Abstract: An information processing apparatus comprises a first heat generation circuit, a second heat generation circuit, a blocking assembly, and a processor. The blocking assembly performs a first operation of blocking air flowing from the first heat generation circuit toward the second heat generation circuit or a second operation of passing the air, and the processor is configure to instruct the blocking assembly to perform the first operation in a case where a temperature of the air is higher than a predetermined value, and instruct the blocking assembly to perform the second operation in a case where the temperature of the air is lower than the predetermined value.

Abstract: A transmitter according to the disclosure includes: an encoding unit that generates a code word by performing coding with a low-density parity-check code using a check matrix, the encoding unit being capable of switching the check matrix for use in generating the code word, between a first check matrix with a first code rate and a second check matrix with a second code rate smaller than the first code rate, the first check matrix containing a plurality of cyclic permutation matrices, the encoding unit generating the second check matrix by masking the cyclic permutation matrix at a predetermined position in the first check matrix and adding a row with a column weight equal to or less than a threshold; and a transmission unit that transmits the code word.

Abstract: Provided is an optical transmission/reception device including: an error correction encoding unit configured to encode a sequence to be transmitted with one type of LDPC code; and an error correction decoding unit configured to decode a received sequence encoded with the LDPC code. The error correction decoding unit performs decoding processing for the received sequence based on a check matrix of an LDPC convolutional code. The decoding processing is windowed decoding processing, which is performed by using a window extending over one or more check submatrices. A window size of the window and a decoding iteration count are configured to be variable, and the window size and the decoding iteration count are input from a control circuit connected to the error correction decoding unit.

Abstract: Provided is an optical transmission/reception device including an error correction decoding unit (36) for decoding a received sequence encoded with an LDPC code, in which the error correction decoding unit (36) is configured to perform decoding processing using a parity check matrix (70) of a spatially-coupled LDPC code, which includes a plurality of parity check sub-matrices (71) combined with each other, in which the decoding processing is windowed decoding processing that uses a window (80) over one or more parity check sub-matrices (71), and in which a window size of the window (80) and a decoding iteration count due to throughput and requested correction performance are variable and input from a control circuit (12) connected to the error correction decoding device (36).

Abstract: A transmitter according to the disclosure includes: an encoding unit that generates a code word by performing coding with a low-density parity-check code using a check matrix, the encoding unit being capable of switching the check matrix for use in generating the code word, between a first check matrix with a first code rate and a second check matrix with a second code rate smaller than the first code rate, the first check matrix containing a plurality of cyclic permutation matrices, the encoding unit generating the second check matrix by masking the cyclic permutation matrix at a predetermined position in the first check matrix and adding a row with a column weight equal to or less than a threshold; and a transmission unit that transmits the code word.

Abstract: Provided is an error correction device including an encoding circuit configured to encode a plurality of error correction code sequences, in which the encoding circuit includes a plurality of encoding circuits connected in parallel, and is configured to execute encoding processing for the plurality of error correction code sequences through use of all the plurality of encoding circuits by adjusting an output bus width and a frequency of an operation clock with respect to a difference in transmission rate for any payloads input in one or more systems.

Abstract: Provided is an optical transmission/reception device including an error correction decoding unit (36) for decoding a received sequence encoded with an LDPC code, in which the error correction decoding unit (36) is configured to perform decoding processing using a parity check matrix (70) of a spatially-coupled LDPC code, which includes a plurality of parity check sub-matrices (71) combined with each other, in which the decoding processing is windowed decoding processing that uses a window (80) over one or more parity check sub-matrices (71), and in which a window size of the window (80) and a decoding iteration count due to throughput and requested correction performance are variable and input from a control circuit (12) connected to the error correction decoding device (36).

Abstract: Provided is an optical transmission/reception device including: an error correction encoding unit configured to encode a sequence to be transmitted with one type of LDPC code; and an error correction decoding unit configured to decode a received sequence encoded with the LDPC code. The error correction decoding unit performs decoding processing for the received sequence based on a check matrix of an LDPC convolutional code. The decoding processing is windowed decoding processing, which is performed by using a window extending over one or more check submatrices. A window size of the window and a decoding iteration count are configured to be variable, and the window size and the decoding iteration count are input from a control circuit connected to the error correction decoding unit.

Abstract: Provided is an error correction device including an encoding circuit configured to encode a plurality of error correction code sequences, in which the encoding circuit includes a plurality of encoding circuits connected in parallel, and is configured to execute encoding processing for the plurality of error correction code sequences through use of all the plurality of encoding circuits by adjusting an output bus width and a frequency of an operation clock with respect to a difference in transmission rate for any payloads input in one or more systems.

Abstract: An optical transmission method wavelength-multiplexing and transmitting multiple channels including data. The data are composed of data areas independent between the channels and data areas non-independent between the channels. Data patterns of the data areas non-independent between the channels are variable. The data patterns of the data areas non-independent between the channels are set so that in time periods of the non-independent data areas on an optical transmission section, a time period during which polarization states of the multiple channels are correlated in the optical transmission section has a length such that an error rate is less than or equal to a threshold value, the error rate being determined from a temporal distribution of bit errors obtained from a result of error decision after demodulation in an optical receiver.

