Demodulators – Frequency shift keying or minimum shift keying demodulator – Input signal combined with local oscillator or carrier...
Patent
1994-01-31
1995-07-25
Pascal, Robert J.
Demodulators
Frequency shift keying or minimum shift keying demodulator
Input signal combined with local oscillator or carrier...
329303, 329341, H03D 500
Patent
active
054365899
ABSTRACT:
A demodulator (414) for improving bit error rate performance where alternating bit patterns produce the worst occurrences of bit errors. The demodulator (414) consists of a zero threshold comparator circuit (502), a first threshold detector circuit (508), and a second threshold detector circuit (504). The zero threshold comparator circuit (502) receives a frequency information signal and slices it into a plurality of bits (522). The first threshold detector circuit (508) compares the frequency information signal to a predetermined threshold, which is selected to optimize bit error rate performance. The second detector threshold circuit (504) is used to ensure that an alternating bit pattern has occurred. The demodulator (414) also includes a control device circuit (516) for coupling the plurality of bits (522) from the zero threshold comparator (502) to the output of the control device as a decision output signal (416) when the frequency information signal falls outside of either the first or second detector thresholds (508), (504). If the frequency information signal falls within both thresholds of the detector devices then the decision output signal (416) for the control device (516) is formed by inverting the bit decision from the previous bit interval.
REFERENCES:
patent: 3571712 (1971-03-01), Hellwarth et al.
patent: 4190802 (1980-02-01), Levine
patent: 4479092 (1984-10-01), Falconer
patent: 4561098 (1985-12-01), von Tol
patent: 4716376 (1987-12-01), Daudelin
patent: 4922206 (1990-05-01), Nicholas
patent: 4961206 (1990-10-01), Tomlinson et al.
patent: 5001724 (1991-03-01), Birgenbeier et al.
patent: 5049830 (1991-09-01), Yoshida
patent: 5058136 (1991-10-01), Kazecki et al.
patent: 5067139 (1991-11-01), Baker et al.
patent: 5084669 (1992-01-01), Dent
patent: 5121070 (1992-06-01), Tomita
patent: 5122758 (1992-06-01), Tomita
"Multilevel Decision Method for Band-limited Digital FM with Limiter--Discriminator Detection, Hirono, Masahiko Miki, Toshio and Murota, Kazuaki," IEEE Transactions on Vehicular Technology, vol. Vt-33, No. 3, Aug. 1984.
Carney Michael J.
La Rosa Christopher P.
Motorola Inc.
Nichols Daniel K.
Pascal Robert J.
Vu David H.
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