Low complexity communication device employing in-place constructed LDPC (low density parity check) code
View Patent ↗Low complexity communication device employing in-place constructed LDPC (Low Density Parity Check) code. Intelligent design of LDPC codes having similar characteristics there between allows for a very efficient hardware implementation of a communication device that is operative to perform decoding of more than one type of LDPC coded signals. A common basis of decoder hardware (e.g., decoder circuitry) is employed when decoding all of the various types of LDPC coded signals that such a communication device can decode. However, all of the decoder hardware is only employed to decode signals corresponding to the lowest code rate LDPC code supported by the communication device. A first subset of the decoder hardware is employed to decode signals corresponding to the second to lowest code rate LDPC code, a second subset (being less than the first subset) is employed to decode signals corresponding to the third to lowest code rate LDPC code, etc.
1. An apparatus, comprising:
an LDPC (Low Density Parity Check) decoder circuitry for employing a plurality of configurations of a superimposed LDPC matrix for respectively decoding a plurality of LDPC coded signals, the superimposed LDPC matrix corresponding to LDPC codes of an in-place LDPC code set, wherein:
each of the LDPC codes having a respective code rate; and
each of the LDPC codes having a respective LDPC matrix; and
a switching module for, based on a selected LDPC code of the in-place LDPC code set, selectively enabling or disabling sub-matrices of the superimposed LDPC matrix for within each of the plurality of configurations; and wherein:
when the superimposed LDPC matrix being within a first of the plurality of configurations, the LDPC decoder circuitry decoding a first of the plurality of LDPC coded signals thereby generating a first plurality of information bit estimates; and
when the superimposed LDPC matrix being within a second of the plurality of configurations, the LDPC decoder circuitry decoding a second of the plurality of LDPC coded signals thereby generating a second plurality of information bit estimates.
2. The apparatus of claim 1 , wherein:
a first LDPC code of the in-place LDPC code set corresponding to a first code rate and a first LDPC matrix; and
a second LDPC code of the in-place LDPC code set corresponding to a second code rate, being higher than the first code rate, and corresponding to a second LDPC matrix, having fewer rows than the first LDPC matrix.
3. The apparatus of claim 2 , wherein:
the first LDPC matrix and the second LDPC matrix each include at least one common sub-matrix row.
4. The apparatus of claim 2 , wherein:
the first LDPC matrix and the second LDPC matrix each include at least one common sub-matrix column.
5. The apparatus of claim 2 , wherein:
a third LDPC code of the in-place LDPC code set corresponding to a third code rate, being higher than the second code rate, and corresponding to a third LDPC matrix, having fewer rows than the second LDPC matrix.
6. The apparatus of claim 1 , wherein:
the superimposed LDPC matrix being partitioned into a systematic matrix portion and a parity matrix portion; and
the parity matrix portion having a lower triangular form.
7. The apparatus of claim 1 , wherein:
the switching module switching between the first of the plurality of configurations and the second of the plurality of configurations in accordance with a predetermined sequence.
8. The apparatus of claim 1 , wherein:
the switching module switching between the first of the plurality of configurations and the second of the plurality of configurations based on a change in at least one operating condition of the apparatus or of a communication system in which the apparatus being implemented.
9. The apparatus of claim 1 , wherein:
each of the LDPC codes of the in-place LDPC code set being systematic.
10. The apparatus of claim 1 , wherein:
the apparatus being a communication device; and
the communication device being operative within at least one of a satellite communication system, a wireless communication system, a wired communication system, and a fiber-optic communication system.
11. An apparatus, comprising:
an LDPC (Low Density Parity Check) decoder circuitry for employing a plurality of configurations of a superimposed LDPC matrix for respectively decoding a plurality of LDPC coded signals, the superimposed LDPC matrix corresponding to LDPC codes of an in-place LDPC code set, wherein:
each of the LDPC codes having a respective code rate;
each of the LDPC codes having a respective LDPC matrix;
each of the LDPC codes being systematic; and
the superimposed LDPC matrix being partitioned into a systematic matrix portion and a parity matrix portion such that the parity matrix portion having a lower triangular form; and
a switching module for, based on a selected LDPC code of the in-place LDPC code set, selectively enabling or disabling sub-matrices of the superimposed LDPC matrix for within each of the plurality of configurations; and wherein:
when the superimposed LDPC matrix being within a first of the plurality of configurations, the LDPC decoder circuitry decoding a first of the plurality of LDPC coded signals thereby generating a first plurality of information bit estimates;
when the superimposed LDPC matrix being within a second of the plurality of configurations, the LDPC decoder circuitry decoding a second of the plurality of LDPC coded signals thereby generating a second plurality of information bit estimates;
a first LDPC code of the in-place LDPC code set corresponding to a first code rate and a first LDPC matrix; and
a second LDPC code of the in-place LDPC code set corresponding to a second code rate, being higher than the first code rate, and corresponding to a second LDPC matrix, having fewer rows than the first LDPC matrix.
12. The apparatus of claim 11 , wherein:
the switching module switching between the first of the plurality of configurations and the second of the plurality of configurations in accordance with a predetermined sequence.
13. The apparatus of claim 11 , wherein:
the switching module switching between the first of the plurality of configurations and the second of the plurality of configurations based on a change in at least one operating condition of the apparatus or of a communication system in which the apparatus being implemented.
14. The apparatus of claim 11 , wherein:
the apparatus being a communication device; and
the communication device being operative within at least one of a satellite communication system, a wireless communication system, a wired communication system, and a fiber-optic communication system.
15. A method for operating a communication device, the method comprising:
operating an LDPC (Low Density Parity Check) decoder circuitry for employing a plurality of configurations of a superimposed LDPC matrix for respectively decoding a plurality of LDPC coded signals, the superimposed LDPC matrix corresponding to LDPC codes of an in-place LDPC code set, wherein:
each of the LDPC codes having a respective code rate; and
each of the LDPC codes having a respective LDPC matrix;
based on a selected LDPC code of the in-place LDPC code set, selectively enabling or disabling sub-matrices of the superimposed LDPC matrix for within each of the plurality of configurations;
when the superimposed LDPC matrix being within a first of the plurality of configurations, operating the LDPC decoder circuitry for decoding a first of the plurality of LDPC coded signals thereby generating a first plurality of information bit estimates; and
when the superimposed LDPC matrix being within a second of the plurality of configurations, operating the LDPC decoder circuitry for decoding a second of the plurality of LDPC coded signals thereby generating a second plurality of information bit estimates.
16. The method of claim 15 , wherein:
a first LDPC code of the in-place LDPC code set corresponding to a first code rate and a first LDPC matrix; and
a second LDPC code of the in-place LDPC code set corresponding to a second code rate, being higher than the first code rate, and corresponding to a second LDPC matrix, having fewer rows than the first LDPC matrix.
17. The method of claim 15 , wherein:
the superimposed LDPC matrix being partitioned into a systematic matrix portion and a parity matrix portion; and
the parity matrix portion having a lower triangular form.
18. The method of claim 15 , further comprising:
switching between the first of the plurality of configurations and the second of the plurality of configurations in accordance with a predetermined sequence.
19. The method of claim 15 , further comprising:
switching between the first of the plurality of configurations and the second of the plurality of configurations based on a change in at least one operating condition of the communication device or of a communication system in which the communication device being implemented.
20. The method of claim 15 , wherein:
the communication device being operative within at least one of a satellite communication system, a wireless communication system, a wired communication system, and a fiber-optic communication system.