Telefonaktiebolaget Lm Ericsson (publ)

Rui Hou

Lars Ridell Virtanen

Stefan Engström

Andre Bleker

Bo Göransson

Richard Hellberg

Leonard Rexberg

Mats Klingberg

Ashim Biswas

Haiying Cao

Jessica Chani

Per Landin

Mohamed Hamid

Ling Qin

Shoaib Amin

A radio transmitter as well as a method and a controller therefor are disclosed. According to an embodiment, the radio transmitter comprises a power amplifier, a filter unit, a circulator, a switch and a reflection cancellation unit. The filter unit is capable of filtering an output from the power amplifier during a downlink time division duplex (TDD) slot and filtering an uplink signal during an uplink TDD slot. The circulator has a first port coupled to the power amplifier, a second port coupled to the filter unit, and a third port coupled to the switch. The switch is capable of coupling the third port of the circulator to a termination load during the downlink TDD slot and coupling the third port of the circulator to an uplink reception path during the uplink TDD slot. The reflection cancellation unit is coupled between the switch and the termination load and is capable of generating a first reflection signal that propagates to the first port of the circulator via the switch and the third port of the circulator during the downlink TDD slot.

Radio transmitter as well as method and controller therefor

The present disclosure provides a method of linearization for a non-linear system, comprising: a group of steps comprising: inputting an input signal to the non-linear system; obtaining an output signal from the non-linear system in response to the input signal being input to the non-linear system; obtaining a desired signal for the non-linear system; comparing the output signal with the desired signal, to determine whether the input signal is a target signal for the non-linear system to achieve a desired performance; and in response to determining that the input signal is not the target signal for the non-linear system to achieve the desired performance, generating an updated signal in frequency domain by applying a coefficient to eliminate a difference between the output signal and the desired signal, for updating the input signal to the non-linear system. The present disclosure also provides a corresponding device, computer programs, and computer-readable storage.

Method and system of linearization for non-linear system

A method for crest factor reduction (CFR). The method includes: generating a signal, x(t); generating a vector, x(t), of size N&#xd7;1 based on x(t), wherein N&#x3e;1; generating a clipping signal vector, z(t), based on x(t), wherein z(t) is a vector of size N&#xd7;1; producing a transformed signal vector, y(t), based on z(t), wherein y(t) is a vector of size N&#xd7;1; and generating an output signal vector, x(t), based on y(t) and x(t), wherein generating x(t) comprises subtracting y(t) from x(t) and x(t) is a vector of size N&#xd7;1.

Crest factor reduction

In one aspect, a power amplifier apparatus comprising a power amplifier (PA) and an adaptive controller is provided. The PA comprises at least one transistor and the adaptive controller is configured to control a bias voltage of the transistor based on a measured power efficiency of the PA and a measure output signal quality of the PA. In another aspect, a method of optimizing PA performance is provided. The PA comprises at least one transistor and the method includes initializing a bias voltage of the transistor, receiving measurements indicating a power efficiency and an output signal quality of the PA, evaluating the received measurements, calculating a new bias voltage for the transistor based on the evaluation, and applying the calculated new bias voltage to the transistor.

Super-linear power amplifiers with adaptive biasing

Systems and methods for ultra-wideband Crest Factor Reduction (CFR) are provided. In some embodiments, a method performed by a wireless node for performing CFR includes performing a first CFR step on a plurality of input signals at a first sampling rate with joint peak detection and band-specific noise shaping; and performing a second CFR step on the resulting plurality of input signals at a second sampling rate with joint peak detection and joint noise shaping where the second sampling rate is higher than the first sampling rate. In this way, Peak-to-Average Power Ratio (PAPR) reduction may be increased while the computational complexity is reduced.

Ultra-wideband crest factor reduction

An amplifier arrangement for amplifying an input signal to an output signal for delivering to a load is disclosed. The amplifier arrangement comprises a power splitter configured to receive the input signal and produce split input signals. The amplifier arrangement further comprises a first amplifier branch comprising multiple main amplifier circuits. Output signals of the multiple main amplifier circuits are combined to generate a first output signal. The amplifier arrangement further comprises a second amplifier branch comprising at least one auxiliary amplifier circuit. The at least one auxiliary amplifier circuit is configured to receive a split input signal from the power splitter and produce a second output signal. The amplifier arrangement further comprises a power combiner configured to receive the first and second output signals and produce the output signal for delivering to the load.

Linear doherty power amplifier

An amplifier arrangement () for amplifying input signals and a method for operating the amplifier arrangement are disclosed. The amplifier arrangement () comprises a main amplifier circuit () having an input and an output; a first () and second () auxiliary amplifier circuits each having an input and an output, wherein each of the first () and second () auxiliary amplifier circuits being selectively operable to operate in combination with the main amplifier circuit (). The amplifier arrangement () further comprises a single hybrid coupler circuit () having a first port () being coupled to the output of the main amplifier circuit (), a second port () being coupled to the output of the first auxiliary amplifier circuit (), a third port () being coupled to the output of the second auxiliary amplifier circuit () and a fourth port () being coupled to the load () of the amplifier ().

Amplifier arrangement

There is provided a circulator device. The circulator device comprises two magnet-free circulators. Each magnet-free circulator has a forced time variance. The circulator device comprises ports. The two circulators are in the circulator device arranged to have mutually anti-phase time variance. Each of the two circulators is coupled to all of the ports. There is also presented an isolator device comprising such a circulator device. There is also presented a radio transceiver device comprising such a circulator device or isolator device.

Growing community of inventors

Järfälla, Sweden

Rui Hou