Encoding apparatus, decoding apparatus, and encoding and decoding system

摘要

An encoding apparatus derives a bit order based on a puncturing table that specifies different puncturing patterns for different transmission rates. The encoding apparatus then generates an error correcting code from an input information bit string and rearranges the error correcting code in the derived bit order. The error correcting code is punctured by taking a number of consecutive bits from the rearranged error correcting code. The number of bits taken varies depending on the transmission rate. The punctured error correcting code is output to a decoding apparatus, which realigns the code bits according to the transmission rate and the puncturing table, then uses the realigned error correcting code to correct errors in erroneous data. Rearrangement of the error correcting code makes the puncturing process more efficient by avoiding the need to decide whether to take or discard each bit individually.

主权项

1. An encoding apparatus for generating a punctured error correcting code at a selectable transmission rate from an input information bit string, comprising:
a bit-ordered encoder for generating an error correcting code from the input information bit string, deriving a bit order based on a puncturing table that specifies different puncturing patterns for different transmission rates, rearranging the error correcting code according to said bit order, and outputting the rearranged error correcting code; and a puncturing unit for receiving the rearranged error correcting code and information designating the transmission rate, generating the punctured error correcting code by taking bits from the rearranged error correcting code according to the designated transmission rate, and outputting the punctured error correcting code to a decoding apparatus, wherein the bit-ordered encoder further comprises
a bit order designator for deriving the bit order from the puncturing table; andan encoder for generating and rearranging the error correcting code, and wherein the bit order designator assigns index values to bit positions in the rearranged error correcting code and assigns bits that are taken at comparatively low transmission rates to bit positions with comparatively low index values, the encoder outputs the rearranged error correcting code in order of the assigned index values, and the puncturing unit takes the bits in consecutive order of their index values, starting from a bit position with a lowest index value.