Stmicroelectronics S.a.

Stmicroelectronics (grenoble 2) Sas

Stmicroelectroncis Sa

Laurent Paumier

Pascal Urard

Vincent Heinrich

Yan Meroth

Martial Comminges

Etiene Lantreibecq

The present disclosure relates to a method for interleaving a stream of input data blocks, the method comprising steps of: subdividing a block into sub-blocks of fixed size in number of data rows and data columns, the sub-blocks being distributed in the block in rows of sub-blocks and in columns of sub-blocks, transferring the data contained in the block into a first memory, while respecting the order of the data in the input stream, transferring the data contained in the block by row of sub-blocks, into a second memory in which the data of each sub-block is accessible from the address of the sub-block, transferring the data of each sub-block by column of sub-blocks, from the second memory into a third memory, by putting back the data of each sub-block in data rows and columns, and transferring the data by data column from the third memory into an output stream.

Method and device for row and column interleaving of blocks of variable size

A barrel shifter receiving N symbols, arranged ndistinct groups of nsymbols, applying a circular shift to the N symbols. The barrel shifter comprises nfirst barrel shifters, each applying a first circular shift to one of the groups of nsymbols; a rearrangement module receiving the N symbols provided by the first barrel shifters and providing N symbols arranged, in a determined manner, in ndistinct groups of nsymbols; nsecond barrel shifters, each applying a second circular shift to one of the distinct groups of nsymbols; a control module providing, to each first barrel shifter, an identical signal bs_ctrlrepresenting the first shift, and providing, to each second barrel shifter, an identical signal bs_ctrlrepresenting the second shift; and a switching module switching at least two of the symbols of the N symbols.

Barrel shifter

A low density parity check decoder for performing LDPC decoding based on a layered algorithm applied to a parity check matrix, the decoder including a channel memory, a metrics memory, first and second operand supply paths each arranged to provide operands based on channel values and metrics values; a processor block including a plurality processing units in parallel and arranged to receive operands from the first supply path and to determine updated metric values, a buffer arranged to store at least one of the operands from the first supply path; and an adder coupled to an output of the processor block and arranged to generate updated channel values by adding the updated metrics values to operands from a selected one of the buffer and the second supply path.

LDPC decoder and method for LDPC decoding based on layered algorithm applied to parity check matrix

An electronic device includes N inputs to receive R input data, R being able to take values from 1 to N, and N outputs. A configurable shift circuit is coupled between the N inputs and N outputs and has a cascade of shift stages, each shift stage comprising at least N controllable multiplexers. Each multiplexer includes first and second elementary inputs respectively coupled to a first input and a second input taken from among the N inputs so as to, on command, not shift a data item present on the first elementary input and shift a data item present on the second elementary input by an elementary shift value dependent on a rank of the shift stage, a direction of the shift being identical for each multiplexer. Control circuitry controls the multiplexers to deliver the R input data on R outputs.

Electronic multimode data shift device, in particular for coding/decoding with an LDPC code

The metrics matrix may include at least one particular layer including at least one particular column having several metrics cues, respectively, situated in different rows. For the particular layer, the updating of the channel cue is associated with the particular column involving at each iteration one updated metric cue selected from all the metrics cues of the particular column. The row of the selected metric cues may change at each iteration.

Method and device for layered decoding of a succession of blocks encoded with an LDPC code

An input memory of an LDPC decoder is loaded with data corresponding to an LDPC frame to be decoded and including N LLRs, of which K are information LLRs and N&#x2212;K are parity LLRs. At least one stream is formed of binary words of a first type, each corresponding to multiple information LLRS, with the aid of a serial/parallel conversion module, and at least one stream is formed of binary words of a second type, each corresponding to multiple parity LLRs, with the aid of a row/column interlacing device comprising a two-dimensional first-in first-out ring buffer. The first memory accesses are made in page mode in order to write the binary words of the first type to a first zone of the input memory, and the second memory accesses are made in page mode in order to write the binary words of the second type to a second zone.

