METHOD AND APPARATUS OF GENERATING PILOT SEQUENCE

• US 20140286455A1
• Filed: 10/12/2012
• Published: 09/25/2014
• Est. Priority Date: 02/15/2012
• Status: Active Grant

• Current Assignee: LG Electronics, Inc. (LG Corporation)
• Original Assignee: LG Electronics, Inc. (LG Corporation)
• Inventors: Choi, Jin Soo, Han, Seung Hee, Kwak, Jin Sam, Kim, Jeong Ki, Seuk, Yong Ho
• Granted Patent: US 9,014,286 B2
• Time in Patent Office: Days
• US Class Current: 375/308
• CPC Class Codes: H04L 27/2603 Signal structure ensuring backward compatibility with legacy system
• CPC Class Codes: H04L 27/2613 Structure of the reference signals
• CPC Class Codes: H04L 5/0007 the frequencies being orthogonal, e.g. OFDM(A), DMT
• CPC Class Codes: H04L 5/0048 Allocation of pilot signals, i.e. of signals known to the receiver

Abstract

A method of transmitting pilots id disclosed. The method of transmitting pilots includes transmitting pilots over N orthogonal frequency division multiplexing (OFDM) symbols, wherein a pilot at subcarrier k for OFDM symbol n is determined to have time varying characteristic, thereby to prevent the cause of spectral lines.

Claims

1. A method of transmitting pilots, the method comprising:

transmitting pilots over N orthogonal frequency division multiplexing (OFDM) symbols,

wherein a pilot P_n^k at subcarrier k for OFDM symbol n is determined by;

P_n<sup>k=−

7</sup>=Ψ

<sub>(n mod

     2)+2</sub>,P_n^k=7=Ψ

<sub>((n+1) mod

     2)+2</sub>,P_n<sup>k∉

{−

7,7}</sup>=0

wherein a OFDM symbol index n=0, . . . , N −

1, pilot values Ψ

₂=1 and Ψ

₃=−

1.

2. The method of claim 1, wherein a bandwidth of the transmitted pilots is 1 MHz.

3. The method of claim 1, wherein k is an integer in the range −

K≦

k≦

K(k≠

0), and K is an integer in the range 7≦

K≦

28.

4. The method of claim 1, further comprising:

selecting a transmission bandwidth;

determining predetermined pilot values in a pilot value mapping table according to a range of the transmission bandwidth; and

inserting the predetermined pilot values over N orthogonal frequency division multiplexing (OFDM) symbols,

wherein the predetermined pilot values are {Ψ

₂, Ψ

₃} in the pilot value mapping table when the range of the transmission bandwidth is 1 MHz; and

wherein the pilot value mapping table is specified as below

5. The method of claim 1, wherein the pilots are binary phase shift keying(BPSK) modulated by pseudo-binary sequence.

6. The method of claim 1, wherein the step of transmitting the pilots over N OFDM symbols includes:

transmitting first pilots for a first spatial stream;

copying a mapping of the first pilots to a mapping of a second pilots of a second spatial stream; and

transmitting the second pilots of the second spatial stream.

7. A wireless device configured to transmit control signals in a wireless communication system, the wireless device comprising a processor configured to:

transmit pilots over N orthogonal frequency division multiplexing (OFDM) symbols,

wherein a pilot P_n^k at subcarrier k for OFDM symbol n is determined by;

P_n<sup>k=−

7</sup>=Ψ

<sub>(n mod

     2)+2</sub>,P_n^k=7=Ψ

<sub>((n+1) mod

     2)+2</sub>,P_n<sup>k∉

{−

7,7}</sup>=0

wherein a OFDM symbol index, n=0, . . . , N −

1, pilot values Ψ

₂=1 and Ψ

₃=−

1.

8. The wireless device of claim 7, wherein a bandwidth of the transmitted pilots is 1 MHz.

9. The wireless device of claim 7, wherein k is an integer in the range −

K≦

k≦

K(k≠

0), and K is an integer in the range 7≦

K≦

28.

10. The wireless device of claim 7, wherein the processor is further configured to transmit pilots over N orthogonal frequency division multiplexing (OFDM) symbols by:

selecting a transmission bandwidth;

determining predetermined pilot values in a pilot value mapping table according to a range of the transmission bandwidth; and

inserting the predetermined pilot values over N orthogonal frequency division multiplexing (OFDM) symbols,

wherein the predetermined pilot values are {Ψ

₂, Ψ

₃} in the pilot value mapping table when the range of the transmission bandwidth is 1 MHz; and

wherein the pilot value mapping table is specified as below

11. The wireless device of claim 7, wherein the pilots are binary phase shift keying(BPSK) modulated by pseudo-binary sequence.

12. The wireless device of claim 7, wherein the step of transmitting the pilots over N OFDM symbols includes:

transmitting first pilots for a first spatial stream;

copying a mapping of the first pilots to a mapping of a second pilots of a second spatial stream; and

transmitting the second pilots of the second spatial stream.