Sets of rate-compatible universal turbo codes nearly optimized over various rates and interleaver sizes
A method and apparatus for Turbo encoding uses a set of rate-compatible Turbo Codes optimized at high code rates and derived from a universal constituent code. The Turbo Codes have rate-compatible puncturing patterns. The method comprises: encoding a signal at a first and second encoder using a best rate ½ constituent code universal with higher code rates, the first encoder and the second encoder each producing a respective plurality of parity bits for each information bit; puncturing the respective plurality of parity bits at each encoder with a higher rate best puncturing patterns; and puncturing the respective plurality of parity bits at each encoder with a lower rate best puncturing pattern. In a variation, the best rate ½ constituent code represents a concatenated of polynomials 1+D 2 +D 3 (octal 13) and 1+D+D 3 (octal 15), D a data bit. A Turbo Encoder is provided which has hardware to implement the method.
1. A method comprising:
encoding input bits using a turbo encoder having a transfer function G(D)=[1, (1+D+D 3 )/(1+D 2 +D 3 )];
puncturing parity bits produced by the turbo encoder to generate punctured encoded output bits with a desired coding rate; and
generating a radio signal based on the punctured encoded output bits.
2. The method of claim 1 , wherein puncturing parity bits produced by the turbo encoder to generate punctured encoded output bits with a desired coding rate comprises variably puncturing the parity bits produced by the turbo encoder to vary the coding rate.
3. The method of claim 2 , further comprising varying an interleaver depth used with the turbo encoder.
4. The method of claim 1 , further comprising varying an interleaver depth used with the turbo encoder.
5. The method of claim 1 , comprising using the turbo encoder over a range of input block sizes.
6. The method of claim 1 , wherein the turbo encoder is a rate 1/3 turbo encoder.
7. A system comprising:
an encoder circuit configured to generate encoded output bits from input bits using a turbo encoder having a transfer function G(D)=[1, (1+D+D 3 )/(1+D 2 +D 3 )] and configured to puncture parity bits produced by the turbo encoder to generate punctured encoded output bits with a desired coding rate; and
a radio transmission circuit configured to generate a radio signal based on the punctured encoded output bits.
8. The system of claim 7 , wherein the encoder circuit is configured to variably puncture the parity bits produced by the turbo encoder to vary the coding.
9. The system of claim 8 , wherein the encoder circuit is configured to vary an interleaver depth used with the turbo encoder.
10. The system of claim 7 , wherein the encoder circuit is configured to vary an interleaver depth used with the turbo encoder.
11. The system of claim 7 , further comprising a data segmentation circuit configured to vary an input block size for the turbo encoder.
12. The system of claim 7 , wherein the turbo encoder is a rate 1/3 turbo encoder.