Apparatus and method for reducing the peak-to-average power ratio of OFDM/OFDMA signals

• US 20060140296A1
• Filed: 11/22/2005
• Published: 06/29/2006
• Est. Priority Date: 12/14/2001
• Status: Active Grant

• Current Assignee: Samsung Electronics Co. Ltd.
• Original Assignee: Samsung Electronics Co. Ltd.
• Inventors: Cleveland, Joseph R., Trivedi, Akshaya A.
• Granted Patent: US 7,224,742 B2
• Time in Patent Office: Days
• US Class Current: 375/260
• CPC Class Codes: H04L 27/2618 Reduction thereof using auxiliary subcarriers

Abstract

An apparatus is provided for reducing the peak-to-average power ratio (PAPR) of a multicarrier transmission system. The apparatus comprises a detector for receiving a plurality of symbols to be transmitted and determining a peak amplitude of the plurality of symbols and a controller for determining if the peak amplitude associated with the plurality of symbols exceeds a predetermined threshold. If the peak amplitude exceeds the predetermined threshold, the apparatus generates at least one correction carrier signal. The at least one correction carrier signal is combined with a plurality of modulated carrier signals associated with the plurality of symbols to thereby reduce a peak-to-average power ratio associated with the plurality of modulated carrier signals.

Claims

1. An apparatus for reducing the peak-to-average power ratio (PAPR) of a multicarrier transmission system comprising:

a detector for receiving a plurality of symbols to be transmitted and determining a peak amplitude of the plurality of symbols;

a controller for determining if the peak amplitude associated with the plurality of symbols exceeds a predetermined threshold and, in response to a determination that the peak amplitude exceeds the predetermined threshold, generating at least one correction pulse; and

a PAPR reduction block for generating at least one correction carrier signal from the at least one correction pulse, wherein the at least one correction carrier signal is combined with a plurality of modulated carrier signals associated with the plurality of symbols to thereby reduce a peak-to-average power ratio associated with the plurality of modulated carrier signals.

2. The apparatus as set forth in claim 1, wherein the plurality of modulated carrier signals comprises one of:

orthogonal frequency division multiplexing (OFDM) signals and orthogonal frequency division multiple access (OFDMA) signals.

3. The apparatus as set forth in claim 1, wherein the plurality of symbols to be transmitted comprises a plurality of in-phase symbols and a plurality of quadrature symbols.

4. The apparatus as set forth in claim 3, wherein the at least one correction pulse comprises an in-phase correction pulse generated from the plurality of in-phase symbols and a quadrature pulse generated from the plurality of quadrature symbols.

5. The apparatus as set forth in claim 3, wherein the at least one correction pulse comprises a single correction pulse generated from the plurality of in-phase symbols and the plurality of quadrature symbols.

6. The apparatus as set forth in claim 1, wherein the apparatus is implemented in a mobile terminal capable of communicating with base stations of a wireless network.

7. The apparatus as set forth in claim 1, wherein the apparatus is implemented in a base station of a wireless network.

8. A wireless network base station comprising:

a transmitter capable of transmitting multicarrier signals to subscriber stations in a wireless network; and

an apparatus associated with the transmitter for reducing the peak-to-average power ratio (PAPR) of the multicarrier signals, the apparatus comprising;

a detector for receiving a plurality of symbols to be transmitted and determining a peak amplitude of the plurality of symbols;

a controller for determining if the peak amplitude associated with the plurality of symbols exceeds a predetermined threshold and, in response to a determination that the peak amplitude exceeds the predetermined threshold, generating at least one correction pulse; and

a PAPR reduction block for generating at least one correction carrier signal from the at least one correction pulse, wherein the at least one correction carrier signal is combined with a plurality of modulated carrier signals associated with the plurality of symbols to thereby reduce a peak-to-average power ratio associated with the plurality of modulated carrier signals.

9. The wireless network base station as set forth in claim 8, wherein the plurality of modulated carrier signals comprises one of:

orthogonal frequency division multiplexing (OFDM) signals and orthogonal frequency division multiple access (OFDMA) signals.

10. The wireless network base station as set forth in claim 8, wherein the plurality of symbols to be transmitted comprises a plurality of in-phase symbols and a plurality of quadrature symbols.

11. The wireless network base station as set forth in claim 10, wherein the at least one correction pulse comprises an in-phase correction pulse generated from the plurality of in-phase symbols and a quadrature pulse generated from the plurality of quadrature symbols.

12. The wireless network base station as set forth in claim 10, wherein the at least one correction pulse comprises a single correction pulse generated from the plurality of in-phase symbols and the plurality of quadrature symbols.

