US 4,291,275 A · Frequency demodulation system

Abstract

A demodulator for demodulating an encoded signal comprising first and second predetermined patterns of contiguous signal segments of frequencies f.sub.1 and f.sub.2. A first signal processing means comprises first correlation means including a reference signal which is correlative with the signal segments of frequency f.sub.1 of said first and second patterns to produce a first and second output signals when correlation occurs. A second signal processing means comprising second correlation means including a reference signal which is correlative with the signal segments of frequency f.sub.2 of said first and second patterns to produce third and fourth output signals when correlation occurs. The said first and third output signals are combined to produce a first resultant signal indicating correlation with said first pattern of signal segments and said second and fourth output signals are combined to produce a second resultant signal indicating correlation with said second pattern of signal segments.

Claims7

Dependent claims

Means for demodulating a received encoded signal encoded with at least one predetermined pattern of successive signal segments of frequencies f.sub.1 and f.sub.2, and comprising:

first signal processing means responsive to said encoded signal and comprising first correlation means;
said first correlation means comprising first register means containing a first staticized reference signal having a first pattern of binary 1's and 0's correlative with the signal segments of frequency f.sub.1 to produce a first output signal when correlation occurs;
second signal processing means responsive to said encoded signal and comprising second correlation means;
said second correlation means comprising second register means containing a second staticized reference signal having a second pattern of binary 1's and 0's complementary to said first staticized pattern and correlative with the signal segments of frequency f.sub.2 to produce a second output signal when correlation occurs;
and
means for combining said first and second output signals to produce a resultant output signal indicating correlation with said at least one pattern of signal segments.

3 more elements

Means for demodulating an encoded signal comprising first and second predetermined patterns of successive signal segments of frequencies f.sub.1 and f.sub.2, and comprising:

first signal processing means responsive to said encoded signal and comprising first correlation means;
said first correlation means comprising first and second register means containing first and second staticized reference signals respectively having said first and second patterns of binary 1's and 0's correlative with the signal segments of frequency f.sub.1 to produce first and second output signals when correlation occurs;
second signal processing means responsive to said encoded signal and comprising second correlation means;
said second correlation means comprising third and fourth register means containing third and fourth staticized reference signals respectively having said second and first patterns of binary 1's and 0's correlative with the signal segments of frequency f.sub.2 to produce third and fourth output signals when correlation occurs;
and means for combining said first and third output signals to produce a first resultant output signal indicating correlation with said first pattern of signal segments and for combining said second and fourth output signals to produce a second resultant signal indicating correlation with said second pattern of signal segments.

2 more elements

Dependencies are inferred from the claim text.

Frequency demodulation system

Life of this patent

Frequency demodulation system

Life of this patent

Abstract

Claims7