Abstract: A transmission device of a signal transmission system multiplexing and transmitting a plurality of 8B10B-coded information sequences, which includes: conversion units the number of which is identical to the number of the information sequences, to perform 8B10B-decoding of each of the information sequences, receive one of the information sequences after the decoding, scramble the received information sequence, and add a synchronous pattern indicating a head of a frame to the scrambled information sequence; and a multiplexing unit to multiplex the information sequence outputted from each of the conversion units.

Abstract: A transmission device of a signal transmission system multiplexing and transmitting a plurality of 8B10B-coded information sequences, which includes: conversion units the number of which is identical to the number of the information sequences, to perform 8B10B-decoding of each of the information sequences, receive one of the information sequences after the decoding, scramble the received information sequence, and add a synchronous pattern indicating a head of a frame to the scrambled information sequence; and a multiplexing unit to multiplex the information sequence outputted from each of the conversion units.

Abstract: A delay measuring device of a communication system that includes the delay measuring device sequentially transmitting and receiving frames having a known frame length, and a measurement object device serving as an object for measuring a round trip time by the delay measuring device, includes: an RTT measuring unit to measure a round trip time with respect to the measurement object device a number of times using information for delay measurement in the frame; an RTT change detection unit to detect a change of a value of the round trip time based on the values of the round trip time thus measured; and an RTT determination unit to determine a value of the round trip time to be adopted, from among the values of the round trip time, based on the change of a value of the round trip time.

Abstract: A likelihood generation apparatus for acquiring a likelihood of a 16QAM signal includes a first likelihood generation unit configured to generate a likelihood of each of two bits of a 16QAM signal point of the 16QAM signal from a relationship of each of an I-axis component and a Q-axis component with a likelihood when the 16QAM signal point is mapped on a constellation diagram, and a second likelihood generation unit configured to generate a likelihood of each of remaining two bits other than the two bits of the 16QAM signal point of the 16QAM signal based on a position of the 16QAM signal point in a lookup table, which is configured to input the I-axis component and the Q-axis component of the 16QAM signal point as arguments, and includes regions acquired by dividing the constellation diagram based on a possible value of each of the bits.

Abstract: A likelihood generation apparatus for acquiring a likelihood of a 16QAM signal includes a first likelihood generation unit configured to generate a likelihood of each of two bits of a 16QAM signal point of the 16QAM signal from a relationship of each of an I-axis component and a Q-axis component with a likelihood when the 16QAM signal point is mapped on a constellation diagram, and a second likelihood generation unit configured to generate a likelihood of each of remaining two bits other than the two bits of the 16QAM signal point of the 16QAM signal based on a position of the 16QAM signal point in a lookup table, which is configured to input the I-axis component and the Q-axis component of the 16QAM signal point as arguments, and includes regions acquired by dividing the constellation diagram based on a possible value of each of the bits.

Abstract: An optical transmission apparatus that accommodates client signals in a line signal, includes: an OPUn mapper unit that receives and maps the client signals; and a mapping control unit that determines the number of pieces of client data to be mapped to a payload portion and determines the timing to insert client data and information on the number of pieces of client data into the payload portion to control mapping performed in the OPUn mapper unit.

Abstract: A delay measuring device of a communication system that includes the delay measuring device sequentially transmitting and receiving frames having a known frame length, and a measurement object device serving as an object for measuring a round trip time by the delay measuring device, includes: an RTT measuring unit to measure a round trip time with respect to the measurement object device a number of times using information for delay measurement in the frame; an RTT change detection unit to detect a change of a value of the round trip time based on the values of the round trip time thus measured; and an RTT determination unit to determine a value of the round trip time to be adopted, from among the values of the round trip time, based on the change of a value of the round trip time.

Abstract: Provided is an optical communication cross-connection device for exchanging an OTN signal through optical communications, including: a plurality of OTN signal processing units (OTNsp units) for asynchronously conducting OTN signal processing; and a space switch connected between the plurality of OTNsp units, for conducting bidirectional signal exchange for the OTN signal, in which a first and a second OTNsp units that conduct signal transmission among the plurality of OTNsp units subject the OTN signal to skew processing on one side and deskew processing corresponding to the skew processing on another side between the first and second OTNsp units or between a communicating end-side one of the first and second OTNsp units and a communicating end-side OTNsp unit of an optical communication cross-connection device of a communication counterpart destination for the optical communication cross-connection device, and share a clock for the signal transmission therebetween.

Abstract: An optical transmission method wavelength-multiplexes and transmits multiple channels. Data transmitted on the wavelength-multiplexed channels are composed of data areas independent between the channels and data areas non-independent between the channels. Data patterns of the data areas non-independent between the channels are variable. This reduces the time period during which polarization states of the multiple channels are correlated, thereby reducing non-linear optical effects occurring between the channels and reducing deterioration in signal quality at a receiving end.

Abstract: An optical transmission device for transmitting and receiving a multilevel-modulated optical signal includes a plurality of transmission frame processors for generating transmission frame signals accommodating a plurality of client signals that are each subjected to error correction processing and scrambling/descrambling processing, and a digital modulator/demodulator for mapping the transmission frame signals that are input to and output from the plurality of transmission frame processors to a multilevel signal. The digital modulator/demodulator performs digital modulation/demodulation, in which the plurality of transmission frame processors each have a function of shifting a phase of a pattern between a plurality of transmission frames to be mapped to a multilevel signal and to be digitally modulated/demodulated.