Dynamically scaled LLR for an LDPC decoder

A system for decoding an LDPC (low-density parity check) code word, comprising:

• a demodulation unit for generating a plurality of LLR (log likelihood ratio) terms;
• a scaling unit coupled to receive the plurality of LLR terms from the demodulation unit,
• wherein the scaling unit is configured to generate a scaling factor in accordance with at least one parameter descriptive of communication channel conditions of a receiver, and apply the scaling factor to each of the plurality of LLR terms to compute a corresponding plurality of scaled LLR terms, wherein the scaling factor is generated in accordance with a power spread value of a plurality of FFT (Fast Fourier Transform) bins;
• and
• an LDPC decoder unit coupled to receive the plurality of scaled LLR terms from the scaling unit, wherein the LDPC decoder unit is configured to execute an iterative layered belief propagation algorithm using the plurality of scaled LLR terms to decode the LDPC codeword.

A method for decoding an LDPC (low-density parity check) code word, comprising:

• demodulating an OFDM signal to generate a plurality of LLR (log likelihood ratio) terms;
• computing a parameter descriptive of communication channel conditions for a receiver;
• computing a scaling factor in accordance with the parameter, wherein the scaling factor is dynamically altered in accordance with changes to the parameter, and wherein the scaling factor is generated in accordance with a power spread value of a plurality of FFT Fast Fourier Transform) bins;
• computing a plurality of scaled LLR terms by using the scaling factor and the plurality of LLR terms;
• and
• executing an iterative layered belief propagation algorithm by using the plurality of scaled LLR terms to generate decoded information.