Simple MAP acceleration using pre-decoding for punctured turbo code

A simple algorithm that accelerates maximum a posteriori (MAP) decoding of a punctured turbo code is proposed. A turbo code consists of a data bit stream and a plurality of parity bit streams, some of which possibly had components removed by puncturing. The proposed method performs pre-decoding and re-encoding to find omitted parity symbols of the received sequence. This protocol provides a turbo-coded system of between rate-1/2 and rate-1/3. Simulation results show that the proposed algorithm reduces the number of iterations, which is equivalent to the decoding delay, to 50% for approaching a bit error rate (BER) of approximately 3.38 times 10^-3 at 1.0 dB.