Loading the input memory of an LDPC decoder with data for decoding

An image adapter transforms an input image into an output image by successively processing tiles and by changing numbers of columns and of rows of image points. The image adapter includes queue memories connected in series so as to receive values associated with the points of a tile of the input image. A module for calculating a weighted average possesses inputs connected respectively to an output of one of the memories. The module produces values sampled in a direction parallel to the columns and corresponding to the values associated with points of the input image. A sampling rate converter, connected to the output of the module, produces values associated with the points of the output image according to a sampling rate determined for a direction parallel to the rows.

Image adapter with tilewise image processing, and method using such an adapter

A method for the iterative decoding of a block of bits having a number N of bits to be decoded where N is a whole number greater than or equal to two, using an iterative decoding algorithm, comprises the generation of a current block of N intermediate decision bits by executing an iteration of the decoding algorithm, followed by the verification of a stability criterion for the current block by comparison of the current block with a given block of N reference bits. If the stability criterion is satisfied, the iterations of the iterative decoding algorithm are stopped and the current block of intermediate decision bits is delivered as a block of hard decision bits. Otherwise another iteration of the decoding algorithm is executed.

Iterative decoding of a frame of data encoded using a block coding algorithm

A concatenated channel decoding method wherein the bits of a set of N1 bits decoded using a first iterative block decoding algorithm and intended to be decoded using a second block decoding algorithm, are sent in parallel in at least one subset of P bits to a buffer for temporary storage. The decoding method comprises receiving in parallel at least one subset of Q bits belonging to the set of N1 bits sent to the buffer, detecting errors with the help of the second decoding algorithm, based on the bits decoded using the first decoding algorithm, and correcting the bits stored in the buffer as a function of possible errors detected. Detecting errors and/or the correcting the stored bits comprise a parallel processing of the bits of each subset of Q bits received.

Decoding with a concatenated error correcting code

A system implemented for example in the form of an SoC comprises a first demodulator for generating a first data stream to be decoded, and a second demodulator for generating a second data stream to be decoded, and a block decoder. The block decoder comprises an input memory for storing blocks of data from the first data stream and blocks of data from the second data stream, and a block decoding unit for processing, from the input memory, the blocks of data from the first and second data streams.

Decoding of multiple data streams encoded using a block coding algorithm

An LDPC decoder has a determined number of processing units operating in parallel. Storage circuitry contains first words having a juxtaposition of a first type of message. The storage circuitry also contains second words having a juxtaposition of a second type of message. A message provision unit provides each processing unit with the messages. A message write unit may write words into the storage circuitry in a way that depends on the contents of the words. The message provision unit may provide data in a way that depends on the contents of the words.

LDPC decoder

A device for storing blocks of bits intended to be decoded according to a block decoding algorithm. The blocks are likely to belong to a given category out of a first category and a second category. The first category corresponds to a first given block size, and the second category corresponds to at least one second given block size less than said first block size. The storage device comprises three storage elements having a size suitable for storing one block of the first category each, and at least two of which are structured to store either one block of the first category, or one block of the second category or a number of blocks of the second category simultaneously.

Block processing in a block decoding device

An LDPC decoder having a determined number of processing units operating in parallel, storage circuitry capable of containing first words containing a juxtaposition of messages of a first type, and second words containing a juxtaposition of messages of a second type, a message provision unit capable of providing each processing unit with a message of the first type or a message of the second type, and a message write unit capable of writing, into the storage circuitry, first words or second words. The message provision unit is capable of providing a message at a position in a word which depends on the word or the message write unit is capable of writing each message at a position in the word which depends on the word.

An interleaver includes two random access memories for storing data and an addressing device () linked to respective address inputs of the two memories. The addressing device is designed to transmit, at each instant of a clock, a cue for read access to one of the two memories and a cue for write access to the other of the two memories, so that, at each instant, a data item is written to or read from each memory.

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Grenoble, France

Laurent Paumier