System and Method for Reducing Peak-To-Average Power Ratio For Multi-Carrier Communication Systems

• US 20120114074A1
• Filed: 01/17/2012
• Published: 05/10/2012
• Est. Priority Date: 10/23/2003
• Status: Active Grant

• Current Assignee: Smartsky Networks Llc
• Original Assignee: Harris Corporation (L3Harris Technologies, Inc.)
• Inventors: Moffatt, Christopher Douglas, Kolar, Ray J., Richards, Charles W.
• Granted Patent: US 8,442,137 B2
• Time in Patent Office: Days
• US Class Current: 375/296
• CPC Class Codes: H04L 27/2614 Peak power aspects

Abstract

The present disclosure presents a predictive signal producing method that effectively levels transmitter output power in a multi-carrier communication system and results in approaching amplifier performance normally associated with constant carrier waveforms. Embodiments of the disclosed solution offers >10 dB reduction in the peak-to-average power required to support the transmission of, for example, orthogonal frequency division modulation (“OFDM”) modulation techniques. Embodiments of the novel system and method maximize peak-to-average power ratio (“PAPR”) reduction with selective mapping and soft clipping, which may include filtering, combined. This novel approach also minimizes overhead, bit error rate, retransmissions, and increases latency as well as implementing processing cycles with a number of iterations. The disclosed system and method improves the total system DC power efficiency and provides an optimal solution for PAPR reduction in multi-carrier communication systems such as, for example, OFDM.

Claims

1. In a multi-carrier communication system, a transmitter for transmitting data with multiple carriers, comprising:

a modulator for modulating multi-carrier symbols with the data thereby creating one or more modulated signals;

a processor for measuring a peak-to-average power ratio of the modulated signals;

a logic device for comparing the peak-to-average power ratio of the modulated signals with a predetermined threshold and for selecting a modulated signal based on the comparison;

a processor for appending a data map signal associated with the selected signal to create re-sequenced signal; and

an amplitude filter for reducing peaks of the re-sequenced signal that are outside a predetermined range.

2. The system of claim 1 wherein the amplitude filter is a FIR filter.

3. The system of claim 1 wherein the amplitude filter is an IIR filter.