US4653053A — Performance monitoring of antijam satellite commu…

Claim 1

Independent Claim 157 words

For use in a communications system wherein a plurality of stations communicate with one another via a transponder remote with respect to said stations, a method of measuring the performance of a communication link between a prescribed transmitting station, said transponder and a prescribed receiving station comprising the steps of: (a) at a first selected one of said stations, receiving signals transmitted from a second selected one of said stations via said transponder; (b) from the signal received in step (a), deriving a first output signal representative of a prescribed characteristic of said transponder at a symbol rate associated with signals transmitted by said prescribed transmitting station, and a second output signal representative of a prescribed characteristic of said received signals; and (c) processing said first and second output signals derived in step (b) in accordance with preselected parameters associated with said communication link so as to obtain a measurement of the performance of said communication link.

Claim 2

Dependent Claim 157 words

For use in a communications system wherein a plurality of stations communicate with one another via a transponder remote with respect to said stations, a method of measuring the performance of a communication link between a prescribed transmitting station, said transponder and a prescribed receiving station comprising the steps of: (a) at a first selected one of said stations, receiving signals transmitted from a second selected one of said stations via said transponder; (b) from the signal received in step (a), deriving a first output signal representative of a prescribed characteristic of said transponder at a symbol rate associated with signals transmitted by said prescribed transmitting station, and a second output signal representative of a prescribed characteristic of said received signals; and (c) processing said first and second output signals derived in step (b) in accordance with preselected parameters associated with said communication link so as to obtain a measurement of the performance of said communication link.

Claim 3

Dependent Claim 36 words

A method according to claim 1, wherein said prescribed characteristic of said transponder corresponds to the effective gain of said transponder and said prescribed characteristic of said received signals corresponds to the effective transponder noise density.

Claim 4

Dependent Claim 13 words

A method according to claim 2, wherein said transponder comprises a satellite transponder.

Claim 5

Dependent Claim 22 words

A method according to claim 2, wherein said first and second selected ones of said stations correspond to the same selected station.

Claim 6

Dependent Claim 36 words

A method according to claim 4, wherein said symbol rate of signals transmitted from and received by said same selected station is different from the symbol rate associated with signals transmitted by said prescribed transmitting station.

Claim 7

Dependent Claim 38 words

A method according to claim 2, wherein said preselected parameters include preestablished uplink parameters of a communication link between said prescribed transmitting station and said transponder, and preestablished downlink parameters between said transponder and said prescribed receiving station.

Claim 8

Dependent Claim 78 words

A method according to claim 2, wherein a receiving station contains a decoder for recovering data symbols in accordance with data decision signal levels and wherein step (c) includes the step of deriving first data μ ij representative of the mean value of decision signal levels on symbols transmitted from said prescribed transmitting station i and received at said prescribed receiving station j and second data representative of the variance σ 2 j of said decision signal levels.

Claim 9

Dependent Claim 71 words

A method according to claim 7, wherein said prescribed receiving station j includes an error correction decoder for correcting errors in data symbols contained in signals received at said receiving station j transmitted over said communication link from said prescribed transmitting station i, and step (c) includes the step of calculating the probability of error at the output of said error correction decoder in accordance with said first and second data.

Claim 10

Dependent Claim 35 words

A method according to claim 8, wherein step (c) includes the step of compensating said first and second data in accordance with variations in the gain of the receiver at said prescribed receiving station j.

Claim 11

Dependent Claim 41 words

A method according to claim 8, wherein step (b) comprises deriving a first signal representative of the signal power in the received signal equivalent to continuous wave signal power and a second signal representative of noise density received from said transponder.

Claim 12

Dependent Claim 101 words

A method according to claim 10, wherein step (b) includes the steps of (b1) processing said first signal in accordance with preselected uplink parameters associated with the link between said second selected one of said stations and said transponder and in accordance with preselected down link parameters associated with the link between said transponder and said first selected one of said stations to obtain said first output signal, and (b2) processing said second signal in accordance with preselected downlink parameters associated with the link between said transponder and said first selected one of said stations to obtain said second output signal.

Claim 13

Dependent Claim 22 words

A method according to claim 1, wherein signals received at said first selected one of said stations are spread spectrum encoded signals.

Claim 14

Dependent Claim 164 words

For use in a communications system wherein a plurality of stations communicate with one another via a transponder remote with respect to said stations, a method of measuring the quality of a communication link between a prescribed transmitting station i, said transponder and a prescribed receiving station j, said prescribed receiving stations j containing a decoder for recovering data symbols, transmitted by said prescribed transmitting station i, in accordance with data symbol decision signal levels, a said method comprising the steps of: (a) deriving first data μ ij representative of the mean value of decision signal levels on symbols transmitted from said prescribed transmitting station i and received at said prescribed receiving station j, and second data representative of the variance σ j 2 of said decision signal levels; and (b) calculating the probability of error in recovered data symbols at the output of said decoder in accordance with said first and second data so as to obtain said quality of said communication link.

