The Royal Institution for the Advancement of Learning / Mcgill University

Pascal Giard

Gabi Sarkis

Warren Jeffrey Gross

Claude Thibeault

Camille Leroux

Methods and systems for encoding data are described herein. The method comprises inputting data to a first pipeline of a non-systematic polar encoder capable of encoding a polar code of length n, extracting, via at least one first multiplexer of size log n&#xd7;1, a first polar code of length n&#x3c;nat a first location along the first pipeline to generate a first encoded output, modifying the first encoded output to set frozen bits to a known value to obtain a modified first encoded output, inputting the modified first encoded output to a second pipeline of the non-systematic polar encoder, and extracting, via at least one second multiplexer of size log n&#xd7;1, a second polar code of length n&#x3c;nat a second location along the second pipeline to generate a second encoded output, the second encoded output corresponding to a systematically encoded polar code of length n.

Flexible polar encoders and decoders

There is described a multi-mode unrolled decoder. The decoder comprises a master code input configured to receive a polar encoded master code of length N carrying k information bits and N&#x2212;k frozen bits, decoding resources comprising processing elements and memory elements connected in an unrolled architecture and defining an operation path between the master code input and an output, for decoding a polar encoded code word, at least one constituent code input configured to receive a polar encoded constituent code of length N/p carrying j information bits and N/p&#x2212;j frozen bits, where p is a power of 2, and at least one input multiplexer provided in the operation path to selectively transmit N/p bits of one of the master code and the constituent code to a subset of the decoding resources.

Multi-mode unrolled polar decoders

Modern communication systems must cope with varying channel conditions and differing throughput constraints. Polar codes despite being the first error-correcting codes with an explicit construction to achieve the symmetric capacity of memoryless channels are not currently employed against other older coding protocols such as low-density parity check (LDPC) codes as their performance at short/moderate lengths has been inferior and their decoding algorithm is serial leading to low decoding throughput. Accordingly techniques to address these issues are identified and disclosed including decoders that decode constituent codes without recursion and/or recognize classes of constituent directly decodable codes thereby increasing the decoder throughput. Flexible encoders and decoders supporting polar codes of any length up to a design maximum allow adaptive polar code systems responsive to communication link characteristics, performance, etc. while maximizing throughput. Further, designers are provided flexibility in implementing either hardware or software implementations.

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Ecublens, Switzerland

Pascal Giard