Hierarchical trellis coded modulation
View Patent ↗A system and method for encoding information is disclosed. In one embodiment, information is encoded using a high protection code for the least significant bit and a low protection code for the next three most significant bits. The remaining bits are uncoded. The high protection code may be a turbo code and the low protection code may be a trellis coded modulation code. In this embodiment, the collection of bits is then mapped according to a diagonally shifted QAM constellation technique.
1. A system for encoding a quantity of electronic information, the system comprising:
a high protection code encoder configured to encode a first portion of the quantity of information to produce a first coded portion of information;
a low protection code encoder configured to encode a second portion of the quantity of information to produce a second coded portion of information such that the high protection code encoder and the low protection code encoder encode the first and second portions based on a 16-state 4D Wei code concatenated with a rate 1/2 parallel concatenated turbo code, wherein the first portion comprises a least significant bit, the second portion comprises a next three significant bits, and wherein any remaining bits are uncoded; and
a modulator configured to map the first coded portion of information, the second coded portion of information, and a third portion of the quantity of information to at least one symbol.
2. The system of claim 1 wherein the high protection code encoder does not limit the asymptotic performance of the system for encoding a quantity of electronic information.
3. The system of claim 1 wherein the high protection code encoder provides a free Euclidean distance d free,hpc and the low protection code encoder provides a free Euclidean distance d free,lpc such that d free,hpc >D N n+p d free,lpc , wherein D N n+p is a distance coefficient.
4. The system of claim 3 wherein
D
N
n
+
p
=
2
n
+
p
N
.
5. The system of claim 4 wherein the system is configured to produce a signal compromising a signal set selected from the group comprising one of: 1D lattice-type signal sets and 2D lattice-type signal sets.
6. The system of claim 3 wherein D 4 1 =D 4 2 =√{square root over (2)}, and D 4 3 =D 4 4 =2.
7. The system of claim 6 wherein the high protection encoder is configured to produce a signal comprising a 4D lattice-type signal set.
8. The system of claim 1 wherein the Wei code is consistent with ITU G.992.1 standard.
9. The system of claim 1 wherein the modulator is configured to use at least one diagonally shifted quadrature amplitude modulation constellation.
10. The system of claim 1 , wherein the high protection code encoder further comprises:
two rate 1/2 binary recursive systematic convolutional (RSC) encoders; and
a random interleaver,
wherein the random interleaver separates the two rate 1/2 binary RSC encoders with a size of 1,024 bits.
11. A system for encoding a quantity of electronic information, the system comprising:
means for encoding a first portion of the quantity of information according to a high protection code to produce a first coded portion of information;
means for encoding a second portion of the quantity of information according to a low protection code to produce a second coded portion of information such that the means for encoding a first portion and the means for encoding a second portion encode the first and second portions based on a 16-state 4D Wei code concatenated with a rate 1/2 parallel concatenated turbo code, wherein the first portion comprises a least significant bit portion, the second portion comprises a next least significant bit portion, and wherein any remaining bits are uncoded; and
means for mapping the first coded portion of information, the second coded portion of information, and a third portion of the quantity of information to at least one symbol.