1. A data transmission apparatus, comprising:
a low density parity check (LDPC) code (LDPCC) coder for coding a plurality of codes having various rates, wherein the plurality of codes have an identical code blocklength and different code rates, and at least one row of a higher-rate LDPC matrix is obtained by combining a plurality of rows of a lower-rate LDPC matrix with the identical code blocklength as the higher-rate LDPC matrix.
2. The apparatus of claim 1, wherein the coder is an encoder for encoding the plurality of codes.
3. The apparatus of claim 1, wherein the coder is a decoder for decoding the plurality of codes.
4. The apparatus of claim 1, wherein the lower-rate LDPC matrix comprises a mother LDPC matrix.
5. The apparatus of claim 4, wherein the mother LDPC matrix has a block structure that is comprised of a plurality of square sub-matrices, wherein each square sub-matrix is either a zero sub-matrix, a structured sub-matrix, or a bi-diagonal sub-matrix.
6. The apparatus of claim 5, wherein at least one structured sub-matrix is produced by cyclically shifting the columns of an identity matrix.
7. The apparatus of claim 5, wherein at least one structured sub-matrix is a superposition of a plurality of cyclically-shifted identity matrices.
8. The apparatus of claim 5, wherein the mother LDPC matrix includes a sub-matrix with a block-lower-triangular structure.
9. The apparatus of claim 4, wherein the mother LDPC matrix includes a sub-matrix with a lower-triangular structure.
10. The apparatus of claim 1, wherein the lower-rate LDPC matrix is a square matrix.
11. The apparatus of claim 1, wherein, for at least two of the codes having the identical code blocklength and different rates, associated LDPCC matrices are jointly designed to have favorable graphical properties that help lower an error floor.
12. The apparatus of claim 1, wherein for at least two of the codes having the identical code blocklength and different rates, associated LDPCC matrices are jointly designed to have favorable graphical properties that help lower an error floor and are designed to prevent small stopping sets.
13. The apparatus of claim 1, wherein for at least two of the codes having the identical code blocklength and different rates, associated LDPCC matrices are jointly designed to have favorable graphical properties that help lower an error floor and are designed to prevent short cycles.
14. The apparatus of claim 1, wherein an LDPCC matrix for a second code is obtained from an LDPCC matrix of a first code by combining groups of rows of the LDPCC matrix of the first code and deleting at least one column of the LDPCC matrix of the first code.
15. The apparatus of claim 1, wherein groups of at least three rows of the lower-rate LDPC matrix are combined to produce a single row in the higher-rate LDPC matrix.
16. The apparatus of claim 1, wherein the lower-rate LDPC matrix is chosen so that other desired rates are obtained by combining equal-size groups of rows of the matrix.
17. The apparatus of claim 1, wherein the lower-rate LDPC matrix corresponds to a rate that is not used by the system.
18. The apparatus of claim 1, wherein, to produce the higher-rate LDPC matrix, at least one edge is deleted or added to a bi-partite graph produced by the matrix resulting from the combining of the rows.
19. A method of data transmission, comprising:
coding a plurality of codes having various rates using a low density parity check (LDPC) code (LDPCC) coder, wherein the plurality of codes have an identical code blocklength and different code rates, and at least one row of a higher-rate LDPC matrix is obtained by combining a plurality of rows of a lower-rate LDPC matrix with the identical code blocklength as the higher-rate LDPC matrix.
20. The method of claim 19, wherein the coder is an encoder for encoding the plurality of codes.
21. The method of claim 19, wherein the coder is a decoder for decoding the plurality of codes.
22. The method of claim 19, wherein the lower-rate LDPC matrix comprises a mother LDPC matrix.
23. The method of claim 22, wherein the mother LDPC matrix is a block structure that is comprised of a plurality of square sub-matrices, wherein each square sub-matrix is either a zero sub-matrix, a structured sub-matrix, or a bi-diagonal sub-matrix.
24. The method of claim 23, wherein at least one structured sub-matrix is produced by cyclically shifting the columns of an identity matrix.
25. The method of claim 23, wherein at least one structured sub-matrix is a superposition of a plurality of cyclically-shifted identity matrices.
26. The method of claim 23, wherein the mother LDPC matrix includes a sub-matrix with a block-lower-triangular structure.
27. The method of claim 22, wherein the mother LDPC matrix includes a sub-matrix with a lower-triangular structure.
28. The method of claim 19, wherein the lower-rate LDPC matrix is a square matrix.
29. The method of claim 19, wherein, for at least two of the codes having the identical code blocklength and different rates, associated LDPCC matrices are jointly designed to have favorable graphical properties that help lower an error floor.
30. The method of claim 19, wherein for at least two of the codes having the identical code blocklength and different rates, associated LDPCC matrices are jointly designed to have favorable graphical properties that help lower an error floor and are designed to prevent small stopping sets.
