EXTENDED GUARD INTERVAL FOR OUTDOOR WLAN

• US 20160204968A1
• Filed: 03/21/2016
• Published: 07/14/2016
• Est. Priority Date: 09/10/2013
• Status: Active Grant

• Current Assignee: Marvell Asia Pte Limited (Marvell Technology Group Limited)
• Original Assignee: Marvell World Trade Limited (Marvell Technology Group Limited)
• Inventors: ZHANG, Hongyuan
• Granted Patent: US 10,033,563 B2
• Time in Patent Office: Days
• US Class Current: 1/1
• CPC Class Codes: H04L 27/2602 Signal structure
• CPC Class Codes: H04L 27/26025 Numerology, i.e. varying one or more of symbol duration, subcarrier spacing, Fourier transform size, sampling rate or down-clocking allocating sub-channels of the transmission path H04L5/003
• CPC Class Codes: H04L 27/2603 Signal structure ensuring backward compatibility with legacy system
• CPC Class Codes: H04L 27/2605 Symbol extensions, e.g. Zero Tail, Unique Word [UW]
• CPC Class Codes: H04L 27/2607 Cyclic extensions
• CPC Class Codes: H04L 27/2626 Arrangements specific to the transmitter only
• CPC Class Codes: H04W 84/12 WLAN [Wireless Local Area Networks]

Abstract

A wireless network interface device selects a guard interval from a set of guard intervals including a first guard interval, a second guard interval, and a third guard interval, where in the first guard interval has a length that is 50% of a length of the second guard interval, and wherein the length of the second guard interval is 50% of a length of the third guard interval. The wireless network interface device generates a preamble of a data unit to include: a legacy signal field, a repetition of the legacy field, and a non-legacy field that includes a field that indicates the selected guard interval. The wireless network interface device generates a data portion of the data unit, including generating orthogonal frequency division multiplexing (OFDM) symbols of the data portion using the selected guard interval.

Claims

1. A method for generating a data unit for transmission via a wireless communication channel, the method comprising:

selecting, at a wireless network interface device, a guard interval from a set of guard intervals including a first guard interval, a second guard interval, and a third guard interval, where in the first guard interval has a length that is 50% of a length of the second guard interval, and wherein the length of the second guard interval is 50% of a length of the third guard interval;

generating, at the wireless network interface device, a preamble of a data unit to include;

a legacy signal field,

a repetition of the legacy field, and

a non-legacy field that includes a field that indicates the selected guard interval; and

generating, at the wireless network interface device, a data portion of the data unit, including generating orthogonal frequency division multiplexing (OFDM) symbols of the data portion using the selected guard interval.

2. The method of claim 1, wherein the field that indicates the selected guard interval comprises two bits.

3. The method of claim 1, wherein generating the preamble includes:

generating a first portion of the preamble, wherein the first portion of the preamble is (i) generated using one of the first guard interval, the second guard interval, and the third guard interval that is different than the selected guard interval, and (ii) includes the legacy signal field, and

generating a second portion of the preamble using the selected guard interval.

4. The method of claim 3, wherein the second portion of the preamble includes the non-legacy signal field.

5. The method of claim 1, wherein the data unit conforms to a first communication protocol, and wherein generating the preamble further comprises generating the preamble such that (i) a legacy receiver configured to operate according to a legacy communication protocol but not according to the first communication protocol can determine a duration of the data unit by decoding the legacy signal field, and (ii) a receiver configured to operate according to the first communication protocol can detect that the data unit conforms to the first communication protocol.

6. The method of claim 1, further comprising:

transmitting, with the wireless network interface device, the data unit via one or more antennas.

7. An apparatus comprising:

a wireless network interface device having one or more integrated circuits configured to

select a guard interval from a set of guard intervals including a first guard interval, a second guard interval, and a third guard interval, where in the first guard interval has a length that is 50% of a length of the second guard interval, and wherein the length of the second guard interval is 50% of a length of the third guard interval, and

generate a preamble of a data unit to include;

a legacy signal field,

a repetition of the legacy field, and

a non-legacy field that includes a field that indicates the selected guard interval; and

wherein the one or more integrated circuits are further configured to generate a data portion of the data unit, including generating orthogonal frequency division multiplexing (OFDM) symbols of the data portion using the selected guard interval.

8. The apparatus of claim 7, wherein the field that indicates the selected guard interval comprises two bits.

9. The apparatus of claim 7, wherein the one or more integrated circuits are further configured to:

generate a first portion of the preamble, wherein the first portion of the preamble is (i) generated using one of the first guard interval, the second guard interval, and the third guard interval that is different than the selected guard interval, and (ii) includes the legacy signal field; and

generate a second portion of the preamble using the selected guard interval.

10. The apparatus of claim 9, wherein the second portion of the preamble includes the non-legacy signal field.

11. The apparatus of claim 7, wherein the data unit conforms to a first communication protocol, and wherein the one or more integrated circuits are further configured to:

generate the preamble such that (i) a legacy receiver configured to operate according to a legacy communication protocol but not according to the first communication protocol can determine a duration of the data unit by decoding the legacy signal field, and (ii) a receiver configured to operate according to the first communication protocol can detect that the data unit conforms to the first communication protocol.

12. A tangible, non-transitory computer readable medium, or media, storing machine readable instructions that, when executed by one or more processors, cause the one or more processors to:

select a guard interval from a set of guard intervals including a first guard interval, a second guard interval, and a third guard interval, where in the first guard interval has a length that is 50% of a length of the second guard interval, and wherein the length of the second guard interval is 50% of a length of the third guard interval;

cause a wireless network interface device to generate a preamble of a data unit to include;

a legacy signal field,

a repetition of the legacy field, and

a non-legacy signal field that includes a field that indicates the selected guard interval;

cause the wireless network interface device to generate a data portion of the data unit, including generating orthogonal frequency division multiplexing (OFDM) symbols of the data portion using the selected guard interval; and

cause the wireless network interface device to transmit the data unit via a wireless communication channel.

13. The computer readable medium, or media, of claim 12, wherein the field that indicates the selected guard interval comprises two bits.

14. The computer readable medium, or media, of claim 12, further storing machine readable instructions that, when executed by the one or more processors, cause the one or more processors to:

generate a first portion of the preamble, wherein the first portion of the preamble is (i) generated using one of the first guard interval, the second guard interval, and the third guard interval that is different than the selected guard interval, and (ii) includes the legacy signal field; and

generate a second portion of the preamble using the selected guard interval.

15. The computer readable medium, or media, of claim 14, wherein the second portion of the preamble includes the non-legacy signal field.

16. The computer readable medium, or media, of claim 12, wherein the data unit conforms to a first communication protocol, and wherein the computer readable medium, or media, further store machine readable instructions that, when executed by the one or more processors, cause the one or more processors to:

generate the preamble such that (i) a legacy receiver configured to operate according to a legacy communication protocol but not according to the first communication protocol can determine a duration of the data unit by decoding the legacy signal field, and (ii) a receiver configured to operate according to the first communication protocol can detect that the data unit conforms to the first communication protocol.