I/Q modulator with carrier predistortion

US7305046B2 · kind B2 · utility

Assignee

• Fraunhofer-Gesellschaft zur förderung der angewandten Forschung e.V. · DE

Inventors

• Eberhard Gamm · Ebermannstadt, DE
• Reiner Retkowski · Erlangen, DE
• Gerald Ulbricht · Westerburg, DE
• Heinz Gerhaeuser · Erlangen, DE

Key dates

• Filing date: Mar 2, 2001
• Grant date: Dec 4, 2007
• Expiry date: Sep 19, 2023

Classification

• Technology area (CPC H): Electricity
• CPC primary: H04L27/368
• WIPO field: Digital communication
• WIPO sector: Electrical engineering

Abstract

An I/Q modulator used for processing an I/Q signal to obtain a predistorted output signal. The I/Q signal has an I component and a Q component, and comprises a predistorter for predistorting, with a predistortion signal, a carrier signal, which comprises a first subcomponent and a second subcomponent that is substantially orthogonal to the first subcomponent, to obtain first and second predistorted subcomponents of the carrier signal. The predistortion signal depends on the I and Q components. A first multiplier multiples the I component by the first predistorted subcomponent to obtain a multiplied I component. A second multiplier multiples the Q component by the second predistorted subcomponent to obtain a multiplied Q component. An adder adds the multiplied I component and the negative multiplied Q component to obtain the predistorted output signal. Thus, a simplification of the I/Q modulator and a reduction in the number of necessary multipliers is achieved.