US 8,413,031 B2 · Methods, apparatus, and systems for updating loglikelihood ratio information in an nT implementation of a Viterbi decoder

Abstract

Methods and circuits comprising a reliability measurement unit (RMU) for generating log-likelihood ratio (LLR) values corresponding to 1T for use in a soft output Viterbi algorithm (“SOVA”) decoder. The RMU operates with an nT clock signal. 1T signals generated by an add, compare, select circuit (ACS) of the SOVA generates 1T decision data and a path equivalency detector generates 1T path equivalency information for 1T SOVA decoding and applies the 1T data to the RMU operating with an nT clock frequency (1/n'th that of the 1T clock signal). The nT RMU receives a plurality of 1T inputs on each nT clock signal pulse and generates 1T LLR information for use by the SOVA decoder. Other components of the SOVA may also operate using the nT clock signal pulse or may operate using a 1T clock signal.

Claims11

Dependent claims

A method for generating 1T log-likelihood ratio (LLR) values from an nT reliability measurement unit (RMU) in a soft output Viterbi algorithm (SOVA) decoder where n is greater than 1, the method comprising:

responsive to each nT clock pulse, performing the steps of:
receiving multiple inputs in the RMU the multiple inputs corresponding to signals generated by 1T operation of the SOVA decoder;
generating LLR values in the nT RMU based on the received 1T multiple inputs;
and
outputting the LLR values as soft output information associated with the decision data output of the SOVA decoder.

2 more elements

A circuit usable in conjunction with a soft output Viterbi algorithm (SOVA) decoder, the SOVA decoder operable to generate 1T signals as inputs to the circuit, the circuit comprising:

an nT clock signal source adapted to generate an nT clock signal pulse at a frequency of 1/n of the data rate of the SOVA decode where n is greater than 1;
an nT reliability measurement unit (RMU) circuit coupled to receive the nT clock signal pulses, the RMU circuit adapted to receive 1T input signals from the SOVA decoder, the RMU circuit further adapted to output n log-likelihood ratio (LLR) values in response to each nT clock pulse signal, the LLR values based on the received 1T input signals, the n LLR values used by the SOVA decoder to determine a most likely output for a received symbol.

Dependencies are inferred from the claim text.

Methods, apparatus, and systems for updating loglikelihood ratio information in an nT implementation of a Viterbi decoder

Life of this patent

Methods, apparatus, and systems for updating loglikelihood ratio information in an nT implementation of a Viterbi decoder

Life of this patent

Abstract

Claims11