Method for generating preamble sequence in wireless LAN system

• US 10,135,662 B2
• Filed: 11/30/2015
• Issued: 11/20/2018
• Est. Priority Date: 12/02/2014
• Status: Active Grant

• Current Assignee: LG Electronics, Inc. (LG Corporation)
• Original Assignee: LG Electronics, Inc. (LG Corporation)
• Inventors: Lee, Kilbom, Cho, Hangyu, Lee, Wookbong, Choi, Jinsoo, Kang, Jiwon
• Primary Examiner(s): Le, Nhan
• Application Number:
  US15/524,873
• Publication Number:
  US 20170373911A1
• Time in Patent Office: 1,086 Days
• CPC Class Codes: H04L 27/26 Systems using multi-frequency codes H04L27/32 takes precedence
• CPC Class Codes: H04L 27/2613 Structure of the reference signals
• CPC Class Codes: H04L 27/26132 using repetition
• CPC Class Codes: H04L 27/2621 Reduction thereof using phase offsets between subcarriers
• CPC Class Codes: H04L 27/2694 adaptive design
• CPC Class Codes: H04L 27/3872 Compensation for phase rotation in the demodulated signal
• CPC Class Codes: H04L 5/0048 Allocation of pilot signals, i.e. of signals known to the receiver
• CPC Class Codes: H04L 5/0053 Allocation of signaling, i.e. of overhead other than pilot signals

Abstract

Disclosed is a sequence generation method comprising: generating a basic sequence structure including C₄₈ having 48 tones, X₆ having six tones, and X₅ having five tones; selecting any one of a plurality of phase rotation factors predetermined for a bandwidth; and generating a sequence to be inputted into a preamble to be transmitted to a terminal, by using the phase rotation factor, applied in basic sequence structural units, and the basic sequence structure.

Claims

1. A method of generating a sequence to be inserted into a preamble by an access point (AP) in a wireless local area network (LAN) system, the method comprising:

generating a basic sequence structure comprising C₄₈ comprising 48 tones and having 12 non-zero values, X₆ comprising 6 tones and having one non-zero value, and X₅ comprising five tones and having one non-zero value;

determining X1 that is a non-zero value included in the X₆ and X2 that is a non-zero value included in the X₅;

selecting any one of a plurality of predetermined phase rotation factors with respect to a bandwidth for communication with a user equipment (UE);

generating the sequence using the basic sequence structure and the selected phase rotation factor; and

transmitting, to a station (STA), the preamble into which the sequence is inserted,

wherein the selected phase rotation factor is applied in a unit of the basic sequence structure that is repeatedly included in the sequence once or more.

2. The method according to claim 1, wherein the basic sequence structure is configured in the form of X₆C_48(1:

24)0₅C<sub>48(25;

48)</sub>X₅, the C<sub>48(1;

24)</sub>, indicates first to 24^th tones of the C₄₈, the C<sub>48(25;

48)</sub>, indicates 25^th to 48^th tones of the C₄₈, and the 0₅ indicates five consecutive 0.

3. The method according to claim 1, wherein the X₆ is configured in the form of [0, 0, 0, 0, X1, 0] and the X₅ is configured in the form of [0, X2, 0, 0, 0].

4. The method according to claim 3, wherein the X1 and the X2 satisfy

5. The method according to claim 1, wherein the basic sequence structure is configured in the form of X₆C_48(1:

24)A₅C<sub>48(25;

48)</sub>X₅, the C<sub>48(1;

24)</sub> indicates first to 24^th tones of the C₄₈, the C<sub>48(25;

48)</sub> indicates 25^th to 48^th tones of the C₄₈, and the A₅ comprises 5 tones and comprises one non-zero value in a central part.

6. The method according to claim 1,

wherein the generating of the sequence comprises:

generating the sequence by repeating the basic sequence structure once when the bandwidth corresponds to 20 MHz;

generating the sequence by repeating the basic sequence structure twice and by using two corresponding phase rotation values when the bandwidth corresponds to 40 MHz; and

generating the sequence by repeating the basic sequence structure four times and using four corresponding phase rotation values when the bandwidth corresponds to 80 MHz.

