Transmitter IQ Imbalance Mitigation and PA Linearization in Software Defined Radios

Radio frequency (RF) power amplifiers (PA) are efficiently linearized by adaptive digital predistortion (DPD). However, performance of DPD is severely degraded in presence of transmitter’s frequency-selective in-phase/quadrature (I/Q) imbalance. We propose DPD/IQ method that compensates the effects...

Full description

Bibliographic Details
Main Authors: B. Jovanovic, S. Milenkovic
Format: Article
Language:English
Published: Spolecnost pro radioelektronicke inzenyrstvi 2022-04-01
Series:Radioengineering
Subjects:
Online Access:https://www.radioeng.cz/fulltexts/2022/22_01_0144_0154.pdf
_version_ 1811329706295820288
author B. Jovanovic
S. Milenkovic
author_facet B. Jovanovic
S. Milenkovic
author_sort B. Jovanovic
collection DOAJ
description Radio frequency (RF) power amplifiers (PA) are efficiently linearized by adaptive digital predistortion (DPD). However, performance of DPD is severely degraded in presence of transmitter’s frequency-selective in-phase/quadrature (I/Q) imbalance. We propose DPD/IQ method that compensates the effects of transmitter I/Q imbalance and PA nonlinearity, which is dedicated for implementation in low-cost software radio defined (SDR) cellular base stations. The advantage of DPD/IQ is low complexity in terms of reduced number of DPD coefficients which provides significant savings of FPGA resources. The DPD/IQ has been evaluated after method has been implemented in SDR board. Measured results clearly demonstrate efficient compensation of PA and transceiver impairments enabling transmission of wide bandwidth waveforms and realization of sophisticated modulation schemes. Improvement in image rejection ratio of 10-15dB is achieved. Considering compensation of PA nonlinearities, the ACPR at PA output is decreased by 15dBc.
first_indexed 2024-04-13T15:49:59Z
format Article
id doaj.art-7b845fc14a734924b84eafbdcdcdb87a
institution Directory Open Access Journal
issn 1210-2512
language English
last_indexed 2024-04-13T15:49:59Z
publishDate 2022-04-01
publisher Spolecnost pro radioelektronicke inzenyrstvi
record_format Article
series Radioengineering
spelling doaj.art-7b845fc14a734924b84eafbdcdcdb87a2022-12-22T02:40:53ZengSpolecnost pro radioelektronicke inzenyrstviRadioengineering1210-25122022-04-01311144154Transmitter IQ Imbalance Mitigation and PA Linearization in Software Defined RadiosB. JovanovicS. MilenkovicRadio frequency (RF) power amplifiers (PA) are efficiently linearized by adaptive digital predistortion (DPD). However, performance of DPD is severely degraded in presence of transmitter’s frequency-selective in-phase/quadrature (I/Q) imbalance. We propose DPD/IQ method that compensates the effects of transmitter I/Q imbalance and PA nonlinearity, which is dedicated for implementation in low-cost software radio defined (SDR) cellular base stations. The advantage of DPD/IQ is low complexity in terms of reduced number of DPD coefficients which provides significant savings of FPGA resources. The DPD/IQ has been evaluated after method has been implemented in SDR board. Measured results clearly demonstrate efficient compensation of PA and transceiver impairments enabling transmission of wide bandwidth waveforms and realization of sophisticated modulation schemes. Improvement in image rejection ratio of 10-15dB is achieved. Considering compensation of PA nonlinearities, the ACPR at PA output is decreased by 15dBc.https://www.radioeng.cz/fulltexts/2022/22_01_0144_0154.pdffrequency dependent i/q imbalancedigital predistortionmemory polynomialpower amplifierpa linearization
spellingShingle B. Jovanovic
S. Milenkovic
Transmitter IQ Imbalance Mitigation and PA Linearization in Software Defined Radios
Radioengineering
frequency dependent i/q imbalance
digital predistortion
memory polynomial
power amplifier
pa linearization
title Transmitter IQ Imbalance Mitigation and PA Linearization in Software Defined Radios
title_full Transmitter IQ Imbalance Mitigation and PA Linearization in Software Defined Radios
title_fullStr Transmitter IQ Imbalance Mitigation and PA Linearization in Software Defined Radios
title_full_unstemmed Transmitter IQ Imbalance Mitigation and PA Linearization in Software Defined Radios
title_short Transmitter IQ Imbalance Mitigation and PA Linearization in Software Defined Radios
title_sort transmitter iq imbalance mitigation and pa linearization in software defined radios
topic frequency dependent i/q imbalance
digital predistortion
memory polynomial
power amplifier
pa linearization
url https://www.radioeng.cz/fulltexts/2022/22_01_0144_0154.pdf
work_keys_str_mv AT bjovanovic transmitteriqimbalancemitigationandpalinearizationinsoftwaredefinedradios
AT smilenkovic transmitteriqimbalancemitigationandpalinearizationinsoftwaredefinedradios