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- Inventor(s):
- James L. Massey
- Patent Number:
- US 3402393
- Description:
Digital error correcting coding techniques involving the sensing of conditions under which the decoder is operating. In one aspect a monitoring device counts the ones in the decoding decision and in certain parity checks corrected by those decisions. In another aspect the code is supplemented such that one actual decoding error can create a number of apparent errors or ones, which enables early detection of conditions beyond the capability of the decoder. In another aspect fades are detected …
- Date Issued:
- 1968-09-17
- Record Visibility:
- Public
- Title
- Error detection and correction in signal transmission by use of convolution codes
- Description
- Digital error correcting coding techniques involving the sensing of conditions under which the decoder is operating. In one aspect a monitoring device counts the ones in the decoding decision and in certain parity checks corrected by those decisions. In another aspect the code is supplemented such that one actual decoding error can create a number of apparent errors or ones, which enables early detection of conditions beyond the capability of the decoder. In another aspect fades are detected in combination with a decoding logic capable of acting upon the whole set or any group of nonfaded elements in the decoding set.
- Creator
- James L. Massey
- Publisher
- United States Patent and Trademark Office
- Language
- English
- Resource Type
- Patent
-
- Inventor(s):
- Jimmy K. Omura, James L. Massey
- Patent Number:
- US 4587627
- Description:
Elements of the finite field GF(2.sup.m) are represented by a vector of m binary digits in such a way that multiplication can be performed by using the same logic function to compute each binary component of the product of two elements, squaring can be performed by logic circuitry that rotates the vector representing the element to be squared, and addition can be performed by logic circuitry that forms the modulo-two sum of the corresponding components of the two vectors representing the elem…
- Date Issued:
- 1986-05-06
- Record Visibility:
- Public
- Title
- Computational method and apparatus for finite field arithmetic
- Description
- Elements of the finite field GF(2.sup.m) are represented by a vector of m binary digits in such a way that multiplication can be performed by using the same logic function to compute each binary component of the product of two elements, squaring can be performed by logic circuitry that rotates the vector representing the element to be squared, and addition can be performed by logic circuitry that forms the modulo-two sum of the corresponding components of the two vectors representing the elements to be summed.
- Creator
- Jimmy K. Omura, James L. Massey
- Publisher
- United States Patent and Trademark Office
- Language
- English
- Resource Type
- Patent
-
- Inventor(s):
- James L. Massey, Jimmy K. Omura
- Patent Number:
- US 4567600
- Description:
A private message of m bits is conveyed from its sender to its receiver by transmission of a public message of m bits, transmission of a public reply of m bits, and another transmission of a public message of m bits such that only the intended receiver can easily recover the private message from the three public messages. This private message now available to both the sender and intended receiver also allows all subsequent private messages between these two points to require only one public m…
- Date Issued:
- 1986-01-28
- Record Visibility:
- Public
- Title
- Method and apparatus for maintaining the privacy of digital messages conveyed by public transmission
- Description
- A private message of m bits is conveyed from its sender to its receiver by transmission of a public message of m bits, transmission of a public reply of m bits, and another transmission of a public message of m bits such that only the intended receiver can easily recover the private message from the three public messages. This private message now available to both the sender and intended receiver also allows all subsequent private messages between these two points to require only one public message for each private message while maintaining the property that only the intended receiver of each message can easily recover the private message for each public message.
- Creator
- James L. Massey, Jimmy K. Omura
- Publisher
- United States Patent and Trademark Office
- Language
- English
- Resource Type
- Patent
-
- Inventor(s):
- James L. Massey
- Patent Number:
- US 3429334
- Description:
Device for correcting or detecting errors in transmission of signal information, having an information signal memory, an adder for forming redundancy signals from connections between the adder and the memory in accordance with a convolutional code, the device constructed to enable backward or forward decoding of the message.
- Date Issued:
- 1969-04-15
- Record Visibility:
- Public
- Title
- Processing signal information
- Description
- Device for correcting or detecting errors in transmission of signal information, having an information signal memory, an adder for forming redundancy signals from connections between the adder and the memory in accordance with a convolutional code, the device constructed to enable backward or forward decoding of the message.
