Analog baseband processor for CDMA/FM portable cellular telephones

Author

Nettles, M. ; Menping Chang ; McAllister, G. ; Nise, B. ; Persico, C. ; Sahota, K. ; Tero, J.

Author_Institution

Qualcomm Inc., San Diego, CA, USA

fYear

1995

fDate

15-17 Feb. 1995

Firstpage

328

Lastpage

329

Abstract

62The analog baseband processor is designed for use in dual-mode CDMA/FM cellular telephones, and contains both receive (RX) and transmit (TX) circuitry. The challenge presented by this circuit is to maintain low noise and precise filter characteristics in a high-gain, high-offset system and to recover a small input signal (1mVrms) in the presence of a large jammer (800mVpp). The primary function of the RX circuitry is the down-conversion of IF (intermediate frequency) to analog baseband followed by conversion to digital signals. TX circuits convert digital data into analog baseband signals that are then up-converted to IF. Both CDMA and FM analog processing are done by the circuit. A corresponding digital processor completes the CDMA and FM processing tasks.

Keywords

analogue processing circuits; cellular radio; code division multiple access; frequency modulation; land mobile radio; mobile radio; telephone sets; IF system; analog baseband processor; digital signals; down-conversion; dual-mode CDMA/FM portable cellular telephones; filter; high-gain high-offset system; jammer; noise; receive circuitry; transmit circuitry; up-conversion; Baseband; Circuit noise; Circuit optimization; Clocks; Filtering; Frequency modulation; Low pass filters; Multiaccess communication; Telephony; Voltage-controlled oscillators;

fLanguage

English

Publisher

ieee

Conference_Titel

Solid-State Circuits Conference, 1995. Digest of Technical Papers. 41st ISSCC, 1995 IEEE International

Conference_Location

San Francisco, CA, USA

ISSN

0193-6530

Print_ISBN

0-7803-2495-1

Type

conf

DOI

10.1109/ISSCC.1995.535575

Filename

535575