Abstract:
In a multicore type error correction processing system which can simultaneously cope with a plurality of error correction methods and a plurality of code lengths, an interconnect part 11 has a barrel shifter which extends across a plurality of error correction processing parts 12a-12c. An error correction process can be selectively performed by collectively using a group of the plurality of the error correction processing parts 12a-12c or by individually using each of individual error correction processing parts 12a-12c in response to interconnection configuration information. With this structure, the plurality of the error correction processing parts 12a-12c are collectively used if computation resources are insufficient and an idling error correction processing part is assigned to another error correction process if computation resources are excessive.
Abstract:
An error correction decoder for block serial pipelined layered decoding of block codes includes primary and mirror memories that are each capable of storing log-likelihood ratios (LLRs) for one or more iterations of an iterative decoding technique. The decoder also includes a plurality of elements capable of processing, for one or more iterations, one or more layers of a parity-check matrix. The elements include an iterative decoder element capable of calculating, for one or more iterations or layers, a LLR adjustment based upon the LLR for a previous iteration/layer, the LLR for the previous iteration/layer being read from the primary memory. The decoder further includes a summation element capable of reading the LLR for the previous iteration/layer from the mirror memory, and calculating the LLR for the iteration/layer based upon the LLR adjustment for the iteration/layer and the previous iteration/layer LLR for the previous iteration/layer.
Abstract:
A low density parity check decoder includes a decoding process divided into two or more processing stages arranged in series. At one time, each processing stage processes a different code block than each other processing stage in the series. The decoder is capable of simultaneously decoding as many code blocks as stages. A controller passes the code blocks between the processing stages at the proper time and in the proper sequence. The controller passes the code blocks through the series of stages in a time-division multiplexed fashion.
Abstract:
In a multicore type error correction processing system which can simultaneously cope with a plurality of error correction methods and a plurality of code lengths, an interconnect part 11 has a barrel shifter which extends across a plurality of error correction processing parts 12a-12c. An error correction process can be selectively performed by collectively using a group of the plurality of the error correction processing parts 12a-12c or by individually using each of individual error correction processing parts 12a-12c in response to interconnection configuration information. With this structure, the plurality of the error correction processing parts 12a-12c are collectively used if computation resources are insufficient and an idling error correction processing part is assigned to another error correction process if computation resources are excessive.
Abstract:
Techniques for implementing message passing decoders, e.g., LDPC decoders, are described. To facilitate hardware implementation messages are quantized to integer multiples of ? ln2. Messages are transformed between more compact variable and less compact constraint node message representation formats. The variable node message format allows variable node message operations to be performed through simple additions and subtractions while the constraint node representation allows constraint node message processing to be performed through simple additions and subtractions. Variable and constraint nodes are implemented using an accumulator module (1302), subtractor module (1304) and delay pipeline (1306). The accumulator module (1302) generates an accumulated message sum (1316). The accumulated message sum (1316) for a node is stored and then delayed input messages from the delay pipeline (1306) are subtracted there from to generate output messages (1321). The delay pipeline (1306) includes a variable delay element making it possible to sequentially perform processing operations corresponding to nodes of different degrees.
Abstract:
It is disclosed an optical coherent receiver comprising a number of decoding blocks configured to implement iterations of a FEC iterative message-passing decoding algorithm. The decoding blocks are distributed into two (or more) parallel chains of cascaded decoding blocks. The receiver also comprises an intermediate circuit interposed between the two parallel chains. The optical coherent receiver is switchable between (i) a first operating mode, in which the intermediate circuit is inactive and the two parallel chains separately implement the FEC message-passing decoding algorithm on respective client channels; and (ii) a second operating mode, in which the intermediate circuit is active and the two parallel chains jointly implement the FEC message-passing decoding algorithm on a same client channel, by cooperating through the intermediate circuit.
Abstract:
A decoder performs forward error correction based on quasi-cyclic regular column-partition low density parity check codes. A method for designing the parity check matrix reduces the number of short-cycles of the matrix to increase performance. An adaptive quantization post-processing technique further improves performance by eliminating error floors associated with the decoding. A parallel decoder architecture performs iterative decoding using a parallel pipelined architecture.