7. The method according to claim 1,

wherein the generating of the sequence comprises:

generating the sequence by repeating the basic sequence structure once when the bandwidth corresponds to 20 MHz;

generating the sequence by repeating a new sequence, in which the X5 and the X6 are removed from the basic sequence structure, twice and by using two corresponding phase rotation values, A11, X5 and X6 when the bandwidth corresponds to 40 MHz; and

generating the sequence by repeating the new sequence, in which the X5 and the X6 are removed from the basic sequence structure, and by using two corresponding phase rotation values when the bandwidth corresponds to 80 MHz.

8. The method according to claim 7, wherein the A₁₁ is configured in the form of [0, A2, 0, 0, 0, A3, 0, 0, 0, A4, 0] and the A2, A3, and A4 are complex numbers that are not 0.

9. An access point (AP) for generating a sequence to be inserted into a preamble in a wireless local area network (LAN) system, the AP comprising:

a transmitter;

a receiver; and

a processor connected to the transmitter and the receiver and configured to;

generate a basic sequence structure comprising C₄₈ comprising 48 tones and having 12 non-zero values, X₆ comprising 6 tones and having one non-zero value, and X₅ comprising five tones and having one non-zero value,

determine X1 that is a non-zero value included in the X₆ and X2 that is a non-zero value included in the X₅,

selects any one of a plurality of predetermined phase rotation factors with respect to a bandwidth for communication with a user equipment (UE),

generate the sequence inserted into the preamble to be transmitted to the UE using the basic sequence structure and the selected phase rotation factor, and

control the transmitter to transmit the preamble into which the sequence is inserted to a station (STA),

wherein the selected phase rotation factor is applied in a unit of the basic sequence structure that is repeatedly included in the sequence once or more.

10. The AP according to claim 9, wherein the basic sequence structure is configured in the form of X₆C_48(1:

24)A₅C<sub>48(25;

48)</sub>X₅, the C<sub>48(1;

24)</sub> indicates first to 24^th tones of the C₄₈, the C<sub>48(25;

48)</sub> indicates 25^th to 48^th tones of the C₄₈, and the 0₅ indicates five consecutive 0.

11. The AP according to claim 9, wherein the X₆ is configured in the form of [0, 0, 0, 0, X1, 0] and the X₅ is configured in the form of [0, X2, 0, 0, 0].

12. The AP according to claim 11, wherein the X1 and the X2 satisfy

13. The AP according to claim 9, wherein the basic sequence structure is configured in the form of X₆C_48(1:

24)A₅C<sub>48(25;

48)</sub>X₅, the C<sub>48(1;

24)</sub> indicates first to 24^th tones of the C₄₈, the C<sub>48(25;

48)</sub> indicates 25^th to 48^th tones of the C₄, and the A₅ comprises 5 tones and comprises one non-zero value in a central part.

14. The AP according to claim 9,

wherein the processor is further configured to:

generate the sequence by repeating the basic sequence structure once when the bandwidth corresponds to 20 MHz;

generate the sequence by repeating the basic sequence structure twice and by using two corresponding phase rotation values when the bandwidth corresponds to 40 MHz; and

generate the sequence by repeating the basic sequence structure four times and using four corresponding phase rotation values when the bandwidth corresponds to 80 MHz.

15. The AP according to claim 9,

wherein the processor is further configured to:

generate the sequence by repeating the basic sequence structure once when the bandwidth corresponds to 20 MHz;

generate the sequence by repeating a new sequence, in which the X5 and the X6 are removed from the basic sequence structure, twice and by using two corresponding phase rotation values, A11, X5, and X6 when bandwidth corresponds to 40 MHz; and

generate the sequence by repeating the new sequence, in which the X5 and the X6 are removed from the basic sequence structure, and by using two corresponding phase rotation values when the bandwidth corresponds to 80 MHz.

16. The AP according to claim 15, wherein the A₁₁ is configured in the form of [0, A2, 0, 0, 0, A3, 0, 0, 0, A4, 0] and the A2, A3, and A4 are complex numbers that are not 0.