Generalized Polar Codes
AssigneeSocpra Sciences Et Genie S.E.C.
InventorsDavid Poulin, Andrew J. Ferris
Life of this patent
Estimating the term…
Abstract
A method for determining the n best positions of frozen bits in a channel decoder for a noisy communication channel. A decoding method and decoding processing unit for implementing the channel having frozen bits at the n worst positions. A method and system that iteratively, for each bit i from the n bits, determines a probability vector for the bit i by traversing a logical graph using contraction identities simplified to specific values, indexes the specific values from the contraction identities newly computed during the determination of the probability vector for subsequent reference during a following iteration based on corresponding contraction identities, fixes the bit i from the probability vector and moving to bit i+1 until all n bits are fixed.
Claims15
A method for determining the n best positions of frozen bits in a channel decoder for a noisy communication channel, the method comprising:
- selecting a polar code encoding scheme;
- obtaining a polar code decoder scheme corresponding to the polar code encoding scheme;
- determining a channel bandwidth defining a number of channel bits;
- determining a message length defining a number of message bits, the number of channel bits and the number of message bits defining a number of frozen bits n;
- notwithstanding the nature of the noisy communication channel, characterizing the communication channel with an erasure probability p;
- and
- computing the n worst positions considering the probability p.
A method for iteratively decoding a message of n bits to obtain a message of m<n bits, the message being received over a noisy communication channel exhibiting correlated noise characterized by a bad-state probability of erasure p1, a good-state of erasure p2, the probability of p2≤p1, wherein the channel provides a probability of transition between the good state and the bad state Pgb and between the good state and the bad state Pbg, the method comprising:
- iteratively, for each bit i from the n bits:
- determining a probability vector for the bit i by traversing a logical graph using contraction identities simplified to specific values;
- indexing the specific values from the contraction identities newly computed during the determination of the probability vector for subsequent reference during a following iteration based on corresponding contraction identities;
- fixing the bit i from the probability vector;
- and
- moving to bit i+1 until all n bits are fixed.
A system for iteratively decoding a message of n bits to obtain a message of m<n bits, the message being received over a noisy communication channel exhibiting correlated noise characterized by a bad-state probability p1, a good-state of erasure p2, the probability of p2≤p1, wherein the channel provides a probability of transition between the good state and the bad state Pgb and between the good state and the bad state Pbg, the system comprising:
- a processing module that iteratively, for each bit i from the n bits:
- determines a probability vector for the bit i by traversing a logical graph using contraction identities simplified to specific values;
- indexes the specific values from the contraction identities newly computed during the determination of the probability vector for subsequent reference during a following iteration based on corresponding contraction identities;
- fixes the bit i from the probability vector;
- and
- moves to bit i+1 until all n bits are fixed.
Dependencies are inferred from the claim text.