A Class of Two-Symbol-Interval Modems for Nonlinear Radio Systems

Author

Van, Hiep Pham ; Feher, Kamilo

Author_Institution

Spar Aerospace Limited, Ste. Anne de Bellevue, P.Q., Canada and Univ. of Ottawa, Ottawa, Ont., Canada

Volume

31

Issue

3

fYear

1983

fDate

3/1/1983 12:00:00 AM

Firstpage

433

Lastpage

441

Abstract

Based on Feher\´s nonlinear filter (NLF) invention, we developed a class of intersymbol-interference and jitter-free (IJF) baseband signals and JJF-OQPSK systems. In [14] and [18] we demonstrated the performance advantages of these systems over QPSK, OQPSK, and MSK systems. In this paper a new class of IJF two-symbol-interval (TSI) baseband pulse shapes is introduced. The spectral properties and the Peperformance of these TSI-OQPSK modulated systems is investigated. We show that in a hard-limited radio system the main lobe of the $n \\geq 2$ , TSI-OQPSK is narrower and that the sidelobes, in the critical $|(f-f_{c})T_{s}| < 2$ region, are lower than that of QPSK, OQPSK, MSK, and $N = 1$ , IJF-OQPSK systems. A new filtering strategy, the sum of approximate eye (SAE), is also introduced. It is shown that SAE filters may reduce the $E_{b}/N_{0}$ requirements of band-limited and hard-limited TSI-OQPSK modems.

Keywords

Filtering; Intersymbol interference; Jitter; Nonlinear distortions; Phase-shift keying; Radio communication; Baseband; Filters; Modems; Power system restoration; Pulse amplifiers; Pulse modulation; Pulse shaping methods; Quadrature phase shift keying; Shape; Signal restoration;

fLanguage

English

Journal_Title

Communications, IEEE Transactions on

Publisher

ieee

ISSN

0090-6778

Type

jour

DOI

10.1109/TCOM.1983.1095822

Filename

1095822