Apparatus and method for wideband communication with suppression of harmonic interference
First Claim
1. A method for transmitting information with a desired bandwidth while suppressing interference thereto from harmonics of a system-wide signal, comprising the steps of:
- (a) providing a data carrier having a frequency essentially midway between an adjacent pair of harmonics of the system-wide signal;
(b) transforming each of a plurality of bits of the information into a signal comprising a pair of like-polarity pulses, each pulse having a time duration T;
(c) setting a time interval P between the pair of pulses to be essentially equal to twice the reciprocal of the frequency difference between the frequency of the data carrier and the frequency of the adjacent harmonics of the system-wide signal;
(d) modulating one of the parameters of the data carrier with the pulse-pair signal to be transmitted;
(e) transmitting the modulated data carrier to a receiving end; and
(f) detecting the pulse-pair signal to recover at the receiving end each bit of data therein.
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Accused Products
Abstract
A method for transmitting information with a desired bandwidth while suppressing interference due to harmonics of a system-wide signal, by transmitting each bit of information as a pair of spaced rectangular envelope modulation pulses having a time interval therebetween essentially equal to the reciprocal of the difference between the frequencies of a carrier and of adjacent harmonics of the undesired system-wide signal. A sequential plurality of double-pulse modulating waveforms can be transmitted for reception by a receiving means having a like plurality of demodulators each synchronized and sequentially enabled only when one of the pair of modulating pulses are present. A novel double-pulse demodulator means, capable of essentially rejecting undesirable harmonics in a system utilizing a data carrier modulated to be interlaced between sequential harmonics of a system-wide signal, and novel means for synchronous gating thereof, are disclosed.
20 Citations
21 Claims
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1. A method for transmitting information with a desired bandwidth while suppressing interference thereto from harmonics of a system-wide signal, comprising the steps of:
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(a) providing a data carrier having a frequency essentially midway between an adjacent pair of harmonics of the system-wide signal; (b) transforming each of a plurality of bits of the information into a signal comprising a pair of like-polarity pulses, each pulse having a time duration T; (c) setting a time interval P between the pair of pulses to be essentially equal to twice the reciprocal of the frequency difference between the frequency of the data carrier and the frequency of the adjacent harmonics of the system-wide signal; (d) modulating one of the parameters of the data carrier with the pulse-pair signal to be transmitted; (e) transmitting the modulated data carrier to a receiving end; and (f) detecting the pulse-pair signal to recover at the receiving end each bit of data therein. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10, 12, 13, 14)
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11. Apparatus for receiving information transmitted as a plurality of bits of information, each bit modulating a data carrier having a carrier frequency essentially interlaced midway between a pair of adjacent harmonics of a system-wide signal, with a pair of like-polarity signal pulses having a pulse duration T and a time interval P between pulses, comprising:
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means for receiving the modulated data carrier; demodulator means for recovering the pulse-pair modulation signal from the modulated data carrier; detector means receiving the pulse-pair modulated signal for recovering the value of the bit of information responsive to both pulses of a modulation signal, said detector means comprising input means for receiving the pulse-pair modulation signal; first means for integrating the amplitude of said signal; first switch means for coupling said signal to said first means responsive to said first switching signal present essentially only when one of said pair of pulses should be present at said input means; second means for storing the amplitude of the integrated signal responsive to a second switching signal present only after every other occurrence of said first switching signal; and output means at which the amplitude stored in said second means appears as the recovered value of the associated bit of information; and means for synchronizing said detector means to operate only when each of said pair of pulses of a modulation signal is present.
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15. Apparatus for receiving information transmitted as a plurality of bits of information, each bit modulating a data carrier having a carrier frequency essentially interlaced midway between a pair of adjacent harmonics of a system-wide signal, with a pair of like-polarity pulse signals having a pulse duration T and time interval P between pulses, comprising:
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means for receiving the modulated data carrier; demodulator means for recovering the pulse-pair modulation signal from the modulated data carrier; detector means receiving the pulse-pair modulated signal for recovering the value of the bit of information responsive to both pulses of a modulation signal; and means for synchronizing said detector means comprising clock means having an output at a clock frequency essentially equal to the reciprocal of the time interval P between pulses; means for generating a pulse of duration T at the essentially identical point during each cycle of the output of said clock means to generate said first switching signal; and third means coupled to said demodulator means for synchronizing said clock means to cause said first switching signal to be present essentially in synchronism with each one of said pair of pulses. - View Dependent Claims (16, 17, 18, 19, 20, 21)
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Specification