Distortion adapter receiver having intersymbol interference correction
First Claim
1. A differentially adaptive receiver comprising:
- means for receiving multipath distorted phase shift keyed pulse signals;
means for deriving a reference signal having substantially the same envelope as pulses of received signals and a phase state independent of changes of phase state in said received signals;
means for detecting the phase state of said received signal pulses, said detecting means comprising means for comparing the phase state of said received signals with the phase state of said reference signal; and
means for compensating said received signals for intersymbol interference.
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Abstract
A differentially adaptive receiver system in which correction is provided for degradation of performance caused by overlapping of adjacent data pulses. A reference signal is produced having the same complex envelope as the received signals and having a constant phase state independent of changes of phase state of the received signals. The received signals are detected against the reference signal as in an ideal matched filter receiver. The detected signals are integrated by an integrate and dump filter over the duration of the pulse period. A correction signal representing the amount of overlap between overlapping adjacent pulses is summed with the output of the integrated dump filter. The sum of the correction signal and integrate and dump filter output is sampled and held by sample and hold circuit to produce the digital data output.
116 Citations
21 Claims
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1. A differentially adaptive receiver comprising:
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means for receiving multipath distorted phase shift keyed pulse signals; means for deriving a reference signal having substantially the same envelope as pulses of received signals and a phase state independent of changes of phase state in said received signals; means for detecting the phase state of said received signal pulses, said detecting means comprising means for comparing the phase state of said received signals with the phase state of said reference signal; and means for compensating said received signals for intersymbol interference. - View Dependent Claims (2, 3, 4, 5)
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6. A receiver comprising in combination:
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means for producing a signal representing the integral of detected received signals, said received signals comprising a series of pulses, each of said pulses representing a discrete digital state; means for producing an output signal representing the discrete digital states of said received signals; means for producing an error signal representing the difference between said output signal and said signal representing said integral; means for producing a correcting signal in response to said error signal; and means for summing said signal representing the integral and said correcting signal. - View Dependent Claims (7, 8, 9, 10)
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11. In combination:
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means for receiving multipath distorted phase shift keyed pulse signals; means for deriving a reference signal having substantially the same envelope as the received signal pulses and a phase state independent of changes of phase state in said received signals; means for detecting the phase state of said received signal pulses, said detecting means comprising means for comparing the phase state of said received signals with the phase state of said reference signal; means for integrating the detected signal; means for summing the integrated detected signal with a correction signal; means for sampling the sum produced by said summing means; means for producing an output signal in response to the sampled sum; means for producing a signal representing the difference between said sum produced by said summing means and said output signal; means for storing a signal representing the phase state of the immediately previously received pulse signal; first multiplying means for multiplying said signal representing said difference by said signal stored in said storing means; means for producing a signal representing the average of the output of said first multiplying means over at least a portion of a pulse period; second multiplying means for multiplying said signal representing said average by said signal stored in said storing means, said correcting signal being produced as the product produced by said second multiplying means. - View Dependent Claims (12, 13, 14)
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15. In combination:
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means for receiving multipath distorted phase shift keyed signals upon a plurality of channels; means for deriving a reference signal for each of said channels having substantially the same complex envelope as the signals received in that channel; means for comparing the received signals in each channel with the reference signal of that channel; means for producing a detected signal in each of said channels as a result of said comparing means; means for producing the integral of the output signal from said detecting means in each of said channels; means for sampling the output of each of said integrating means in each of said channels; means for producing an output signal in each of said channels representing the amplitude of the sampled signal in each of said channels; and means for producing a correction signal in each of said channels in response to the output signal of each channel representing the amount of overlap between adjacent signals within that channel and between signals in that channel and other ones of said channel. - View Dependent Claims (16)
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17. The method comprising the steps of:
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producing a signal representing the integral of detected received signals, said received signals comprising a series of pulses, each of said pulses representing a discrete digital state; producing an output signal representing the discrete digital states of said received signals; producing an error signal representing the difference between said output signal and said signal representing said integral of detected received signals; and producing a correcting signal in response to said error signal. - View Dependent Claims (18, 19, 20, 21)
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Specification