DocumentCode :
3180795
Title :
Pilot-Based Compensation of Frequency-Selective I/Q Imbalances in Direct-Conversion OFDM Transmitters
Author :
Zou, Yaning ; Valkama, Mikko ; Renfors, Markku
Author_Institution :
Dept. of Commun. Eng., Tampere Univ. of Technol., Tampere
fYear :
2008
fDate :
21-24 Sept. 2008
Firstpage :
1
Lastpage :
5
Abstract :
This paper presents a pilot-based compensation algorithm for mitigation of frequency-selective I/Q imbalances in direct-conversion OFDM transmitters. By deploying a feedback loop from RF to baseband, together with a properly-designed pilot signal structure, the I/Q imbalance properties of the transmitter are efficiently estimated in a subcarrier-wise manner. Based on the obtained I/Q imbalance knowledge, the imbalance effects on the actual transmit waveform are then mitigated by baseband pre-distortion acting on the mirror-subcarrier signals. The compensation performance of the proposed structure is analyzed using extensive computer simulations, indicating that very high image rejection ratios can be achieved in practical system set-ups with reasonable pilot signal lengths.
Keywords :
OFDM modulation; radio transmitters; baseband predistortion; direct-conversion OFDM transmitters; extensive computer simulations; feedback loop; frequency-selective I-Q imbalances; mirror-subcarrier signal; pilot-based compensation; subcarrier-wise manner; waveform; Baseband; Computer simulation; Feedback loop; Image analysis; OFDM; Performance analysis; RF signals; Radio frequency; Signal analysis; Transmitters;
fLanguage :
English
Publisher :
ieee
Conference_Titel :
Vehicular Technology Conference, 2008. VTC 2008-Fall. IEEE 68th
Conference_Location :
Calgary, BC
ISSN :
1090-3038
Print_ISBN :
978-1-4244-1721-6
Electronic_ISBN :
1090-3038
Type :
conf
DOI :
10.1109/VETECF.2008.228
Filename :
4657060
Link To Document :
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