Wireless FSK technique for telemetering underground data to the surface
First Claim
1. A FSK telemetery system for transmitting data pulses of different frequencies through the earth and for receiving and converting these transmitted pulses to binary data comprising:
- means for forming continuous narrow bandwidth pulses having either of two distinct low frequencies with each having its own total duty cycle;
means for shortening the time duration of both of said formed continuous pulses to form pulses of tone bursts with the same distinct frequencies over no more than about ten percent of their respective total duty cycles;
means for transmitting either of the two formed tone bursts through the earth;
portable self contained power supply means for providing power to said forming, shortening and transmitting means;
means for receiving said transmitted tone bursts after then have transversed through the earth, said receiving means having an exclusive OR circuit to reject received pulses when both of the distinct low frequency pulses are simultaneously present; and
digital storage data means for storing said received pulses as binary representations thereof.
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Accused Products
Abstract
A Frequency Shift Keying (FSK) system to transmit and receive data as a sequence of dual frequency short duration tone bursts. Normally the data is transmitted from an underground location, as in a mine, to the surface or to another underground location. At the receiving end the transmitted data is detected as marks or spaces that are used to clock the appropriate data bits into a storage shift register. Erroneous data from wideband noise transients at the receiver are eliminated by the use of an exclusive OR circuit which permits shift pulses to appear at the data register only when one or the other of the two shift pulses are present but not both. To further insure accurate copy of the digital data at the receiver, a receiver alert code is transmitted prior to the telemetering of the actual data. Only after recognition of the receiver alert code is the receiver able to receive the transmitted data bit stream.
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Citations
6 Claims
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1. A FSK telemetery system for transmitting data pulses of different frequencies through the earth and for receiving and converting these transmitted pulses to binary data comprising:
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means for forming continuous narrow bandwidth pulses having either of two distinct low frequencies with each having its own total duty cycle; means for shortening the time duration of both of said formed continuous pulses to form pulses of tone bursts with the same distinct frequencies over no more than about ten percent of their respective total duty cycles; means for transmitting either of the two formed tone bursts through the earth; portable self contained power supply means for providing power to said forming, shortening and transmitting means; means for receiving said transmitted tone bursts after then have transversed through the earth, said receiving means having an exclusive OR circuit to reject received pulses when both of the distinct low frequency pulses are simultaneously present; and digital storage data means for storing said received pulses as binary representations thereof. - View Dependent Claims (2, 3, 4, 5, 6)
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Specification