13. A subscriber station capable of communicating with a wireless network, the subscriber station comprising:

a transmitter capable of transmitting multicarrier signals to the wireless network; and

an apparatus associated with the transmitter for reducing the peak-to-average power ratio (PAPR) of the multicarrier signals, the apparatus comprising;

a detector for receiving a plurality of symbols to be transmitted and determining a peak amplitude of the plurality of symbols;

a controller for determining if the peak amplitude associated with the plurality of symbols exceeds a predetermined threshold and, in response to a determination that the peak amplitude exceeds the predetermined threshold, generating at least one correction pulse; and

a PAPR reduction block for generating at least one correction carrier signal from the at least one correction pulse, wherein the at least one correction carrier signal is combined with a plurality of modulated carrier signals associated with the plurality of symbols to thereby reduce a peak-to-average power ratio associated with the plurality of modulated carrier signals.

14. The subscriber station as set forth in claim 13, wherein the plurality of modulated carrier signals comprises one of:

orthogonal frequency division multiplexing (OFDM) signals and orthogonal frequency division multiple access (OFDMA) signals.

15. The subscriber station as set forth in claim 13, wherein the plurality of symbols to be transmitted comprises a plurality of in-phase symbols and a plurality of quadrature symbols.

16. The subscriber station as set forth in claim 15, wherein the at least one correction pulse comprises an in-phase correction pulse generated from the plurality of in-phase symbols and a quadrature pulse generated from the plurality of quadrature symbols.

17. The subscriber station as set forth in claim 15, wherein the at least one correction pulse comprises a single correction pulse generated from the plurality of in-phase symbols and the plurality of quadrature symbols.

18. A method for reducing the peak-to-average power ratio (PAPR) of a multicarrier transmission system, the method comprising the steps of:

receiving a plurality of symbols to be transmitted;

determining a peak amplitude of the plurality of symbols;

determining if the peak amplitude associated with the plurality of symbols exceeds a predetermined threshold;

in response to a determination that the peak amplitude exceeds the predetermined threshold, generating at least one correction pulse;

generating at least one correction carrier signal from the at least one correction pulse; and

combining the at least one correction carrier signal with a plurality of modulated carrier signals associated with the plurality of symbols to thereby reduce a peak-to-average power ratio associated with the plurality of modulated carrier signals.

19. The method as set forth in claim 18, wherein the plurality of modulated carrier signals comprises one of:

orthogonal frequency division multiplexing (OFDM) signals and orthogonal frequency division multiple access (OFDMA) signals.

20. The method as set forth in claim 18, wherein the plurality of symbols to be transmitted comprises a plurality of in-phase symbols and a plurality of quadrature symbols.

21. The method as set forth in claim 20, wherein the at least one correction pulse comprises an in-phase correction pulse generated from the plurality of in-phase symbols and a quadrature pulse generated from the plurality of quadrature symbols.

22. The method as set forth in claim 20, wherein the at least one correction pulse comprises a single correction pulse generated from the plurality of in-phase symbols and the plurality of quadrature symbols.

23. The method as set forth in claim 18, wherein the method is implemented in a mobile terminal capable of communicating with base stations of a wireless network.

24. The method as set forth in claim 18, wherein the method is implemented in a base station of a wireless network.

25. An apparatus for reducing the peak-to-average power ratio (PAPR) of a multicarrier transmission system comprising:

a detector for receiving a plurality of symbols to be transmitted and determining a peak amplitude of the plurality of symbols;

a controller for determining if the peak amplitude associated with the plurality of symbols exceeds a predetermined threshold and, in response to a determination that the peak amplitude exceeds the predetermined threshold, generating at least one correction carrier signal,

wherein the at least one correction carrier signal is combined with a plurality of modulated carrier signals associated with the plurality of symbols to thereby reduce a peak-to-average power ratio associated with the plurality of modulated carrier signals.

26. The apparatus as set forth in claim 25, wherein the plurality of modulated carrier signals comprises one of:

orthogonal frequency division multiplexing (OFDM) signals and orthogonal frequency division multiple access (OFDMA) signals.

27. The apparatus as set forth in claim 25, wherein the plurality of symbols to be transmitted comprises a plurality of in-phase symbols and a plurality of quadrature symbols.

28. The apparatus as set forth in claim 27, wherein the at least one correction carrier signal comprises a first correction carrier signal generated from the plurality of in-phase symbols and a second correction carrier signal generated from the plurality of quadrature symbols.

29. The apparatus as set forth in claim 27, wherein the at least one correction carrier signal is generated from the plurality of in-phase symbols and the plurality of quadrature symbols.