the invention is a recursive table - lookup decoding algorithm and also a method of decoding parallel - concatenated convolutional codes by utilizing the rltd algorithm so as to not require a mathematical / computational processor . the invention &# 39 ; s recursive table - lookup decoding algorithm approximates a maximum - a - posteriori decoder for convolutional codes . parallel - concatenated convolutional codes are error - correcting binary codes that are comprised of two or more constituent convolutional subcodes which share the same block of information bits , but in different interleaved time - index orderings . prior art of decoding devices for pccc &# 39 ; s require a mathematical / computational processor to perform computations such as multiplications and additions along with possibly other computations . the method of decoding pccc &# 39 ; s in this invention is summarized as taking quantized code symbols and iteratively performing the invention &# 39 ; s recursive table - lookup decoding algorithm for each constituent convolutional subcode of the pccc for a certain number of iterations whereby the decoded estimates for the information bits are obtained from a block of most - significant bits . the recursive table - lookup decoding algorithm recursively reads from a set of pre - stored lookup - tables . the invention includes a technique to create the binary address - words for accessing the lookup - tables . the invention &# 39 ; s algorithm can be made to closely approximate the well - known map / bcjr decoding algorithm by appropriately pre - storing the set of lookup - tables . moreover , the algorithm can be made to closely approximate modified versions of the bcjr algorithm that may be better at decoding specific pccc &# 39 ; s . the method of decoding in the invention can be implemented in software or hardware . a hardware implementation of the invention &# 39 ; s method of decoding would not require a mathematical / computational processor . the invention can be implemented with reasonably small sized lookup - tables for low - complexity pccc &# 39 ; s such as those with 2 - state convolutional encoders .