Stopping criteria for turbo decoder
AssigneeApple Inc.
InventorsAwais M. Hussain, Tarik Tabet, Moustafa M. Elsayed
Life of this patent
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Abstract
This disclosure relates to providing negative stopping criteria for turbo decoding for a wireless device. A device may wirelessly receive turbo coded data. Turbo decoding may be performed on the turbo coded data. Performing turbo decoding may use one or more negative stopping criteria for early termination of the turbo decoding for each code block of the turbo coded data. The negative stopping criteria may be selected to terminate the turbo decoding of a code block early under poor wireless medium conditions. Turbo decoding of a code block may be terminated early if the one or more negative stopping criteria for the code block are met.
Claims20
A wireless device, comprising:
- a radio;
- a processing element coupled to the radio;
- wherein the radio and the processing element are configured to:
- wirelessly receive turbo coded data;
- perform turbo decoding on the turbo coded data,
- wherein performing turbo decoding uses one or more negative stopping criteria for early termination of unsuccessful turbo decoding for each code block of the turbo coded data, wherein the one or more negative stopping criteria are selected to terminate the unsuccessful turbo decoding of a code block early under poor wireless medium conditions, wherein the one or more negative stopping criteria are based at least in part on computed a priori likelihood ratios of information bits of the turbo coded data;
- and
- terminate the unsuccessful turbo decoding of a code block early if the one or more negative stopping criteria for the code block are met.
An apparatus, comprising a processing element configured to cause a wireless device to:
- wirelessly receive a code block of turbo coded data;
- performing turbo decoding of the code block of turbo coded data for up to a predetermined maximum duration;
- determine whether any of one or more positive stopping criteria or one or more negative stopping criteria for the turbo decoding have been met prior to the predetermined maximum duration,
- wherein the turbo decoding of the code block of turbo coded data is stopped upon meeting a positive stopping criterion, a negative stopping criterion, or the predetermined maximum duration,
- wherein the one or more positive stopping criteria, the one or more negative stopping criteria, and the predetermined maximum duration are configured to cause a duration of the turbo decoding of the code block to vary in a manner correlated with wireless medium conditions when receiving the code block of turbo coded data, and
- in response to one or more negative stopping criteria being met, terminate turbo decoding without successfully decoding the turbo coded data.
A method, comprising:
- by a turbo decoding module of a wireless device:
- receiving a plurality of code blocks of turbo coded data;
- performing turbo decoding of each code block of the plurality of code blocks of turbo coded data, comprising performing up to a predetermined maximum number of turbo decoding iterations on each code block;
- and
- determining, for each code block, whether any positive or negative stopping criteria have been met,
- wherein turbo decoding of a respective code block of turbo coded data is stopped upon meeting a positive stopping criterion, a negative stopping criterion, or the predetermined maximum number of turbo decoding iterations,
- wherein the negative stopping criteria and the predetermined maximum number of turbo decoding iterations are configured to cause turbo decoding of a code block to have a shorter duration if the wireless device is experiencing signal to interference plus noise ratio (SINR) in a first range of SINR values than if the wireless device is experiencing SINR in a second range of SINR values, wherein the first range of SINR values is lower than the second range of SINR values, and
- in response to a negative stopping criteria being met, stop turbo decoding of the respective code block of turbo coded data without successfully decoding the respective code block of turbo coded data.
Dependencies are inferred from the claim text.