- Creator
- James L. Massey
- Publisher
- United States Patent and Trademark Office
- Language
- English
- Resource Type
- Patent
-
- Inventor(s):
- James L. Massey
- Patent Number:
- US 3303333
- Description:
This invention relates to methods of and aparatus for processing signal information and, more particularly, to the correcting and/or detecting of signal errors or other changes, as produced in transmission.
- Date Issued:
- 1967-02-07
- Record Visibility:
- Public
- Title
- Error detection and correction system for convolutional codes
- Description
- This invention relates to methods of and aparatus for processing signal information and, more particularly, to the correcting and/or detecting of signal errors or other changes, as produced in transmission.
- Creator
- James L. Massey
- Publisher
- United States Patent and Trademark Office
- Language
- English
- Resource Type
- Patent
-
- Inventor(s):
- James L. Massey
- Patent Number:
- EP 0486834B1
- Description:
In a multiple access method for the simultaneous exchange of several data streams ({B.sub.1,m }, {B.sub.2,m }, {B.sub.3,m }) among several participants of a transmission system, various data streams ({B.sub.1,m }, {B.sub.2,m }, {B.sub.3,m }) with the same spread sequence (s[.]) are expanded to a corresponding DSSS signal ({B.sub.1,m s[.]}, {B.sub.2,m s[.]}, {B.sub.3,m s[.]}. During transmission, the various DSSS signals ({B.sub.1,m s[.]}, {B.sub.2,m s[.]}, {B.sub.3,m s[.]}) are heterodyned to…
- Date Issued:
- 1990-11-22
- Record Visibility:
- Public
- Title
- Code time division Multiple Access System
- Description
- In a multiple access method for the simultaneous exchange of several data streams ({B.sub.1,m }, {B.sub.2,m }, {B.sub.3,m }) among several participants of a transmission system, various data streams ({B.sub.1,m }, {B.sub.2,m }, {B.sub.3,m }) with the same spread sequence (s[.]) are expanded to a corresponding DSSS signal ({B.sub.1,m s[.]}, {B.sub.2,m s[.]}, {B.sub.3,m s[.]}. During transmission, the various DSSS signals ({B.sub.1,m s[.]}, {B.sub.2,m s[.]}, {B.sub.3,m s[.]}) are heterodyned to a single incoming signal. For detecting the various data streams in a receiver, the incoming signal is filtered in a filter that is inverse with respect to the joint spread sequence (s[.]). In order to permit reliable detection, heterodyning takes place in each case so that the spread sequence intervals pertaining to different data streams are chronologically shifted with respect to one another by a given minimum value (delta.sub.-- T). The invention provides a multiple access method combining therein the advantages of TDMA and CDMA. In particular, an almost complete separation of the users is possible without requiring the precision of synchronization customary in case of TDMA.
- Creator
- James L. Massey
- Publisher
- European Patent Office
- Language
- German, English, French
- Resource Type
- Patent
-
- Inventor(s):
- James L. Massey, Xuejia Lai
- Patent Number:
- US 5214703
- Description:
The device (12) comprises nine encryption stages (61.1, 61.2, 69), the first eight of which are constructed identically. It further comprises a key subblock generation unit (63), an input unit (21), and an output unit (79). It serves for the block-by-block encryption of a plaintext (X) proceeding from a message source (11) into a ciphertext (Y) to be delivered on a transmission line (13), wherein a secret key block (Z) is inputted beforehand via a secure channel 17. The encryption is effected…
- Date Issued:
- 1993-05-25
- Record Visibility:
- Public
- Title
- Device for the conversion of a digital block and use of same
- Description
- The device (12) comprises nine encryption stages (61.1, 61.2, 69), the first eight of which are constructed identically. It further comprises a key subblock generation unit (63), an input unit (21), and an output unit (79). It serves for the block-by-block encryption of a plaintext (X) proceeding from a message source (11) into a ciphertext (Y) to be delivered on a transmission line (13), wherein a secret key block (Z) is inputted beforehand via a secure channel 17. The encryption is effected in a step-by-step and parallel manner for four subblocks (X.sub.1 -X.sub.4 ; W.sub.11 -W.sub.14 ; W.sub.21 -W.sub.24 ; W.sub.81 -W.sub.84 ; Y.sub.1 -Y.sub.4). Every encryption stage (61.1, 61.2, 69) comprises four first inputs (25-28; 35-38), six and four second inputs (29, 30, 32, 33, 49, 52; 129, 130, 132, 133), respectively, and four outputs (75-78). A total of fifty-two key subblocks (Z.sub.1 -Z.sub.52) which are formed from the key block (Z) are connected to the second inputs. The device (12) can also serve, without being altered, for the decryption of an incoming ciphertext (Y). Different key subblocks need only be connected to the second inputs for this purpose.
