Satellite communication system utilizing low density parity check codes
An approach for reliably communicating over a satellite in support of a communication service including, for example, as direct broadcast satellite and data service, is disclosed. An input message is encoded, yielding a structured Low Density Parity Check (LDPC) coded message. The coded message is modulated according to a high order modulation scheme that has a signal constellation representing more than two symbols per signaling point—e.g., 8-PSK (Phase Shift Keying) and 16-QAM (Quadrature Amplitude Modulation). The system includes a transmitter configured to propagate the modulated signal over the satellite. The above approach is particularly applicable to bandwidth constrained communication systems requiring high data rates.
1. A method of encoding, the method comprising:
receiving an input message; and
generating an encoded message based on the input message according to a Low Density Parity Check (LDPC) coding scheme utilizing a parity check matrix configured to enable storage in memory for reading simultaneously from the memory adjacent relevant edge values corresponding to a group of bit nodes or a group of check nodes.
2. A method according to claim 1 , further comprising:
modulating a signal representing the generated message according to a high order modulation scheme.
3. A method according to claim 2 , further comprising:
broadcasting the signal over a satellite network.
4. A method according to claim 2 , wherein the signal is associated with one of a plurality of data rates, and the signal is decoded according to a decoding scheme that is independent from the data rates.
5. A method according to claim 1 , wherein the message includes a Reed-Solomon (RS) outer code, a Bose, Chaudhuri, and Hocquenghem (BCH) outer code, or a Hamming outer code.
6. A computer-readable medium bearing instructions for encoding, said instruction, being arranged, upon execution, to cause one or more processors to perform the method of claim 1 .
7. An apparatus comprising:
an encoder configured to generate a message based on a Low Density Parity Check (LDPC) coding scheme; and
a memory coupled to the encoder, wherein the LDPC coding scheme utilizing a parity check matrix configured to enable storage in memory for reading simultaneously from the memory adjacent relevant edge values corresponding to a group of bit nodes or a group of check nodes.
8. An apparatus according to claim 7 , further comprising:
a modulator coupled to the encoder and configured to modulate a signal representing the generated message according to a high order modulation scheme.
9. An apparatus according to claim 8 , wherein the signal is broadcast over a satellite network.
10. An apparatus according to claim 8 , wherein the signal is associated with one of a plurality of data rates, and the signal is decoded according to a decoding scheme that is independent from the data rates.
11. An apparatus according to claim 7 , wherein the message includes a Reed-Solomon (RS) outer code, a Bose, Chaudhuri, and Hocquenghem (BCH) outer code, or a Hamming outer code.
12. An apparatus comprising:
a decoder configured to receive a message that has been generated based on a Low Density Parity Check (LDPC) coding scheme; and
a memory coupled to the decoder, wherein the LDPC coding scheme utilizing a parity check matrix configured to enable storage in the memory for reading simultaneously from the memory adjacent relevant edge values corresponding to a group of bit nodes or a group of check nodes.
13. An apparatus according to claim 12 , further comprising:
a demodulator configured to demodulate a signal representing the message according to a high order modulation scheme.
14. An apparatus according to claim 13 , wherein the signal was broadcast over a satellite network.
15. An apparatus according to claim 13 , wherein the signal is associated with one of a plurality of data rates, and the signal is decoded according to a decoding scheme that is independent from the data rates.
16. An apparatus according to claim 12 , wherein the message includes a Reed-Solomon (RS) outer code, a Bose, Chaudhuri, and Hocquenghem (BCH) outer code, or a Hamming outer code.
17. A method comprising:
receiving a Low Density Parity Check (LDPC) coded message generated from a parity check matrix configured to enable storage in memory for reading simultaneously from the memory adjacent relevant edge values corresponding to a group of bit nodes or a group of check nodes; and
reading simultaneously from the memory the plurality of relevant edge values for decoding the LDPC coded message.