Efficient physical layer preamble format

• US 8,175,119 B2
• Filed: 05/15/2009
• Issued: 05/08/2012
• Est. Priority Date: 05/15/2008
• Status: Active Grant

• Current Assignee: NXP USA, Inc. (NXP Semiconductors NV)
• Original Assignee: Marvell World Trade Limited (Marvell Technology Group Limited)
• Inventors: Zhang, Hongyuan, Nabar, Rohit U., Wu, Songping, Lou, Hui-Ling
• Primary Examiner(s): Yao, Kwang B
• Assistant Examiner(s): NGO, NGUYEN HOANG
• Application Number:
  US12/467,010
• Publication Number:
  US 20090285241A1
• Time in Patent Office: 1,089 Days
• Field of Search: 370/476, 370/203, 370/328, 370/350, 370/464, 370/465, 370/471, 370/474
• US Class Current: 370/474
• CPC Class Codes: H04B 1/707 using direct sequence modulation
• CPC Class Codes: H04J 13/0014 Golay
• CPC Class Codes: H04J 13/10 Code generation
• CPC Class Codes: H04L 27/2613 Structure of the reference signals
• CPC Class Codes: H04L 27/26132 using repetition

Abstract

A method for generating a preamble of a data unit includes generating a short training field (STF) of the preamble to include one of a repeating series of a sequences or a repeating series of b sequences, such that a and b are complementary sequences, a sum of out-of-phase aperiodic autocorrelation coefficients of a and b is zero, and where the STF is associated with at least synchronization information, and generating a long training field (LTF) of the preamble after the STF to include a′ sequences and b′ sequences, such that a′ is the sequence a cyclically shifted by zero or more positions, b′ is the sequence b cyclically shifted by zero or more positions, and where the LTF is associated with channel estimation information.

Claims

1. A method for generating a preamble of a data unit, the method comprising:

generating a short training field (STF) of the preamble to include one of a repeating series of a sequences or a repeating series of b sequences;

wherein a and b are complementary sequences, wherein a sum of out-of-phase aperiodic autocorrelation coefficients of a and b is zero;

wherein the STF is associated with at least synchronization information;

generating a long training field (LTF) of the preamble after the STF to include a′

sequences and b′

sequences;

wherein a′

is the sequence a cyclically shifted by zero or more positions, and wherein b′

is the sequence b cyclically shifted by zero or more positions; and

wherein the LTF is associated with channel estimation information.

2. The method of claim 1, wherein the LTF is immediately after the STF and wherein a last sequence of the STF is a complementary sequence of the first sequence of the LTF.

3. The method of claim 2, wherein the LTF includes a CES symbol, wherein a beginning portion of the CES symbol occurs immediately after the STF, and wherein the last sequence of the STF serves as a cyclic prefix of the CES symbol.

4. The method of claim 1, wherein the LTF includes a first CES symbol and a second CES symbol, wherein the first CES symbol and the second CES symbol are complementary sequences.

5. The method of claim 4, wherein at least one of 1) an ending portion of the first CES symbol serves as a cyclic prefix of the second CES symbol, or 2) a beginning portion of the second CES symbol serves as a cyclic postfix of the first CES symbol.

6. The method of claim 1, further comprising:

applying a cover code to the STF to communicate a value of a physical layer parameter.

7. The method of claim 6, wherein the physical layer parameter is one of a piconet identity, an indication of a communication mode corresponding to one of a single carrier mode or an orthogonal frequency division multiplexing mode, or an indicator of a header rate.

8. The method of claim 1, further comprising generating a frame delimiter (FD) to indicate an end of the STF;

wherein the FD is after the STF and prior to the LTF.

9. The method of claim 8, further comprising indicating a value of a physical layer parameter using at least one of 1) an FD pattern or 2) a cover code of the STF.

10. The method of claim 8, further comprising indicating a value of a physical layer parameter using at least one of 1) an FD pattern or 2) selecting a or b to be included in the STF.