METHOD AND APPARATUS FOR PEAK TO AVERAGE POWER REDUCTION IN WIRELESS COMMUNICATION SYSTEMS USING SPECTRAL MASK FILLING

• US 20160020933A1
• Filed: 03/31/2015
• Published: 01/21/2016
• Est. Priority Date: 07/18/2014
• Status: Active Grant

• Current Assignee: Samsung Electronics Co. Ltd.
• Original Assignee: Samsung Electronics Co. Ltd.
• Inventors: Rajagopal, Sridhar, Abu-Surra, Shadi
• Granted Patent: US 10,050,816 B2
• Time in Patent Office: Days
• US Class Current: 1/1
• CPC Class Codes: H04L 27/0006 Assessment of spectral gaps suitable for allocating digitally modulated signals, e.g. for carrier allocation in cognitive radio for spectrum sharing between different networks H04W16/14

Abstract

A user equipment, apparatus, and method are provided for wireless communication with at least one base station. The user equipment includes a transceiver configured to communicate with the at least one base station by transmitting radio frequency signals to the at least one base station and by receiving radio frequency signals from the at least one base station. The user equipment also includes processing circuitry. The processing circuitry is configured to identify an occupied signal bandwidth of the radio frequency signals. The processing circuitry is also configured to identify a spectral mask for the occupied signal bandwidth. The processing circuitry is also configured to identify an unused available spectrum between the occupied signal bandwidth and the spectral mask. The processing circuitry is also configured to modulate a spectral mask filling (SMF) signal in the unused available spectrum, the SMF signal configured to reduce the peak-to-average power ratio of the radio frequency signals.

Claims

1. A user equipment for wireless communication with at least one base station comprising:

a transceiver configured to communicate with the at least one base station by transmitting radio frequency signals to the at least one base station and by receiving radio frequency signals from the at least one base station; and

processing circuitry configured to;

identify an occupied signal bandwidth of the radio frequency signals;

identify a spectral mask for the occupied signal bandwidth

identify an unused available spectrum between the occupied signal bandwidth and the spectral mask; and

modulate a spectral mask filling (SMF) signal in the unused available spectrum, the SMF signal configured to reduce the peak-to-average power ratio of the radio frequency signals.

2. The user equipment of claim 1, wherein modulating the SMF signal in the unused available spectrum further comprises the processing circuitry configured to modulate the SMF signal in a time domain, where the SMF signal is derived using a SMF sequence in a frequency domain.

3. The user equipment of claim 2, wherein the SMF sequence in the frequency domain is defined as:

4. The user equipment of claim 2, wherein the SMF sequence in the frequency domain is defined as:

5. The user equipment of claim 1, wherein modulating the SMF signal in the unused available spectrum further comprises the processing circuitry configured to align a peak of the RF signals to a peak of the SMF signal by circularly shifting the frequency domain sequence of the SMF signal.

6. The user equipment of claim 5, wherein circularly shifting the sequence further comprises the processing circuitry configured to iteratively circularly shift the sequence to cancel a plurality of peaks of the RF signals.

7. The user equipment of claim 6, wherein iteratively circularly shifting the sequence to cancel the plurality of peaks of the RF signals further comprises the processing circuitry configured in a feed forward architecture.

8. The user equipment of claim 6, wherein the processing circuitry is further configured to approximate a plurality of peaks of the RF signals before canceling the plurality of peaks, wherein the approximation comprises a calculation with an assumption that the plurality of peaks of the RF signals do not change with each iteration of circular shifting.

9. The user equipment of claim 1, further comprising a plurality of RF chains, each RF chain comprising an RF stream, wherein the processing circuitry is further configured to modulate the spectral mask filling (SMF) signal in the unused available spectrum independently on each of the RF streams with appropriate scaling levels relative to a signal power applied for each of the RF streams.

17. The apparatus of claim 6, wherein the controller is further configured to approximate a plurality of peaks of the RF signals before canceling the plurality of peaks, wherein the approximation comprises a calculation with an assumption that the plurality of peaks of the RF signals do not change with each iteration of circular shifting.

10. An apparatus comprising:

a memory element configured to store radio frequency signals; and

a controller coupled to the memory element, the controller configured to;

identify an occupied signal bandwidth of the radio frequency signals;

identify a spectral mask for the occupied signal bandwidth

identify an unused available spectrum between the occupied signal bandwidth and the spectral mask; and

modulate a spectral mask filling (SMF) signal in the unused available spectrum, the SMF signal configured to reduce the peak-to-average power ratio of the radio frequency signals.

11. The apparatus of claim 10, wherein modulating the SMF signal in the unused available spectrum further comprises the controller configured to modulate the SMF signal in a time domain, where the SMF signal is derived using a SMF sequence in a frequency domain.

12. The apparatus of claim 11, wherein the SMF sequence in the frequency domain is defined as:

13. The user equipment of claim 11, wherein the SMF sequence in the frequency domain is defined as:

14. The apparatus of claim 10, wherein modulating the SMF signal in the unused available spectrum further comprises the controller configured to align a peak of the RF signals to a peak of the SMF signal by circularly shifting the frequency domain sequence of the SMF signal.

15. The apparatus of claim 14, wherein circularly shifting the sequence further comprises the controller configured to iteratively circularly shift the sequence to cancel a plurality of peaks of the RF signals.

16. The apparatus of claim 15, wherein iteratively circularly shifting the sequence to cancel the plurality of peaks of the RF signals further comprises the controller configured in a feed forward architecture.

18. The apparatus of claim 10, further comprising a plurality of RF chains, each RF chain comprising an RF stream, wherein the controller is further configured to modulate the spectral mask filling (SMF) signal in the unused available spectrum independently on each of the RF streams with appropriate scaling levels relative to a signal power applied for each of the RF streams.

19. A method for peak to average peak ratio reduction, the method comprising:

identifying an occupied signal bandwidth of the radio frequency signals;

identifying a spectral mask for the occupied signal bandwidth

identifying an unused available spectrum between the occupied signal bandwidth and the spectral mask; and

modulating a spectral mask filling (SMF) signal in the unused available spectrum, the SMF signal configured to reduce the peak-to-average power ratio of the radio frequency signals.

20. The method of claim 19, wherein modulating the SMF signal in the unused available spectrum further comprises modulating the SMF signal in a time domain, where the SMF signal is derived using a SMF sequence in a frequency domain.