- Creator
- James L. Massey, Xuejia Lai
- Publisher
- United States Patent and Trademark Office
- Language
- English
- Resource Type
- Patent
-
- Inventor(s):
- Thomas Schaub, James L. Massey
- Patent Number:
- US 4506372
- Description:
In an apparatus and a method for recognizing the start of a noise-corrupted received telegram signal, and wherein the telegram signal consists of an information-containing sequence of bits ahead of the telegram signal, thereafter transmitting an intermediate sequence of bits following the preliminary sequence, but still ahead of the telegram signal, wherein the preliminary and the intermediate sequences are correlated with different parts of the preliminary and of the intermediate sequence in…
- Date Issued:
- 1985-03-19
- Record Visibility:
- Public
- Title
- Method and apparatus for recognizing in a receiver the start of a telegram signal consisting of a bit impulse sequence
- Description
- In an apparatus and a method for recognizing the start of a noise-corrupted received telegram signal, and wherein the telegram signal consists of an information-containing sequence of bits ahead of the telegram signal, thereafter transmitting an intermediate sequence of bits following the preliminary sequence, but still ahead of the telegram signal, wherein the preliminary and the intermediate sequences are correlated with different parts of the preliminary and of the intermediate sequence in a pre-arranged manner, and detecting the pre-arranged manner so as to positively signal termination of the intermediate sequence; recognition of the start of the telegram signal is thereby ensured.
- Creator
- Thomas Schaub, James L. Massey
- Publisher
- United States Patent and Trademark Office
- Language
- English
- Resource Type
- Patent
-
- Inventor(s):
- James L. Massey
- Patent Number:
- US 5170412
- Description:
In a multiple access method for the simultaneous exchange of several data streams ({B.sub.1,m }, {B.sub.2,m }, {B.sub.3,m }) among several participants of a transmission system, various data streams ({B.sub.1,m }, {B.sub.2,m }, {B.sub.3,m }) with the same spread sequence (s[.]) are expanded to a corresponding DSSS signal ({B.sub.1,m s[.]}, {B.sub.2,m s[.]}, {B.sub.3,m s[.]}. During transmission, the various DSSS signals ({B.sub.1,m s[.]}, {B.sub.2,m s[.]}, {B.sub.3,m s[.]}) are heterodyned to…
- Date Issued:
- 1992-12-08
- Record Visibility:
- Public
- Title
- Multiple access method
- Description
- In a multiple access method for the simultaneous exchange of several data streams ({B.sub.1,m }, {B.sub.2,m }, {B.sub.3,m }) among several participants of a transmission system, various data streams ({B.sub.1,m }, {B.sub.2,m }, {B.sub.3,m }) with the same spread sequence (s[.]) are expanded to a corresponding DSSS signal ({B.sub.1,m s[.]}, {B.sub.2,m s[.]}, {B.sub.3,m s[.]}. During transmission, the various DSSS signals ({B.sub.1,m s[.]}, {B.sub.2,m s[.]}, {B.sub.3,m s[.]}) are heterodyned to a single incoming signal. For detecting the various data streams in a receiver, the incoming signal is filtered in a filter that is inverse with respect to the joint spread sequence (s[.]). In order to permit reliable detection, heterodyning takes place in each case so that the spread sequence intervals pertaining to different data streams are chronologically shifted with respect to one another by a given minimum value (delta.sub.-- T). The invention provides a multiple access method combining therein the advantages of TDMA and CDMA. In particular, an almost complete separation of the users is possible without requiring the precision of synchronization customary in case of TDMA.
