Nec Corporation

Norifumi Kamiya

Eisaku Sasaki

Prakash Chaki

Kazuhiko Minematsu

Mamoru Sawahashi

Naoto Ishii

Masaaki Tanio

A communication system SYS includes a transmission apparatusand a reception apparatus. The transmission apparatus includes: a conversion unitfor converting a bit stream Z having a bit length b into a bit stream Y that has w−1 (w is an integer equal to or larger than 2) bitand that has a bit length n (n>b); a conversion unitfor converting the bit stream Y into a bit stream X having a bit length t (t<n); and a Neural Networkthat has a t input node and that outputs a value relating to a feature of a transmission signal Tx when the bit stream X is inputted thereto. The reception apparatus includes: a Neural Networkthat has a t output node and that outputs a numerical data stream U including t numerical data when a feature of the reception signal is inputted thereto; a conversion unitfor converting the numerical data stream U into a numerical data stream Y' including n numerical data; and a generation unitfor generating a bit stream Z′ having the bit length b by performing, on the numerical data stream U, an inverse conversion of a conversion processing performed by the conversion unit

Communication system, transmission apparatus, reception apparatus, matrix generation apparatus, communication method, transmission method, reception method, matrix generation method and recording medium

A parameter determination apparatus () includes: a first learning device () learning a weight between a [j&#x2212;1]-th layer (j is an integer that satisfies a condition that '2&#x2264;j&#x2264;the number of the layer') and a [j]-th layer to which an output of the [j&#x2212;1]-th layer is inputted among a plurality of layers of a neural network; a selecting device () selecting at least one valid path for each node included in the [j]-th layer from a plurality of connection paths that connect nodes in the [j&#x2212;1]-th layer and nodes in the [j]-th layer, respectively, on the basis of the weight learned by the first learning device; and a second learning device () learning at least one of the weight and a bias as the parameters relating to a network structure between the [j&#x2212;1]-th layer and the [j]-th layer on the basis of the sample signal, the label signal and the valid path.

Parameter determination apparatus, signal transmission apparatus, parameter determination method, signal transmission method and recording medium

A MAC tag list generation apparatus includes: a message input part; a group testing matrix generation part which generates a t&#xd7;m group testing matrix H that is a parameter(s) of combinatorial group testing with respect to the number s (s being a positive integer) of the MACs to be generated, a decodable linear group testing MAC application part which, with respect to the message M, using the group testing matrix H, a variable-length-input fixed-length-output pseudorandom function F; and a Tweakable block cipher G for which a row index of the group testing matrix H is a Tweak, generates a MAC tag list T=(T[1], . . . , T[t]); and a MAC tag list output part which outputs the MAC tag list.

MAC tag list generation apparatus, MAC tag list verification apparatus, method, and program

In order to achieve both of reduction of peak power and reduction of a transmission rate, an apparatus includes a reception processing unit configured to receive transmission signals from a transmission apparatus, the transmission apparatus performing precoding processing and clipping processing on the transmission signals and outputting a plurality of the transmission signals simultaneously in an identical frequency band; a signal separating unit configured to separate reception data sets from the transmission signals; and a transmission signal estimating unit configured to estimate a signal distortion component and a noise component due to the clipping processing and an interference component between the transmission signals, based on the reception data sets and gain information related to a channel for transmitting the transmission signals, and estimate transmission data sets by removing the signal distortion component, the noise component, and the interference component being estimated from the reception data sets.

Reception apparatus, signal processing method, and non-transitory computer readable recording medium

A MAC tag list generation apparatus, on reception of a nonce N unique value to each MAC generation process and a message M, generates a t&#xd7;m group test matrix H serving as combinatorial group testing parameters for s (a positive integer) which is the number of the MACs to be generated, generates a MAC tag list T=(T[1], . . . , T[t]) by generating a MAC value T[i] corresponding to the i-th test (i=1, . . . , t) using the group test matrix H, the nonce N, and pseudorandom functions F and G with variable length input and fixed length output for the message M, and outputs the MAC tag list.

MAC tag list generation apparatus, MAC tag list verification apparatus, aggregate MAC verification system and method

An apparatus performs a discrete Fourier transform process on M&#xd7;N received signal components included in a received signal, by a unit of N received signal components; and estimates an estimated signal containing M&#xd7;N estimated signal components, which are estimated values of M&#xd7;N transmission signal components, on the basis of the received signal on which the discrete Fourier transform process is performed. When the estimated signal xe is newly estimated, the apparatus performs an exclusion operation of excluding an estimated value xeof the M transmission signal components that constitute a k-th transmission signal group from the estimated signal xe newly estimated, and updates the estimated value xebased on an intermediate signal xtobtained by the exclusion operation and the received signal, thereby re-estimating the estimated signal xe.

Signal estimation apparatus, signal estimation method and program recording medium

A signal estimation apparatus classifies reception signal components included in a reception signal y and transmission signal components included in a transmission signal into a plurality of signal groups in accordance with a degree of a correlation between the reception signal component and the transmission signal component, on the basis of system information, sets, for each signal group, parameters &#x3b2;, &#x3c1;, &#x3c4; and &#x3b7; that specifies a detail of a signal estimation method to be either one of a learned value that is learnable by a learning operation and a fixed value that is independent from the learning operation, and estimates, for each signal group, an estimation signal xe that is an estimated value of the transmission signal from the reception signal by using the signal estimation method specified by the set parameter.

