Signal splitting method for limiting peak power in a CDMA system

• US 7,965,688 B2
• Filed: 06/26/2007
• Issued: 06/21/2011
• Est. Priority Date: 08/31/1998
• Status: Expired due to Term

• Current Assignee: Qualcomm, Inc.
• Original Assignee: Qualcomm, Inc.
• Inventors: Lundby, Stein A., Terasawa, Daisuke, Tiedemann, Edward G. Jr., Holtzman, Jack M.
• Primary Examiner(s): Sheikh; Ayaz R
• Assistant Examiner(s): LEE, ANDREW CHUNG CHEUNG
• Application Number:
  US11/768,863
• Publication Number:
  US 20080013494A1
• Time in Patent Office: 1,456 Days
• Field of Search: 370/208, 370/280, 370/311, 370/316, 370/317, 370/318, 370/332, 370/333, 370/335, 370/337, 370/342, 370/348, 454/69, 454/126, 454/127, 454/452.1
• US Class Current: 370/335
• CPC Class Codes: H04B 1/707 using direct sequence modulation
• CPC Class Codes: H04B 2201/70706 with means for reducing the peak-to-average power ratio
• CPC Class Codes: H04B 2201/709709 Methods of preventing interference
• CPC Class Codes: H04W 52/36 with a discrete range or set of values, e.g. step size, ramping or offsets

Abstract

The invention is a method for limiting the peak transmit power in a CDMA communication system. At least one of first and second high transmit power regions are separated into a plurality of high transmit power subregions. The high transmit power subregions of the plurality of high subregions are shifted by time offsets of differing durations to provide a plurality of time offset subregions. First and second low transmit power regions are also provided. At least one of the first and second low transmit power regions is also separated into a plurality of transmit power subregions and the low transmit power subregions are shifted by time offsets of differing time durations. The subregions can be time offset by a predetermined time duration or by a random time duration.

Claims

1. A method for limiting peak transmit power in a wireless communication system, comprising:

using a transmitter for providing a plurality of transmit waveforms, wherein each transmit waveform, of the plurality of transmit waveforms, comprises a plurality of portions;

selecting a non-fixed individual time offset for each of the plurality of transmit waveforms according to an algorithm; and

delaying transmission of each transmit waveform, of the plurality of transmit waveforms, by its corresponding non-fixed individual time offset, wherein the plurality of portions of each transmit waveform is transmitted in a sequence to limit peak transmit power.

2. The method for limiting peak transmit power of claim 1, wherein the algorithm comprises selecting a non-fixed individual time offset by determining which of a possible set of offsets is being used by a lowest number of the plurality of transmit waveforms.

3. The method for limiting peak transmit power of claim 1, wherein the algorithm comprises a peak power algorithm that provides a minimum increase in the peak transmit power according to the shape or expected shape of each transmit waveform of the plurality of transmit waveforms.

4. The method for limiting peak transmit power of claim 1, wherein the algorithm comprises a heuristic algorithm.

5. A system for limiting peak transmit power in a wireless communication system, comprising:

means for providing a plurality of transmit waveforms, wherein each transmit waveform, of the plurality of transmit waveforms, comprises a plurality of portions;

means for selecting a non-fixed individual time offset for each of the plurality of transmit waveforms according to an algorithm; and

means for delaying transmission of each transmit waveform, of the plurality of transmit waveforms, by its corresponding non-fixed individual time offset, wherein the plurality of portions of each transmit waveform is transmitted in a sequence to limit peak transmit power.

6. The system for limiting peak transmit power of claim 5, wherein the means for selecting a non-fixed individual time offset for each transmit waveform of the plurality of transmit waveforms according to an algorithm comprises a means for selecting a non-fixed individual time offset by determining which of a possible set of offsets is being used by a lowest number of the plurality of transmit waveforms.

7. The system for limiting peak transmit power of claim 5, wherein the means for selecting a non-fixed individual time offset for each transmit waveform of the plurality of transmit waveforms according to an algorithm comprises a means for a peak power algorithm to provide a minimum increase in the peak transmit power according to the shape or expected shape of each of the plurality of transmit waveforms.

8. The system for limiting peak transmit power of claim 5, wherein the means for selecting a non-fixed individual time offset for each transmit waveform of the plurality of transmit waveforms according to an algorithm comprises a means for performing a heuristic algorithm.