scispace - formally typeset
Patent

Compensation of filters in radio transmitters

Reads0
Chats0
TLDR
In this article, the transmit filter filters a signal to be transmitted from the transmitter to suppress the transmission of parts of the signal outside the band, where the compensating filter is arranged to alter the signal to counteract at least one of a phase ripple, an amplitude ripple, and a group delay variation of the transmitter within the band.
Abstract
A radio transmitter for transmitting signals in a predetermined frequency band has a transmit filter and a compensating filter. The transmit filter filters a signal to be transmitted from the transmitter to suppress the transmission of parts of the signal outside the band. The compensating filter, e.g., operating in the digital domain, filters the signal upstream from the transmit filter, wherein the compensating filter is arranged to alter the signal to counteract at least one of a phase ripple, an amplitude ripple, and a group delay variation of the transmit filter within the band.

read more

Citations
More filters
Patent

N-Way Doherty Distributed Power Amplifier with Power Tracking

TL;DR: In this paper, a power amplifier using N-way Doherty structure with adaptive bias supply power tracking for extending the efficiency region over the high peak-to-average power:ratio of the modulated signals such as wideband code division multiple access and orthogonal frequency division multiplexing is disclosed.
Patent

Systems and methods for spurious emission cancellation

TL;DR: In this paper, the authors proposed a method to digitally pre-distort a digital baseband signal with an opposite phase of a C-IM3 distortion term such that the predistortion and CIM3 distortions cancel each other out in a transmitter.
Patent

Multi-carrier receiver for wireless communication

TL;DR: In this paper, a multi-carrier receiver capable of receiving one or multiple frequency channels simultaneously is described, which includes a single radio frequency (RF) receive chain, an analog-to-digital converter (ADC), and at least one processor.
Patent

Method and system for baseband predistortion linearization in multi-channel wideband communication systems

TL;DR: An efficient baseband predistortion linearization method for reducing the spectral regrowth and compensating memory effects in wideband communication systems using effective multiple-xing modulation technique such as wideband code division multiple access and orthogonal frequency division multiplexing is disclosed in this paper.
PatentDOI

Baseband-derived rf digital predistortion

TL;DR: In this article, a baseband-derived RF predistortion system using a lookup table having coefficients extracted at baseband and then applied at RF by means of a vector modulator is described.
References
More filters
Patent

Polar modulation transmitter

TL;DR: In this paper, the driver amplifier circuit is implemented as differential transistor pairs responsive to tail current modulation, which is suited in particular for economical and space saving integration within a transmitter or transceiver integrated circuit (IC).
Patent

Radio frequency identification transceiver and antenna

TL;DR: An enclosed transceiver as discussed by the authors includes an integrated circuit and a battery together laminated between two films, and printed conductors on each film couple operative power to the integrated circuit for sending and receiving signals.
Patent

Combined digital adaptive pre-distorter and pre-equalizer system for modems in link hopping radio networks

TL;DR: In this paper, a method for a combined adaptive digital pre-distorter and pre-equalizer apparatus in single and/or multiple-link hopping radio systems including hopping among a plurality of radio links to transmit variable-length bursts of radio signals was proposed.
Patent

Process for compensating nonlinearities in an amplifier circuit

TL;DR: In this article, a predistortion filter is connected upstream of the amplifier circuit, and an aggregate signal ##EQU1## is formed in said filter from the input signal s(t).
Patent

Advanced adaptive pre-distortion in a radio frequency transmitter

TL;DR: In this paper, the main signal component of a down-converted output of an RF transmitter is removed prior to the analog-to-digital conversion of the down converted output.