A direct pi /4 DQPSK modulator with memory based prefiltering and predistortion

Author

Kumar, Surinder ; Danshin, Tom

Author_Institution

Telecommun. Res. Lab., Saskatoon, Sask., Canada

fYear

1993

fDate

6/15/1905 12:00:00 AM

Firstpage

208

Lastpage

211

Abstract

A direct pi /4 differential quadrature phase shift keying (DQPSK) 48.6-kb/s 824-849-MHz modulator for North American digital cellular applications is described. Square root raised cosine roll-off prefiltering with a roll-off factor 0.35 is implemented using digital memory circuits. The same memory circuits are used to incorporate predistortion for the nonlinearity of the biphase attenuators. Although predistortion for the modulator only has been incorporated, the same circuit can be used to predistort for power amplifier nonlinearities. The modulator is suitable for silicon monolithic microwave integrated circuit (MMIC) implementation using digital and memory circuits on the same chip. The measured results are presented.

Keywords

EPROM; MMIC; digital communication systems; modulators; phase shift keying; semiconductor storage; 48.6 kbit/s; 824 to 849 MHz; DQPSK modulator; EPROM; MMIC implementation; North American digital cellular applications; PSK; Si; biphase attenuators; cosine roll-off prefiltering; differential quadrature phase shift keying; digital memory circuits; memory based prefiltering; monolithic microwave integrated circuit; predistortion; Attenuators; Differential quadrature phase shift keying; Digital modulation; MMICs; Microwave integrated circuits; Monolithic integrated circuits; Phase modulation; Power amplifiers; Predistortion; Silicon;

fLanguage

English

Publisher

ieee

Conference_Titel

WESCANEX 93. 'Communications, Computers and Power in the Modern Environment.' Conference Proceedings., IEEE

Conference_Location

Saskatoon, Sask., Canada

Print_ISBN

0-7803-1319-4

Type

conf

DOI

10.1109/WESCAN.1993.270576

Filename

270576