A new method of an IF I/Q demodulator for narrowband signals

Author

Xue, R. ; Xu, Q. ; Chang, K.F. ; Tam, K.W.

Author_Institution

Univ. of Macau, Macau

fYear

2005

fDate

23-26 May 2005

Firstpage

3817

Abstract

I/Q demodulators have been widely used for demodulating quadrature modulated signals such as the QPSK signal and GMSK signal. Conventional analog/digital I/Q demodulators have some serious disadvantages. In this paper we present two new digital I/Q demodulators for narrowband signals, in which digital filters will not be used. The simulation results are also presented. Due to the higher sample rate and resolution the influence of the quantization noise can be ignored. The new I/Q demodulators maintain the advantages of the earlier digital I/Q demodulator such as zero DC offset and matched channel frequency responses, but their structures are much more simple.

Keywords

demodulators; digital communication; frequency response; minimum shift keying; quadrature phase shift keying; signal resolution; signal sampling; GMSK signal; IF I/Q demodulator; QPSK signal; analog/digital I/Q demodulators; demodulator structure; digital I/Q demodulators; digital filters; matched channel frequency responses; narrowband signals; quadrature modulated signals; sample rate; signal resolution; simulation; zero DC offset; Band pass filters; Baseband; Converters; Demodulation; Digital filters; Frequency conversion; Mixers; Narrowband; Quadrature phase shift keying; Signal generators;

fLanguage

English

Publisher

ieee

Conference_Titel

Circuits and Systems, 2005. ISCAS 2005. IEEE International Symposium on

Print_ISBN

0-7803-8834-8

Type

conf

DOI

10.1109/ISCAS.2005.1465462

Filename

1465462