Title :
Compensation of IQ imbalance and transmitter nonlinearities in broadband MIMO-OFDM
Author :
Gregorio, F. ; Cousseau, J. ; Werner, S. ; Riihonen, T. ; Wichman, R.
Author_Institution :
Dept. of Electr. & Comput. Eng., Univ. Nac. del Sur, Bahia Blanca, Argentina
Abstract :
Predistortion techniques are implemented in OFDM systems to improve power amplifier efficiency while keeping in-band and out- of-band distortion at acceptable levels. Predistorter (PD) design for broadband MIMO-OFDM systems introduces several implementation challenges. Coupling effects cannot be avoided in MIMO transceivers where the paths are implemented on the same chipset. Moreover, baseband PDs are affected by imbalances in the IQ modulator. This paper proposes a MIMO-PD that linearizes the power amplifier (PA) response and compensates for both crosstalk and IQ imbalance. Error vector magnitude (EVM) and adjacent channel power ratio (ACPR) results show a significant improvement compared with conventional PD systems.
Keywords :
MIMO communication; OFDM modulation; broadband networks; crosstalk; power amplifiers; radio transmitters; wireless channels; IQ imbalance; IQ modulator; MIMO transceiver; MIMO-PD system; OFDM system; adjacent channel power ratio; broadband MIMO-OFDM system; coupling effect; error vector magnitude; in-band distortion; out-of-band distortion; power amplifier efficiency; power amplifier response; predistorter design; predistortion technique; transmitter nonlinearity; Couplings; Crosstalk; MIMO; Noise; OFDM; Polynomials; Transmitters;
Conference_Titel :
Circuits and Systems (ISCAS), 2011 IEEE International Symposium on
Conference_Location :
Rio de Janeiro
Print_ISBN :
978-1-4244-9473-6
Electronic_ISBN :
0271-4302
DOI :
10.1109/ISCAS.2011.5938085