A communication apparatus for forward error correction and detection using polar codes comprising a polar encoder that encodes an input vector to output a codeword using a generator matrix of polar code wherein the input vector is a cyclic redundancy check (CRC) codeword of an information block; a memory that stores a frozen set including frozen bit indices and a non-frozen set including non-frozen bit indices sorted in order of error probabilities; and a controller that is configured to take as input the CRC codeword where CRC bits appended to the end of information block and interleave the CRC codeword using at least one of a first interleaver and second interleaver before feeding the CRC codeword to polar encoder such that the first interleaver places at least one CRC bit earlier than its original position in the CRC codeword and a second interleaver selects at least one bit from the CRC codeword whose corresponding index in a parity check matrix of the CRC code has the highest column weight and puts it in the non-frozen bit index with highest error probability.

Method and apparatus for construction of polar codes

A redundant bit generating device that generates redundant bits for error detection, that are added to a block of information bits, includes: a redundant bit calculation function that generates a predetermined number of redundant bits from the information bits according to a CRC polynomial; and a bit interleaving function that dispersedly arranges the predetermined number of redundant bits within the information bits using a permutation pattern determined based on the CRC polynomial.

Method and apparatus for generating redundant bits for error detection

A decoding apparatus includes a multi-input branch metric calculation unit configured to calculate, by using a branch label corresponding to a path extending toward a state S at a time point N in a trellis diagram and a plurality of reception signal sequences, a branch metric in the state S, a path metric calculation unit configured to calculate a path metric in the state S at the time point N, and a surviving path list memory configured to store path labels corresponding to L path metrics among a plurality of calculated path metrics. The path metric calculation unit generates a path label in the state S at the time point N by combining the branch label with a path label in each of the states at the time point N&#x2212;1 and the surviving path list memory outputs path labels corresponding to L path metrics.

Decoding apparatus, decoding method, and non-transitory computer readable medium

A communication device includes: an encoder that encodes an input vector to output a codeword using a generator matrix of polar code; a memory that stores a frozen set including frozen bit indices and a non-frozen set including non-frozen bit indices; and a controller that is configured to: a) select at least one check bit index from the frozen set in descending order of row weights of the generator matrix and in descending order of index reliabilities of the input vector; b) select at least one non-frozen bit index from the non-frozen set to compute at least one check bit from at least one bit of information bits at the at least one non-frozen bit index; and c) put the at least one check bit at the at least one check bit index.

Communication method and apparatus using polar codes

[Problem] Encoding and decoding techniques capable of speeding up an error-correction decoding process utilizing channel polarization are provided. [Solution] In an encoding device, the information bit sequence is input on division for each designated bit length; error-correction encoding is performed on an information block of the designated bit length to generate L M-bit codes, each M-bit code having a predetermined bit length M; the L M-bit codes are converted into M L-bit blocks each having a predetermined bit length of L; the M L-bit blocks are Polar-converted to M L-bit codes, each L-bit code having a bit length of L, through channel polarization processing; and division of the information bit sequence is determined based on channel polarization information.

Error-correction encoding method and device, and decoding method and device using channel polarization

A phase noise compensation apparatus is used for a demodulation apparatus for demodulating a transmission signal modulated by a modulation scheme that uses phase information for data identification. A phase detector detects a phase error of a reception pilot symbol sequence included in a reception symbol sequence. A first filter refers to the phase error detected in a time series manner and sequentially estimates first phase noise components. A second filter refers to the phase error detected in a reverse time series manner and sequentially estimates second phase noise components. The synthesis processing unit estimates a phase noise component of a reception symbol based on an estimated value of the first phase noise component, an estimated value of the second phase noise component, and the phase error. The phase rotator rotates a phase of the reception symbol based on the estimated phase noise component of the reception symbol.

Phase noise compensation apparatus, demodulation apparatus, communication apparatus, communication system, and phase noise compensation method

A modulation device includes a mapping circuit configured to map information bits to signal points on a plurality of concentric rings, when a signal space arrangement in which the number of signal points on all of the plurality of rings is the same is used as a basis, reduce the number of signal points on an innermost ring or a plurality of rings from inner to outer rings from among the plurality of rings, generate a new ring outside the signal space arrangement used as the basis, and arrange, on the generated ring, signal points which achieve the same frequency utilization efficiency as that of the signal space arrangement used as the basis.

Modulation method, decoding method, modulation device, and demodulation device

A LOS-MIMO demodulation apparatus comprises a plurality of receive antennas that receive data; a phase noise estimation part that calculates, from each signal received, first phase noise information and second phase noise information relating to phase noise occurring at transmit antennas and the receive antennas; a first correction part that corrects a phase of each signal received by the plurality of receive antennas according to the first phase noise information; a frequency domain equalization part that performs frequency domain equalization processing compensating for distortion due to interference from each signal received; a second correction part that corrects, according to the second phase noise information, a phase of each signal obtained by returning the signals, on which the frequency domain equalization processing has been performed, to the time domain by performing an inverse discrete Fourier transform; and a decoding processing part that performs decoding processing on the corrected data.

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Tokyo, Japan

Norifumi Kamiya