Pilot Signal Determination Method and Wireless Communication System Using the Same

• US 20110176626A1
• Filed: 12/13/2010
• Published: 07/21/2011
• Est. Priority Date: 01/19/2010
• Status: Abandoned Application

• Current Assignee: Ralink Technology Corporation (MediaTek, Inc.)
• Original Assignee: Ralink Technology Corporation (MediaTek, Inc.)
• Inventors: Wu, Cheng-Hsuan, Liao, Yen-Chin, Tu, Yung-Szu
• Application Number:
  US12/967,014
• Publication Number:
  US 20110176626A1
• Time in Patent Office: Days
• US Class Current: 375/260
• CPC Class Codes: H04L 27/2613 Structure of the reference signals
• CPC Class Codes: H04L 5/0023 Time-frequency-space
• CPC Class Codes: H04L 5/0051 of dedicated pilots, i.e. pilots destined for a single user or terminal

Abstract

The present invention disclose a pilot signal determination method for a wireless communication system. The wireless communication system utilizes a plurality of sub-carriers. The pilot signal determination method includes steps of generating at least one vector corresponding to at least one sub-channel; and determining a plurality of pilot signals according to the at least one vector.

Claims

1. A pilot signal determination method for a wireless communication system, the wireless communication system utilizing a plurality of sub-carriers, the pilot signal determination method comprising:

generating at least one vector corresponding to at least one sub-channel; and

determining a plurality of pilot signals according to the at least one vector.

2. The pilot signal determination method of claim 1, wherein the at least one vector is expressed as:

φ

^(s)=[φ

₀^(s) φ

₁^(s) φ

₂^(s) φ

₃^(s)],

wherein s denotes an s-th sub-channel of the at least one sub-channel, and φ

_i^(s)={0,1} for i=0, 1, 2, 3.

3. The pilot signal determination method of claim 2, wherein generating the at least one vector corresponding to the at least one sub-channel comprises:

setting a plurality of values of the φ

_i^(s).

4. The pilot signal determination method of claim 2, wherein determining the plurality of pilot signals according to the at least one vector comprises:

summing a plurality of values of the φ

_i^(s) as an amount of a plurality of pilot signals for one space time stream, which can be expressed as;

5. The pilot signal determination method of claim 2, wherein determining the plurality of pilot signals according to the at least one vector comprises:

determining a plurality of pilot locations of the plurality of pilot signals according the at least one vector and a predefined vector.

6. The pilot signal determination method of claim 5, wherein the predefined vector comprises a plurality of elements, and a plurality of values of the plurality of elements are separated by a specific value in between.

7. The pilot signal determination method of claim 5, wherein determining the plurality of pilot locations of the plurality of pilot signals according the at least one vector and the predefined vector comprises:

determining the plurality of pilot locations of the plurality of pilot signals according to a formula, which can be expressed as;

8. The pilot signal determination method of claim 7, wherein the predefined vector is [11 25 39 53].

9. The pilot signal determination method of claim 8, wherein the wireless communication system is a 20 MHz system and the at least one vector is φ

⁽⁰⁾=[1 1 1 1].

10. The pilot signal determination method of claim 8, wherein the wireless communication system is a 40 MHz system and the at least one vector is φ

⁽⁰⁾=[1 0 1 1], φ

⁽¹⁾=[1 1 0 1].

11. The pilot signal determination method of claim 8, wherein the wireless communication system is an 80 MHz bandwidth system and the at least one vector is φ

⁽⁰⁾=[0 1 0 1], φ

⁽¹⁾=[0 1 0 1], φ

⁽²⁾=[1 0 1 0], φ

⁽³⁾=[1 0 1 0].

12. The pilot signal determination method of claim 11, wherein the plurality of pilot locations are −

103, −

75, −

39, −

11, 11, 39, 75 and 103.

13. The pilot signal determination method of claim 8, wherein the wireless communication system is an 80 MHz system and the at least one vector is φ

⁽⁰⁾=[1 0 1 0], φ

⁽¹⁾=[1 0 1 0], φ

⁽²⁾=[0 1 0 1], φ

⁽³⁾=[0 1 0 1].

14. The pilot signal determination method of claim 13, wherein the plurality of pilot locations are −

117, −

89, −

53, −

25, 25, 53, 89 and 117.

15. The pilot signal determination method of claim 1, wherein the at least one vector for an Orthogonal frequency-division multiplexing (OFDM) symbol is different from other at least one vector for another OFDM symbol.

16. The pilot signal determination method of claim 1, wherein the at least one vector is for even OFDM symbols, and are different from other at least one vector for odd OFDM symbols.

17. The pilot signal determination method of claim 1, wherein determining the plurality of pilot signals according to the at least one vector comprises:

determining a plurality of pilot values of the plurality of pilot signals.

18. The pilot signal determination method of claim 17, wherein determining the plurality of pilot values of the plurality of pilot signals comprises:

generating a plurality of sequences orthogonal to each other, each comprising a plurality of elements;

assigning each of the plurality of pilot signals with one distinct sequence of the plurality of sequences; and

assigning the pilot values of each of the plurality of pilot signals with the plurality of elements of the one distinct sequence in a first specific order.

19. The pilot signal determination method of claim 17, wherein the first specific order is that the pilot value of each of the plurality of pilot signals for an n-th OFDM symbol is assigned with an (n⊕

U)-th element of the one distinct sequence.

20. The pilot signal determination method of claim 17, wherein determining the plurality of pilot values of the plurality of pilot signals comprises:

generating an N_STS-by-L matrix; and

assigning the pilot values of the plurality of pilot signals with a plurality of elements of the N_STS-by-L matrix in a second specific order.

wherein N_STS denotes an amount of a plurality of space time streams, L denotes an amount of a plurality of pilot signals for one space time stream, and QQ^T=I_NSTS, where Q denotes the N_STS-by-L matrix.

21. The pilot signal determination method of claim 17, wherein the second specific order is that the pilot value of an ((1+n)⊕

L)-th pilot signal on an i_STS-th space-time stream for an n-th OFDM symbol is assigned with an (i_STS,

     1) element of the N_STS-by-L matrix.

22. A wireless communication system utilizing a plurality of sub-carriers, comprising:

a microprocessor; and

a memory, for storing a program, for instructing the microprocessor to execute the pilot signal determination method of claim 1.