Claim 15

Dependent Claim 164 words

For use in a communications system wherein a plurality of stations communicate with one another via a transponder remote with respect to said stations, a method of measuring the quality of a communication link between a prescribed transmitting station i, said transponder and a prescribed receiving station j, said prescribed receiving stations j containing a decoder for recovering data symbols, transmitted by said prescribed transmitting station i, in accordance with data symbol decision signal levels, a said method comprising the steps of: (a) deriving first data μ ij representative of the mean value of decision signal levels on symbols transmitted from said prescribed transmitting station i and received at said prescribed receiving station j, and second data representative of the variance σ j 2 of said decision signal levels; and (b) calculating the probability of error in recovered data symbols at the output of said decoder in accordance with said first and second data so as to obtain said quality of said communication link.

Claim 16

Dependent Claim 16 words

A method according to claim 13, wherein said communication link is a spread spectrum communication link.

Claim 17

Dependent Claim 55 words

A method according to claim 13, wherein said first and second data are derived in response to signals conveyed over a selected communication link between terminal stations via said transponder, said conveyed signals containing data symbols having a symbol data rate other than the data rate associated with symbols transmitted from said prescribed transmitting station.

Claim 18

Dependent Claim 35 words

A method according to claim 15, wherein step (b) includes the step of compensating said first and second data in accordance with variations in the gain of the receiver at said prescribed receiving station j.

Claim 19

Dependent Claim 40 words

A method according to claim 13, wherein step (a) comprises deriving a first signal representative of the signal power in a received signal equivalent to continuous signal power, and a second signal representative of noise density received from said transponder.

Claim 20

Dependent Claim 58 words

A method according to claim 17, wherein step (a) includes the steps of (a1) processing said first signal in accordance with preselected uplink parameters associated with said selected communication link to obtain said first data, and (a2) processing said second signal in accordance with preselected downlink parameters associated with said selected communication link to obtain said second data.

Claim 21

Dependent Claim 162 words

For use in a communications system wherein a plurality of stations communicate with one another via a transponder remote with respect to said stations, an apparatus for measuring the performance of a communication link between a prescribed transmitting station, said transponder and a prescribed receiving station comprising, at a first selected one of said stations: first means for receiving signals transmitted from a second selected one of said stations via said transponder; second means for deriving, from the signal received by said first means, a first output signal representative of a prescribed characteristic of said transponder at a symbol rate associated with signals transmitted by said prescribed transmitting station, and a second output signal representative of a prescribed characteristic of said received signals; and third means for processing said first and second output signals derived by said second means in accordance with preselected parameters associated with said communication link so as to obtain a measurement of the performance of said communication link.

Claim 22

Dependent Claim 162 words

For use in a communications system wherein a plurality of stations communicate with one another via a transponder remote with respect to said stations, an apparatus for measuring the performance of a communication link between a prescribed transmitting station, said transponder and a prescribed receiving station comprising, at a first selected one of said stations: first means for receiving signals transmitted from a second selected one of said stations via said transponder; second means for deriving, from the signal received by said first means, a first output signal representative of a prescribed characteristic of said transponder at a symbol rate associated with signals transmitted by said prescribed transmitting station, and a second output signal representative of a prescribed characteristic of said received signals; and third means for processing said first and second output signals derived by said second means in accordance with preselected parameters associated with said communication link so as to obtain a measurement of the performance of said communication link.

Claim 23

Dependent Claim 36 words

An apparatus according to claim 19, wherein said prescribed characteristic of said transponder corresponds to the effective gain of said transponder and said prescribed characteristic of said received signals corresponds to the effective transponder noise density.

Claim 24

Dependent Claim 13 words

An apparatus according to claim 20, wherein said transponder comprises a satellite transponder.

Claim 25

Dependent Claim 22 words

An apparatus according to claim 20, wherein said first and second selected ones of said stations correspond to the same selected station.

Claim 26

Dependent Claim 36 words

An apparatus according to claim 22, wherein said symbol rate of signals transmitted from and received by said same selected station is different from the symbol rate associated with signals transmitted by said prescribed transmitting station.

Claim 27

Dependent Claim 38 words

An apparatus according to claim 20, wherein said preselected parameters include preestablished uplink parameters of a communication link between said prescribed transmitting station and said transponder, and preestablished downlink parameters between said transponder and said prescribed receiving station.

Claim 28

Dependent Claim 78 words

An apparatus according to claim 20, wherein a receiving station contains a decoder for recovering data symbols in accordance with data decision signal levels and wherein said third means includes means for deriving first data μ ij representative of the mean value of decision signal levels on symbols transmitted from said prescribed transmitting station i and received at said prescribed receiving station j and second data representative of the variance σ 2 j of said decision signal levels.

