Nyquist QPSK transmission using rational-function filter for mobile radio

Tadao Takami, Shigeki Saito, Shigeru Tomisato, Yasushi Yamao

Research output: Chapter in Book/Report/Conference proceedingConference contribution

1 Citation (Scopus)


The design and implementation of a Nyquist QPSK (quadrature phase-shift keying) transmission scheme using a rational-function receiving filter are presented. The scheme is suitable for mobile radios which must be as small as possible and operate with limited power sources. A transitional Butterworth-Thomson (TBT) filter is examined as a rational-function filter, and a ceramic receiving filter is developed with optimum TBT characteristics. π/4-shifted QPSK transmission experiments using this filter are conducted. The experimental results show that the required input level and cochannel interference are superior by 1 dB to 0.9 dB, respectively, to those of the conventional transmission scheme. The maximum permissive delay spread in frequency-selective fading channels is improved by around 30%.

Original languageEnglish
Title of host publicationIEEE Vehicular Technology Conference
PublisherPubl by IEEE
Number of pages6
ISBN (Print)0879425822
Publication statusPublished - May 1991
Externally publishedYes
Event41st IEEE Vehicular Technology Conference - St. Louis, MO, USA
Duration: May 19 1991May 22 1991


Other41st IEEE Vehicular Technology Conference
CitySt. Louis, MO, USA


ASJC Scopus subject areas

  • Electrical and Electronic Engineering

Cite this

Takami, T., Saito, S., Tomisato, S., & Yamao, Y. (1991). Nyquist QPSK transmission using rational-function filter for mobile radio. In IEEE Vehicular Technology Conference (pp. 663-668). Publ by IEEE.