Performance evaluation of various decision schemes for frequency demodulation of narrow-band digital FM signals in land mobile radio

• Published in: IEEE transactions on vehicular technology Vol. 39; no. 2; pp. 109 - 116
• Main Authors: Ohno, K., Adachi, F.
• Format: Journal Article
• Language: English
• Published: New York, NY IEEE 01.05.1990; Institute of Electrical and Electronics Engineers
• Subjects: Additive white noise; Applied sciences; Bit error rate; Decision feedback equalizers; Demodulation; Equipments and installations; Error analysis; Exact sciences and technology; Fading; Frequency estimation; Interference; Laboratories; Maximum likelihood estimation; Mobile radiocommunication systems; Radiocommunications; Telecommunications; Telecommunications and information theory; Shift; Mobile radiocommunication; Frequency modulation; Intersymbol interference; Narrow band signal; Error rate; Decision circuit; Data transmission; Error correction; Performance; Demodulation; Digital signal
• ISSN: 0018-9545; 1939-9359
• DOI: 10.1109/25.54227

The decision feedback equalizer (DFE), three-level eye, and maximum-likelihood sequence estimator (MLSE) decision schemes for frequency demodulation of 16-kb/s GMSK signals are evaluated. Laboratory experimental results on bit error rate (BER) and block error rate (BKER) performances are presented. In additive white Gaussian noise channels, two-bit DFE achieves the best BER performance, whereas MLSE is the best for cochannel interference-limited channels. BKER performance was also examined. The three-level eye decision is a bit-by-bit decision, and thus has superior performance because there is no error propagation. In fading environments, however, this superiority tends to diminish because bursty errors due to deep fades predominate rather than error propagation effects. Some of the laboratory experimental results have been confirmed with field experiments at a 1.45-GHz carrier frequency.< >