Stopping criteria for iterative decoding
AssigneeBroadcom Corporation
InventorsBa-Zhong Shen, Kelly B. Cameron, Steven T. Jaffe
Life of this patent
Estimating the term…
Abstract
Method and apparatus for determining the stopping point of an iterative decoding process. In one embodiment the estimated values of an iteration of an iterative decoder are provided to a signature circuit. If the signature does not differ from the previous signature developed from a prior iteration, or the signature developed from an iteration prior to the previous iteration, the decoding stops. The variance may also be tested and compared to a threshold as a criteria to stop the iterative decoding.
Claims16
A method of generating a stopping criteria for an iterative decoder, the method comprising:
- performing an Nth iteration of decoding;
- forming a signature from extrinsic values of the Nth iteration;
- comparing the signature of the Nth iteration to a signature of the N−1st iteration;
- and
- stopping the process of iteration decoding if the signature of the N−1st iteration is equal to the signature of the Nth iteration.
A method of generating a stopping criteria for an iterative decoder, the method comprising:
- performing an Nth iteration of decoding;
- forming a signature from extrinsic values of the Nth iteration;
- comparing the signature of the Nth iteration to a signature of the N−2 iteration;
- and
- stopping the process of iteration decoding if the signature of the N−2 iteration is equal to the signature of the Nth iteration.
A method of generating a stopping criteria for an iterative decoder, the method comprising:
- determining the variance (VARk) of extrinsic information on a k′th iteration of the iterative decoder:
- halting the decoder if:
- VARk<T1, where T1 is a first threshold and Dk (Differential Variance)<T2 where T2 is a second threshold.
A method of determining a threshold T1 for a particular encoding, the method comprising:
- selecting a value for Eb/N0;
- creating a signal having the particular encoding;
- adding a noise vector to the signal to create a corrupted signal;
- iteratively decoding the corrupted signal until the iteration converges;
- and
- assigning a value less than VARk to T1.
A method of determining a threshold T2 for a particular encoding, the method comprising:
- selecting a value for Eb/N0;
- creating a signal having the particular encoding;
- adding a noise vector to the signal to create a corrupted signal;
- iteratively decoding the corrupted signal until the iteration converges;
- and
- assigning a value greater than Dk to T2.
An apparatus for generating a stopping criteria for an iterative decoder, the apparatus comprising:
- means for performing iterations of decoding;
- means for forming a signature from extrinsic values of an iteration of decoding;
- means for comparing the signature of an Nth iteration to a signature of an N−1st iteration;
- and
- means for stopping the process of iteration decoding if the signature of the N−1st iteration is equal to the signature of the Nth iteration.
An apparatus for generating a stopping criteria for an iterative decoder, the apparatus comprising:
- means for performing an iteration of decoding;
- means for forming a signature from extrinsic values of the iteration of decoding;
- means for comparing the signature of an Nth iteration of decoding to a signature of the N−2 iteration of decoding;
- and
- means for stopping the process of iteration decoding if the signature of the N−2 iteration is equal to the signature of the Nth iteration.
An apparatus for generating a stopping criteria for an iterative decoder, the apparatus comprising:
- means for determining the variance (VARk) of extrinsic information on an iteration of the iterative decoder;
- means for testing if VARk<T1, where T1 is a first threshold and Dk (Differential Variance)<T2 where T2 is a second threshold;
- and
- means for generating a stopping criteria if VARk<T1 and Dk<T2.
An apparatus for determining a threshold T1 for a particular encoding for a particular value for Eb/N0, the apparatus comprising:
- means for creating a signal having the particular encoding;
- means for adding a noise vector to the signal to create a corrupted signal;
- means for iteratively decoding the corrupted signal until the iteration converges;
- and
- means for assigning a value less than VARk to T1.
Dependencies are inferred from the claim text.