On a class of generalized MSK
Abstract
Minimum shift keying (MSK) has the property that it may be represented as an instance of generalized Offset Quadrature Phase-Shift Keying (OQPSK). This has allowed MSK to be analyzed as two independent Pulse Amplitude Modulation (PAM) schemes in quadrature. In this paper, it is shown that this representation can be used as a good approximation to a larger class of Continuous-Phase, Frequency-Shift Keyed (CPFSK) signals, possessing similar phase properties. In particular, such schemes may be described approximately as MSK with intersymbol interference. This description is used to analyze a class of schemes applying correlative coding with coding polynomials of the form (1+kD+D-squared)/(2+k) to an MSK-type FM system. Spectral properties and eye diagrams are given for these schemes. It is found that, based on spectral and error performance considerations, the best schemes result for values of about 2.0, that is, among these schemes, Tamed Frequency Modulation (TFM) is near-optimal.
- Publication:
-
ICC 1981; International Conference on Communications, Volume 1
- Pub Date:
- 1981
- Bibcode:
- 1981icc.....1....2G
- Keywords:
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- Continuous Radiation;
- Frequency Shift Keying;
- Intersymbolic Interference;
- Signal Processing;
- Transmission Efficiency;
- Large Scale Integration;
- Optimal Control;
- Phase Coherence;
- Polynomials;
- Quadratures;
- Communications and Radar