Punctured convolutional codes

A method of generating a puncturing pattern of a predetermined length for use with a 1/n convolutional code, for an integer n>1, for encoding data for transmission over a channel using a punctured convolutional code having a predetermined code rate, wherein the 1/n convolutional code uses a predetermined set of binary generator polynomials comprising a first generator polynomial and a second generator polynomial, wherein the second generator polynomial has more non-zero coefficients than the first generator polynomial, the method comprising selecting a puncturing pattern of a plurality of candidate puncturing patterns of the predetermined length by:

• for each candidate puncturing pattern of the plurality of candidate puncturing patterns, simulating transmission of data encoded using the 1/n convolutional code punctured in accordance with the respective candidate puncturing pattern over a noisy channel, and determining a respective transmission error rate for the simulated transmission using the candidate puncturing pattern;
• and
• comparing the determined transmission error rates for the plurality of candidate puncturing patterns to identify a candidate puncturing pattern that has a lowest transmission error rate of all the plurality of candidate puncturing patterns, wherein the plurality of candidate puncturing patterns includes only candidate puncturing patterns that puncture no more coded bits generated by the second generator polynomial than they puncture coded bits generated by the first generator polynomial.