An analog-digital adaptive image-reject technique for quadrature receivers

Author

Hajirostam, Mohammad ; Martin, Ken

Author_Institution

Dept. of Electr. & Comput. Eng., Toronto Univ., Ont., Canada

Volume

3

fYear

2005

fDate

28 Aug.-2 Sept. 2005

Abstract

In this paper, an analog-digital adaptive image-reject (IR) technique for quadrature receivers is presented. In these receivers, I/Q mismatches degrade the image rejection performance. To compensate the mismatches, a complex error signal is generated digitally of which the real and imaginary parts are proportional to the I/Q amplitude and phase mismatches. This error signal is applied to Digitally-Controlled Multiplier-Adder (DCMA) blocks to correct the phase and amplitude mismatches. Simulations show that the Image-rejection ratio is improved to more than 57 dB for a low-W cable modem receiver. This performance is independent of the synchronization and equalization of the receiver.

Keywords

adders; analogue-digital conversion; modems; multiplying circuits; optical receivers; synchronisation; I/Q amplitude; I/Q mismatches; analog-digital adaptive image-reject; complex error signal; digitally-controlled multiplier-adder block; equalization; image degradation; image rejection; low-W cable modem receiver; mismatch compensation; phase mismatch; quadrature receiver; synchronization; Analog-digital conversion; Degradation; Equations; Error correction; Filtering; Frequency; Image converters; Image retrieval; Interference; Signal generators;

fLanguage

English

Publisher

ieee

Conference_Titel

Circuit Theory and Design, 2005. Proceedings of the 2005 European Conference on

Print_ISBN

0-7803-9066-0

Type

conf

DOI

10.1109/ECCTD.2005.1523115

Filename

1523115