Error correcting decoder

A method of decoding a received binary data signal, where the data has been encoded as a product of codes prior to transmission, the method comprising:

• applying a multi-bit quantization to the received data signal to obtain input data comprising polarity information and confidence information for each bit in the received data signal;
• defining a small number of reliability categories based on degrees of similarity between component codes and candidate codewords;
• for component codes in turn, in a first processing phase:
• (a) attempting to select a candidate codeword based on the polarity and confidence information for the bits comprising the component code and assigning any selected candidate codeword to one of said reliability categories;
• (b) modifying the polarity and confidence information for the component code based on the assigned reliability category;
• and
• (c) repeating steps (a) and (b);
• and
• in a second processing phase:
• for sufficient component codes such that each bit in the received data is considered once:
• (d) attempting to select a candidate codeword based on the polarity and confidence information for the bits comprising the modified component code and assigning any selected candidate codeword to one of said reliability categories;
• and
• (e) modifying the polarity and confidence information for the modified component code based on the assigned reliability category to create the decoder output.

A decoder, for use in a system in which data has been encoded as a product of codes prior to transmission, and in which a multi-bit quantization has been applied to the received data signal to obtain input data comprising polarity information and confidence information for each bit in the received data signal, wherein the decoder is adapted to:

• for component codes in turn, in a first processing phase:
• (a) attempt to select a candidate codeword based on the polarity and confidence information for the bits comprising the component code;
• (b) according to the differences between the component code and the candidate codeword selected, modify the polarity and confidence information for the component code;
• and
• (c) repeat steps (a) and (b);
• and
• in a second processing phase:
• for sufficient component codes such that each bit in the received data is considered once:
• (d) attempt to select a candidate codeword based on the polarity and confidence information for the bits of the modified input data;
• and
• (e) according to the differences between the component code and the candidate codeword, modify the polarity and confidence information for the component code to create the decoder output.

A receiver, for use in a system in which data has been encoded as a product of codes prior to transmission, the receiver comprising:

• means for applying a multi-bit quantization to a received data signal to obtain input data comprising polarity information and confidence information for each bit in the received data signal, and
• a decoder, wherein the decoder is adapted to:
• for component codes in turn, in a first processing phase:
• (a) attempt to select a candidate codeword based on the polarity and confidence information for the bits comprising the component code;
• (b) according to the differences between the component code and the candidate codeword selected, modify the polarity and confidence information for the component code;
• and
• (c) repeat steps (a) and (b);
• and
• in a second processing phase:
• for sufficient component codes such that each bit in the received data is considered once:
• (d) attempt to select a candidate codeword based on the polarity and confidence information for the bits of the modified input data;
• and
• (e) according to the differences between the component code and the candidate codeword, modify the polarity and confidence information for the component code to create the decoder output.

A decoder, for use in a system in which data has been encoded as a product of codes prior to transmission, and in which a multi-bit quantization has been applied to the received data signal to obtain input data comprising polarity information and confidence information for each bit in the received data signal, wherein the decoder is adapted to:

• define a small number of reliability categories based on degrees of similarity between component codes and candidate codewords;
• for component codes in turn, in a first processing phase:
• (a) attempt to select a candidate codeword based on the polarity and confidence information for the bits comprising the component code and assign any selected candidate codeword to one of said reliability categories;
• (b) modify the polarity and confidence information for the component code based on the assigned reliability category;
• and
• (c) repeat steps (a) and (b);
• and
• in a second processing phase:
• for sufficient component codes such that each bit in the received data is considered once:
• (d) attempt to select a candidate codeword based on the polarity and confidence information for the bits comprising the modified component code and assign any selected candidate codeword to one of said reliability categories;
• and
• (e) modify the polarity and confidence information for the modified component code based on the assigned reliability category to create the decoder output.

A receiver, for use in a system in which data has been encoded as a product of codes prior to transmission, the receiver comprising:

• means for applying a multi-bit quantization to a received data signal to obtain input data comprising polarity information and confidence information for each bit in the received data signal, and
• a decoder, wherein the decoder is adapted to:
• define a small number of reliability categories based on degrees of similarity between component codes and candidate codewords;
• for component codes in turn, in a first processing phase:
• (a) attempt to select a candidate codeword based on the polarity and confidence information for the bits comprising the component code and assign any selected candidate codeword to one of said reliability categories;
• (b) modify the polarity and confidence information for the component code based on the assigned reliability category;
• and
• (c) repeat steps (a) and (b);
• and
• in a second processing phase:
• for sufficient component codes such that each bit in the received data is considered once:
• (d) attempt to select a candidate codeword based on the polarity and confidence information for the bits comprising the modified component code and assign any selected candidate codeword to one of said reliability categories;
• and
• (e) modify the polarity and confidence information for the modified component code based on the assigned reliability category to create the decoder output.