公开(公告)号：US20240022217A1

公开(公告)日：2024-01-18

申请号：US18351623

申请日：2023-07-13

Applicant: Nokia Solutions and Networks Oy

Inventor： Chad YOUNG ,  Tian HE ,  Shavantha KULARATNA ,  Peter NOVAK ,  Jacob Edward LONGWELL

IPC: H03F1/32

CPC classification number: H03F1/3247 ,  H03F2200/451

Abstract: As solution for predistorting a signal is presented. The solution comprises receiving (600) as an input a signal comprising at least two signal components on a different band, sampling (602) the input signal comprising linear terms, composite non-linear terms causing intermodulation outside Nyquist band of the input signal and further non-linear terms causing intermodulation inside the Nyquist band, the further non-linear terms comprising multi-band terms. Oversampling (604) by a given factor is applied to the signal in a first predistortion circuit for processing the linear terms and composite non-linear terms causing intermodulation outside Nyquist band; processing (606) the input signal without oversampling in a second predistortion circuit in parallel with the first predistortion circuit for the further non-linear terms. The rates of the output signals of the predistortion circuits are matched (608), combined and filtered (610).

公开(公告)号：US20220173704A1

公开(公告)日：2022-06-02

申请号：US17455278

申请日：2021-11-17

Applicant: Nokia Solutions and Networks Oy

Inventor： Tian HE ,  Chad YOUNG ,  Shavantha KULARATNA ,  Peter NOVAK ,  Jacob Edward LONGWELL

IPC: H03F1/32 ,  H03F3/21

Abstract: This specification relates to digital pre-distortion of signals before power amplification during the transmission of a signal. A method comprising: receiving an input signal 1st and 2nd subband signals associated with 1st and 2nd centre frequencies; applying a pre-distortion to the input signal to generate a pre-distorted signal, the pre-distortion applying an inverse to a power amplification model associated with a power amplifier; and outputting the pre-distorted signal for power amplification. The power amplification model or the inverse to the power amplification model comprises a first plurality of terms and a second plurality of terms. Each of the 1st and 2nd plurality of terms comprising a product of a complex coefficient, a power factor, and other factors depending on if it is 1st or 2nd plurality of terms.

公开(公告)号：US20250007545A1

公开(公告)日：2025-01-02

申请号：US18709577

申请日：2021-11-30

Applicant: NOKIA SOLUTIONS AND NETWORKS OY

Inventor： Long CHEN ,  Shavantha KULARATNA ,  Aki Heikki Jalmari KORHONEN

IPC: H04B1/04

Abstract: Disclosed are methods and apparatus for optimizing digital pre-distortion associated with a network device. The digital signal processing apparatus in a communication network may comprise at least one processor and at least one memory having computer program code stored thereon and configured, with the at least one processor, cause the digital signal processing apparatus as a network device to perform: splitting an input signal into two or more split signals with different frequencies, the frequency of each of said split signals being different from other said split signals; separating each of the two or more split signals into two or more component signals with different phases; and performing pre-distortion computation by using the component signals to get a pre-distorted signal to be transmitted to a power amplifier.

公开(公告)号：US20160254788A1

公开(公告)日：2016-09-01

申请号：US15026324

申请日：2014-10-01

Applicant: NOKIA SOLUTIONS AND NETWORKS OY

Inventor： Shavantha KULARATNA ,  Christian REICHL ,  Bjoern JELONNEK ,  Alan PEREIRA ,  Glenn SCHEDEEN ,  Sandeep MEHTA

IPC: H03F1/32 ,  H03F3/213 ,  H04B1/04 ,  H03F3/195

CPC classification number: H03F1/3247 ,  H03F1/02 ,  H03F3/19 ,  H03F3/195 ,  H03F3/21 ,  H03F3/213 ,  H03F3/24 ,  H03F2200/336 ,  H03F2200/451 ,  H03F2201/3227 ,  H04B1/0475 ,  H04B1/40 ,  H04B2001/0416 ,  H04B2001/045

Abstract: Enhancing the intermodulation performance of an RF power amplifier by determining a coarse time delay represented by an integer TI; determining a reference point for a transmitted signal waveform of the RF power amplifier; shifting the waveform by a set of offsets including a plurality of non-integer fractional steps; correlating the transmitted signal waveform with a feedback signal waveform to obtain a respective correlation value for each of corresponding fractional steps; obtaining an accurate fractional delay value by selecting a fractional step having a highest respective correlation value; applying the obtained correct fractional delay value to the transmitted signal waveform to provide a compensated transmitted signal waveform and combining the compensated transmitted signal waveform with the feedback signal waveform to reduce at least one intermodulation product of the RF power amplifier.

Abstract translation: 通过确定由整数TI表示的粗略时间延迟来增强RF功率放大器的互调性能; 确定RF功率放大器的发射信号波形的参考点; 将波形移位一组包括多个非整数分数步长的偏移量; 将发送的信号波形与反馈信号波形相关，以获得每个相应分数步骤的相应相关值; 通过选择具有最高各自的相关值的分数步骤来获得精确的分数延迟值; 将所获得的正确分数延迟值应用于所发送的信号波形以提供经补偿的发射信号波形，并将补偿的发射信号波形与反馈信号波形组合以减少RF功率放大器的至少一个互调乘积。

公开(公告)号：US20220376736A1

公开(公告)日：2022-11-24

申请号：US17627055

申请日：2019-07-16

Applicant: NOKIA SOLUTIONS AND NETWORKS OY

Inventor： Ramasamy GOPALAN ,  Shavantha KULARATNA ,  Artur DROZDZ

IPC: H04B1/525 ,  H04B1/12 ,  H04B1/10

Abstract: An apparatus is disclosed, comprising means for determining a noise floor for a radio frequency (RF) system. The apparatus may also comprise means for determining a Passive InterModulation (PIM) value of a component of the RF system contributing as a source of PIM; determining that a passive intermodulation (PIM) cancellation system should be enabled if the PIM value is above a predetermined threshold from the noise floor. The apparatus may also comprise means for determining that the PIM cancellation system should be disabled if the PIM value is at or below the predetermined threshold.

公开(公告)号：US20220140858A1

公开(公告)日：2022-05-05

申请号：US17511191

申请日：2021-10-26

Applicant: Nokia Solutions and Networks Oy

Inventor： Tian HE ,  Chad YOUNG ,  Shavantha KULARATNA

IPC: H04B1/62 ,  H04B1/00 ,  H04B1/04

Abstract: An apparatus is disclosed, comprising means for providing two or more amplifiers for amplifying signals in two or more respective frequency bands, receiving a composite signal comprising first and second predistorted input signals in first and second frequency bands and filtering the composite signal to provide (i) the first predistorted signal for input to a first amplifier of the two or more amplifiers for producing an amplified first output signal and (ii) the second predistorted signal for input to a second amplifier of the two or more amplifiers for producing an amplified second output signal. The apparatus may also comprise means for routing, at non-overlapping times, the first and second output signals to a common feedback path and for linearizing received first and second input signals based on the respective first and second output signals received on the common feedback path.