providing a guard interval of a valid symbol including control data at a length greater than a guard interval of a valid symbol including user data.

11. An OFDM communication apparatus comprising:

an attacher configured to attach a part of a first valid symbol to the first valid symbol as a guard interval, and further configured to attach a part of a second valid symbol requiring higher channel quality than the first valid symbol as a guard interval; and

a provider configured to provide the guard interval of the second valid symbol at a length greater than the guard interval of the first valid symbol.