31. The method of claim 19, wherein for at least two of the codes having the identical code blocklength and different rates, associated LDPCC matrices are jointly designed to have favorable graphical properties that help lower an error floor and are designed to prevent short cycles.
32. The method of claim 19, wherein an LDPCC matrix for a second code is obtained from an LDPCC matrix of a first code by combining groups of rows of the LDPCC matrix of the first code and deleting at least one column of the LDPCC matrix of the first code.
33. The method of claim 19, wherein groups of at least three rows of the lower-rate LDPC matrix are combined to produce a single row in the higher-rate LDPC matrix.
34. The method of claim 19, wherein the lower-rate LDPC matrix is chosen so that other desired rates are obtained by combining equal-size groups of rows of the matrix.
35. The method of claim 19, wherein the lower-rate LDPC matrix corresponds to a rate that is not used by the system.
36. The method of claim 19, wherein, to produce the higher-rate LDPC matrix, at least one edge is deleted or added to a bi-partite graph produced by the matrix resulting from the combining of the rows.
The claims below are in addition to those above.
All refrences to claim(s) which appear below refer to the numbering after this setence.
1. An eye surgery system including an imaging system, wherein the imaging system comprises:
a data memory configured to store an orientation value:
an image memory configured to store a first image of an eye under surgery recorded prior to the surgery;
a camera configured to record a second image of the eye under surgery during the surgery;
an image processing device configured to determine an orientation value based on the first and second images; and
a display device configured to generate a representation of a marker based on the determined orientation value.
2. The eye surgery system according to claim 1, wherein the imaging system further comprises a stand configured to mount the camera at a distance from the eye under surgery, wherein the stand comprises a plurality of joints allowing a displacement of the first camera in three spatial directions orthogonal to each other.
3. The eye surgery system according to claim 1, wherein the imaging system comprises a surgical microscope having an imaging beam path, and wherein the camera is positioned in the imaging beam path of the camera.
4. The eye surgery system according to claim 3, wherein the display device includes an ocular positioned in the imaging beam path of the surgical microscope.
5. The eye surgery system according to claim 4, wherein the display device further includes an image projector configured to project the representation of the marker into the beam path towards the ocular.
6. The eye surgery system according to claim 1, wherein the display device comprises at least one of a head-mounted display device and a monitor.
7. The eye surgery system according to claim 1, wherein the display device comprises an interface configured to input the first image to the image memory.
8. The eye surgery system according to claim 1, further including a diagnostic system, wherein the diagnostic system comprises:
a camera configured to record the first image of the eye under surgery prior to the surgery; and
an interface configured to output the first image.
9. The eye surgery system according to claim 8, wherein the diagnostic system is configured to determine at least one orientation of an eye astigmatism of the eye, and wherein the diagnostic system comprises an interface configured to output an orientation value representing the determined orientation of the astigmatism.
10. The eye surgery system according to claim 8, wherein the camera of the diagnostic system comprises a detector having an array of image elements, and wherein a number of the image elements of the diagnostic system is greater than or equal to a number of image elements of the detector of the camera of the imaging system.
11. A method of preparing a surgery on an eye, wherein the method comprises:
recording a first image of an eye of a patient;
recording a second image of the eye;
determining an orientation based on the first recorded image and the second recorded image; and
generating a representation of a marker based on the determined orientation.
12. The method according to claim 11, wherein the first image of the eye is recorded when a head of the patient is in an upright position.
13. The method according to claim 11, wherein the second image of the eye is recorded when the head of the patient is in a lying position.
14. The method according to claim 11, further comprising generating a representation of the eye by optically imaging the eye, and projecting the representation of the marker into the representation of the eye.
15. The method according to claim 11 further comprising generating a representation of the eye by displaying the second image.
16. The method according to claim 11 wherein the recording of the second image, the determining of the orientation and the generating of the representation of the marker are carried out repeatedly after the first image of the eye has been recorded.
17. The method according to claim 11, further comprising determining an orientation of an eye astigmatism of the eye, wherein the generating of the representation of the marker is further based on the determined orientation of the eye astigmatism.
18. A method of performing an eye surgery, wherein the method comprises
recording a first image of an eye of a patient;
recording a second image of the eye;
determining an orientation based on the first recorded image and the second recorded image; and
generating a representation of a marker based on the determined orientation; wherein the first image is recorded prior to the surgery and the second image is recorded during the surgery.
19. The method according to claim 18, further comprising orienting an intraocular lens relative to the eye based on the representation of the marker.
20. The method according to claim 11, further comprising applying at least one marker on the eye before recording of the first image.
21. The method according to claim 11 further comprising measuring of optical characteristics of the eye of the patient and manufacturing an intraocular lens based on the measured optical characteristics.
22. The method according to claim 21, wherein the second image is recorded after the manufacturing of the intraocular lens.