Claim 29

Dependent Claim 72 words

An apparatus according to claim 25, wherein said prescribed receiving station j includes an error correction decoder for correcting errors in data symbols contained in signals received at said receiving station j transmitted over said communication link from said prescribed transmitting station i, and said third means includes means for of calculating the probability of error at the output of said error correction decoder in accordance with said first and second data.

Claim 30

Dependent Claim 35 words

An apparatus according to claim 26, wherein said third means includes means for compensating said first and second data in accordance with variations in the gain of the receiver at said prescribed receiving station j.

Claim 31

Dependent Claim 44 words

An apparatus according to claim 26, wherein said second means includes means for deriving a first signal representative of the signal power in the received signal equivalent to continuous wave signal power and a second signal representative of noise density received from said transponder.

Claim 32

Dependent Claim 98 words

An apparatus according to claim 28, wherein said second means includes means for processing said first signal in accordance with preselected uplink parameters associated with the link between said second selected one of said stations and said transponder and in accordance with preselected downlink parameters associated with the link between said transponder and said first selected one of said stations to obtain said first output signal, and processing said second signal in accordance with preselected downlink parameters associated with the link between said transponder and said first selected one of said stations to obtain said second output signal.

Claim 33

Dependent Claim 22 words

An apparatus according to claim 19, wherein signals received at said first selected one of said stations are spread spectrum encoded signals.

Claim 34

Dependent Claim 168 words

For use in a communications system wherein a plurality of stations communicate with one another via a transponder remote with respect to said stations, an apparatus measuring the quality of a communication link between a prescribed transmitting station i, said transponder and a prescribed receiving station j, said prescribed receiving stations j containing a decoder for recovering data symbols, transmitted by said prescribed transmitting station i, in accordance with data symbol decision signal levels, said apparatus comprising first means for deriving first data μ ij representative of the mean value of decision signal levels on symbols transmitted from said prescribed transmitting station i and received at said prescribed receiving station j, and second data representative of the variance σ 2 j of said decision signal levels; and second means for calculating the probability of error in recovered data symbols at the output of said decoder in accordance with said first and second data derived by said first means so as to obtain said quality of said communication link.

Claim 35

Dependent Claim 168 words

For use in a communications system wherein a plurality of stations communicate with one another via a transponder remote with respect to said stations, an apparatus measuring the quality of a communication link between a prescribed transmitting station i, said transponder and a prescribed receiving station j, said prescribed receiving stations j containing a decoder for recovering data symbols, transmitted by said prescribed transmitting station i, in accordance with data symbol decision signal levels, said apparatus comprising first means for deriving first data μ ij representative of the mean value of decision signal levels on symbols transmitted from said prescribed transmitting station i and received at said prescribed receiving station j, and second data representative of the variance σ 2 j of said decision signal levels; and second means for calculating the probability of error in recovered data symbols at the output of said decoder in accordance with said first and second data derived by said first means so as to obtain said quality of said communication link.

Claim 36

Dependent Claim 16 words

An apparatus according to claim 31, wherein said communication link is a spread spectrum communication link.

Claim 37

Dependent Claim 59 words

An apparatus according to claim 31, wherein said first and second data are derived by said first means in response to signals conveyed over a selected communication link between terminal stations via said transponder, said conveyed signals containing data symbols having a symbol data rate other than the data rate associated with symbols transmitted from said prescribed transmitting station.

Claim 38

Dependent Claim 35 words

An apparatus according to claim 33, wherein said second means includes means for compensating said first and second data in accordance with variations in the gain of the receiver at said prescribed receiving station j.

Claim 39

Dependent Claim 42 words

An apparatus according to claim 31, said first means includes means for deriving a first signal representative of the signal power in a received signal equivalent to continuous signal power, and a second signal representative of noise density received from said transponder.

Claim 40

Dependent Claim 56 words

An apparatus according to claim 35, wherein said first means includes means for processing said first signal in accordance with preselected uplink parameters associated with said selected communication link to obtain said first data, and processing said second signal in accordance with preselected downlink parameters associated with said selected communication link to obtain said second data.

Annuity Stage	Window Opens	Payment Deadline	Surcharge Period Until	Estimated Fee	Status
3.5 Years (Year 4)	1990-03-23	1990-09-22	1991-03-24	$2000.00	Window Closed / Lapsed
7.5 Years (Year 8)	1994-03-23	1994-09-22	1995-03-24	$3760.00	Window Closed / Lapsed
11.5 Years (Year 12)	1998-03-23	1998-09-22	1999-03-24	$7700.00	Window Closed / Lapsed

Performance monitoring of antijam satellite communication network

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