US 11,677,420 B1
Externalizing inter-symbol interference data in a data channel
Richard Galbraith, Rochester, MN (US); Jonas Goode, Lake Forest, CA (US); Iouri Oboukhov, Rochester, MN (US); and Niranjay Ravindran, Rochester, MN (US)
Assigned to Western Digital Technologies, Inc., San Jose, CA (US)
Filed by Western Digital Technologies, Inc., San Jose, CA (US)
Filed on Mar. 1, 2022, as Appl. No. 17/683,958.
Int. Cl. H03M 13/11 (2006.01); H03M 13/09 (2006.01)
CPC H03M 13/1125 (2013.01) [H03M 13/098 (2013.01); H03M 13/1114 (2013.01); H03M 13/1128 (2013.01)] 20 Claims
OG exemplary drawing
 
1. A read channel circuit, comprising:
a soft output detector configured to:
receive an input signal comprising digital bit samples from an analog data signal;
determine a first set of symbols with a first likelihood within a period of the input signal;
determine a second set of symbols with a second likelihood within the period of the input signal;
determine first inter-symbol interference data for adjacent symbols in the first set of symbols;
determine second inter-symbol interference data for adjacent symbols in the second set of symbols;
output soft information for the first set of symbols; and
output the first inter-symbol interference data and the second inter-symbol interference data;
an inter-symbol interference message passing model configured to:
receive the first inter-symbol interference data and the second inter-symbol interference data from the soft output detector; and
determine a change in the soft information for the first set of symbols based on:
the first inter-symbol interference data;
the second inter-symbol interference data; and
at least one error event; and
output the change in the soft information for the first set of symbols; and
an iterative decoder configured to use the change in the soft information for iterative decoding of the input signal to output a decoded data unit based on the input signal.