On the Derivation of the Ungerboeck Observation Model for Offset QPSK

Authors

Michael Rice, Brigham Young University - ProvoFollow

Keywords

Offset QPSK, Maximum likelihood sequence detection, equalization, frequency selective channels

Abstract

This report derives maximum likelihood sequence estimator for Offset QPSK (OQPSK) operating over frequency selective channel. The maximum likelihood sequence estimator takes the form of the Viterbi Algorithm operating on a trellis defined intersymbol interference caused by the frequency selective channel. Because the distorted pulse shape does not satisfy the Nyquist no-ISI criterion, the matched filter output samples contain correleted noise. The derivation uses Ungerboeck’s method to create a recursive causal metric suitable for use with the Viterbi Algorithm.

BYU ScholarsArchive Citation

Rice, Michael, "On the Derivation of the Ungerboeck Observation Model for Offset QPSK" (2025). Faculty Publications. 7807.
https://scholarsarchive.byu.edu/facpub/7807

Document Type

Report

Publication Date

2025-11-07

Language

English

College

Ira A. Fulton College of Engineering

Department

Electrical and Computer Engineering

University Standing at Time of Publication

Full Professor

Copyright Use Information

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