Method and apparatus for generating pilot tone in orthogonal frequency division multiplexing access system, and method and apparatus for estimating channel using it

Patent metadata

Field	Value
Publication number	US-9276719-B2
Application number	US-201314065976-A
Country	US
Kind code	B2
Filing date	Oct 29, 2013
Priority date	Dec 27, 2006
Publication date	Mar 1, 2016
Grant date	Mar 1, 2016

Abstract

The present invention relates to a pilot tone generating method and apparatus of an orthogonal frequency division multiple access system and method, and a channel estimation method and apparatus using the same. The channel estimation apparatus includes a pilot tone extracting unit for extracting a pilot tone, which is inserted within a frame with data tone, masked with an orthogonal code; a pilot tone unmasking unit for unmasking of the pilot tone extracted from the pilot tone extracting unit by using an orthogonal code information; and a channel estimation operating unit for estimating a channel by calculating an average of the pilot tones which is unmasked in the unmasking unit.

First claim

The invention claimed is:

1. A method of receiving signals in a wireless communication system, comprising:
receiving from a transmitter a signal over at least one Orthogonal Frequency Division Multiplexing (OFDM) symbol from among a plurality of OFDM symbols, and a pilot over another at least one OFDM symbol from among the plurality of the OFDM symbols by using a resource block; and
demodulating the signal by using the pilot,
wherein the signal is generated by multiplying a modulation symbol with a sequence at the transmitter, the pilot is generated with an orthogonal sequence at the transmitter, and the resource block comprises a part of subcarriers in a frequency domain and the OFDM symbols in a time domain, respectively,
wherein the orthogonal sequence is determined from an orthogonal sequence set having a plurality of orthogonal sequences, and information used for determining the orthogonal sequence is provided by a downlink message.

2. The method of claim 1 , wherein the sequence is longer than the orthogonal sequence.

3. The method of claim 1 , wherein different cells are assigned different orthogonal sequences.

4. The method of claim 1 , wherein the sequence is a binary sequence.

5. The method of claim 1 , wherein the data is modulated with Binary Phase Shift Keying (BPSK) or Quadrature Phase Shift Keying (QPSK).

6. A receiver in a wireless communication system, comprising:
a receiving antenna for receiving from a transmitter a signal over at least one of Orthogonal Frequency Division Multiplexing (OFDM) symbol from among a plurality of OFDM symbols, and a pilot over another at least one OFDM symbol from among the plurality of the OFDM symbols by using a resource block; and
a demodulator for demodulating the signal by using the pilot,
wherein the signal is generated by multiplying a modulation symbol with a sequence at the transmitter, the pilot is generated with an orthogonal sequence at the transmitter, and the resource block comprises a part of subcarriers in a frequency domain and the OFDM symbols in a time domain, respectively,
wherein the orthogonal sequence is determined from an orthogonal sequence set having a plurality of orthogonal sequences and information used for determining the orthogonal sequence is provided by a downlink message.

7. The receiver of claim 6 , wherein the sequence is longer than the orthogonal sequence.

8. The receiver of claim 6 , wherein different cells are assigned different orthogonal sequences.

9. The receiver of claim 6 , wherein the sequence is a binary sequence.

10. The receiver of claim 6 , wherein the data is modulated with Binary Phase Shift Keying (BPSK) or Quadrature Phase Shift Keying (QPSK).

11. A method of receiving signals in a wireless communication system, comprising:
receiving from a transmitter a plurality of modulation symbols in a data region of a resource block and a plurality of pilot symbols in a pilot region of the resource block; and
demodulating, based on the plurality of pilot symbols, the plurality of modulation symbols to generate data,
wherein the resource block comprises a plurality of subcarriers in a frequency domain and a plurality of OFDM symbols in a time domain, respectively,
wherein the plurality of the pilot symbols are generated at the transmitter by multiplying pilots with an orthogonal sequence,
wherein at least one OFDM symbol among the plurality of OFDM symbols includes a part of the data region and a part of the pilot region in the resource block at the same time,
wherein the orthogonal sequence is of length 4 , and is determined from an orthogonal sequence set consisting of 4 orthogonal sequences [1, 1, 1, 1], [1, −1, 1, −1], [1, −1, −1, 1]and [1, 1, −1, −1], and
wherein information used for determining the orthogonal sequence is provided by a downlink message.

12. The method of claim 11 , wherein the data is scrambled by using a sequence at the transmitter.

13. The method of claim 12 , wherein the sequence is a random binary sequence.

14. The method of claim 11 , wherein the orthogonal sequence is determined from the orthogonal sequence set when the pilot symbols are positioned in the resource block specifically in relation with the orthogonal sequence set.

15. The method of claim 14 , wherein different users are assigned different orthogonal sequences.

16. The method of claim 11 , wherein the data is modulated with Binary Phase Shift Keying (BPSK) or Quadrature Phase Shift Keying (QPSK).

17. A receiver in a wireless communication system, wherein the receiver is configured for:
receiving from a transmitter a plurality of modulation symbols in a data region of a resource block and a plurality of pilot symbols in a pilot region of the resource block; and
demodulating, based on the plurality of pilot symbols, the plurality of modulation symbols to generate data,
wherein the resource block comprises a part of subcarriers in a frequency domain and a plurality of OFDM symbols in a time domain, respectively,
wherein the plurality of the pilot symbols are generated at the transmitter by multiplying pilots with an orthogonal sequence,
wherein at least one OFDM symbol among the plurality of OFDM symbols includes a part of the data region and a part of the pilot region in the resource block at the same time,
wherein the orthogonal sequence is of length 4 and is determined from an orthogonal sequence set consisting of 4 orthogonal sequences [1, 1, 1, 1], [1, −1, 1, −1], [1, −1, −1, 1] and [1, 1, −1, −1], and
wherein information used for determining the orthogonal sequence is provided by a downlink message.

18. The receiver of claim 17 , wherein the data is scrambled by using a sequence at the transmitter.

19. The receiver of claim 18 , wherein the sequence is a random binary sequence.

20. The receiver of claim 17 , wherein the orthogonal sequence is determined from the orthogonal sequence set when the pilot symbols are positioned in the resource block specifically in relation with the orthogonal sequence set.

21. The receiver of claim 20 , wherein different users are assigned different orthogonal sequences.

22. The receiver of claim 17 , wherein the data is modulated with Binary Phase Shift Keying (BPSK) or Quadrature Phase Shift Keying (QPSK).

Assignees

• Intellectual Discovery Co Ltd

Inventors

• Lee Dong-Kwan
• Kim Jung-Ju

Classifications

• H04J11/005

  of intercell interference · CPC title

• H04J13/004

  Orthogonal · CPC title

• H04L27/26134

  Pilot insertion in the transmitter chain, e.g. pilot overlapping with data, insertion in time or frequency domain · CPC title

• H04L25/0228

  with direct estimation from sounding signals · CPC title

• H04L5/0048 Primary

  Allocation of pilot signals, i.e. of signals known to the receiver (allocation of control signalling H04L5/0053; use of control signalling H04L5/0091) · CPC title