- Creator
- James L. Massey
- Publisher
- United States Patent and Trademark Office
- Language
- German, English
- Resource Type
- Patent
-
- Inventor(s):
- James L. Massey
- Patent Number:
- US 3566352
- Description:
Error correction in convolutionally coded messages, using a plurality of information digit streams and a single parity digital stream with each information digit being included as a component in the defining summation for exactly two parity digits spaced apart by a certain number of time intervals (a time interval being defined to include a digit from each stream), the time interval spacing between the two parity digits being the same for each information digit in a given stream but different…
- Date Issued:
- 1971-02-23
- Record Visibility:
- Public
- Title
- Error correction in coded messages
- Description
- Error correction in convolutionally coded messages, using a plurality of information digit streams and a single parity digital stream with each information digit being included as a component in the defining summation for exactly two parity digits spaced apart by a certain number of time intervals (a time interval being defined to include a digit from each stream), the time interval spacing between the two parity digits being the same for each information digit in a given stream but different for each stream, the spacing being longer than the design correctable burst length but shorter than twice the design correctable burst length for all but at most one of the information digit streams.
- Creator
- James L. Massey
- Publisher
- United States Patent and Trademark Office
- Language
- English
- Resource Type
- Patent
-
- Inventor(s):
- James L. Massey
- Patent Number:
- US 3500320
- Description:
Bursts of errors in convolutionally coded messages are corrected by a decoder in which a parity checking circuit determines whether selected syndrome digits which lie within the constraint length of the code form a codeword in a linear block code having as its codewords the set of all patterns of said selected syndrome digits that are consistent with any error burst pattern confined to the beginning of said constraint length and upon the presence of such a codeword, error detecting and correc…
- Date Issued:
- 1970-03-10
- Record Visibility:
- Public
- Title
- Error correcting means for digital transmission systems
- Description
- Bursts of errors in convolutionally coded messages are corrected by a decoder in which a parity checking circuit determines whether selected syndrome digits which lie within the constraint length of the code form a codeword in a linear block code having as its codewords the set of all patterns of said selected syndrome digits that are consistent with any error burst pattern confined to the beginning of said constraint length and upon the presence of such a codeword, error detecting and correction circuitry becomes operative.
- Creator
- James L. Massey
- Publisher
- United States Patent and Trademark Office
- Language
- English
- Resource Type
- Patent
-
- Inventor(s):
- Abhay Kumar, Paul W. Futa, Jr., Steven F. Fisher
- Patent Number:
- US 6328056 B2
- Description:
An unbalance compensated bypass valve (14, 21, 23) for a gas turbine engine fuel supply system is responsive to the fuel pressure differential across a fuel metering valve (15) to open and close a bypass orifice (37, 39, 41; 89, 91, 93; 99, 101, 103). The bypass valve (14, 21, 23) selectively supplies high fuel pressure to a compensating cavity (45, 95, 120) providing a counterbalancing force against an annular area (47, 97, 124) of the bypass valve piston (34, 81, 83, 111, 112) to compensate…
- Date Issued:
- 2001-12-11
- Record Visibility:
- Public
- Title
- Proportional bypass valve with dual variable orifice
- Description
- An unbalance compensated bypass valve (14, 21, 23) for a gas turbine engine fuel supply system is responsive to the fuel pressure differential across a fuel metering valve (15) to open and close a bypass orifice (37, 39, 41; 89, 91, 93; 99, 101, 103). The bypass valve (14, 21, 23) selectively supplies high fuel pressure to a compensating cavity (45, 95, 120) providing a counterbalancing force against an annular area (47, 97, 124) of the bypass valve piston (34, 81, 83, 111, 112) to compensate for increased restorative forces of a helical reference spring (57, 112, 125) as that spring is collapsed as well as to compensate for other unbalance conditions within the valve (14, 21, 23). The compensating cavity may include a variable orifice inlet (37, 39, 41), (99, 101, 103), or (89, 91, 93) and a variable orifice outlet (105, 107, 109) or the inlet orifice may be variable while the outlet orifice (43, 96, 99) is fixed. The piston (34) or housing (100) may include additional sidewall openings (69, 70, 71) or (92, 94) which function during a "shut-off" condition to divert all fuel flow from the metering valve (15) inlet back to a fuel pump (13) inlet. The piston (34) may also include further sidewall openings (73, 75) which provide a controlled fuel leakage from a bypass valve inlet (25) to the bypass valve pressure sensing port (29).
- Creator
- Abhay Kumar, Paul W. Futa, Jr., Steven F. Fisher
- Publisher
- United States Patent and Trademark Office
- Language
- English
- Rights
- http://creativecommons.org/publicdomain/zero/1.0/
- Resource Type
- Patent