Abstract: A transmission system includes: an error correction encoding agent which converts an input data sequence into an encoded data sequence constituted of an error correction code and coded data; a data distribution agent which divides the encoded data sequence from the error correction encoding agent, in a predetermined processing unit and send them to a plurality of transmission routes; a data combining agent which combines signal sequences from the respective transmission routes and restores the encoded data sequence; an error correction decoding agent which applies error correction to and decodes the encoded data sequence from the data combining agent and outputs the input data sequence; and an agent for configuration in which a redundancy in the error correction encoding agent and a degree of splitting of the encoded data sequence in the data distribution agent are set.

Abstract: An optical transmission and reception system includes a transmitter and receiver. The transmitter differentially encodes control information to generate a differentially coded signal; uses the differentially coded signal to modulate a signal sequence in which electricity concentrates at a particular frequency; applies time-division multiplexing on the modulated signal sequence and a primary signal in one of two polarized wave components, and applies time-division multiplexing on the other polarized wave components and the signal sequence itself; and polarization-multiplexes the both of the time-division multiplexed polarized waves into an optical signal; and transmits the optical signal to the receiver.

Abstract: An increase in circuit scale is suppressed and a phase variation caused in a transmission path or the like is compensated for.

Abstract: The estimation of an amount of chromatic dispersion using a training signal sequence is possible. A transmission method includes: a training signal sequence generation step of generating, as training signal sequences, a plurality of signal sequences having power concentrated in a plurality of frequency bands, the power concentrated at different frequency bands; a training signal sequence selection step of selecting at least one training signal sequence from among the plurality of training signal sequences generated in the training signal sequence generation step, a signal multiplexing step of generating a signal sequence obtained by time-division multiplexing the training signal sequence selected in the training signal sequence selection step with a transmission data sequence, and an electrical-to-optical conversion step of transmitting the signal sequence generated in the signal multiplexing step as an optical signal.

Abstract: An optical receiving device receives an optical signal that has been modulated by means of phase modulation or quadrature amplitude modulation, converts the received optical signal into an electrical signal using coherent detection, and performs phase compensation on the converted received signal, and includes: a carrier phase estimation unit that estimates carrier phase errors in a received symbol string obtained from the received signal; a gain adjustment unit that performs gain adjustment on symbols input into the carrier phase adjustment unit; a phase cycle slip reduction unit that, by performing statistical processing on an output from the carrier phase estimation unit, detects general noise that causes a phase cycle slip, and reduces the phase cycle slip; and a phase compensation circuit that compensates carrier phase errors contained in the received signal using an output from the carrier phase estimation unit.

Abstract: The present invention provides a signal block sequence processing method. According to the method, signal block headers (Bch, Bdh) are deleted from each sequence of signal blocks (B) each composed of the signal block header indicating whether a signal block payload is a control block payload (Bc?) containing a control code is contained or a data block payload (Bd?) containing data is contained. The resultant signal blocks are formed into one group (G). Each control block payload in the group is provided with position determination information indicating the position of the control block payload in the group. The signal block payloads are rearranged in accordance with a signal block payload rearrangement rule. The rearranged signal block payloads are contained in a super-block payload (Sc), to which a super-block header (Shc) indicative of containment of control block payloads is added. The resultant super-block (S) is output.

Abstract: A transmission system comprising: an error correction encoding agent which converts an input data sequence into a coded data sequence constituted of an error correction code and coded data; a data distribution agent which divides encoded data sequence from the error correction encoding agent, in a predetermined processing unit and combines the divided data sequences with a plurality of transmission routes; a data combining agent which combines signal sequences from the respective transmission routes and decodes encoded data sequence; an error correction decoding agent which applies error correction to and decodes encoded data sequence from the data combining agent and outputs the input data sequence; and an agent for configuration in which a redundancy in the error correction encoding agent and a degree of splitting of encoded data sequence in the data distribution agent are set.

Abstract: An optical digital transmission system of the present invention newly defines one second negative stuff byte in an overhead area for accommodation of the client signals with multiplexing into the OTU frame, newly defines one third positive stuff byte in a corresponding tributary slot in a payload area for accommodation of client signals with multiplexing, newly defines stuff control bits that is used for decision of the use of the second negative stuff byte and the third positive stuff byte in three different places in the overhead area for client signal accommodation with multiplexing, performs control by using the newly defined stuff control bits when accommodation of the client signal with the third positive stuff byte or the second negative stuff byte is required, and performs stuff control without using the newly defined stuff control bits when accommodation of the client signal by the third positive stuff byte and the second negative stuff byte is not required.

Abstract: A digital transmission system includes at least a client device and a transmission device, and rate-adjusts the client signal transmitted from the client device to the transmission device before accommodating/multiplexing the signal in a frame. The transmission device includes a rate adjusting unit and a frame processing unit. The rate adjusting unit encapsulates the client signal by using a predetermined frame structure, inserts an idle pattern if necessary, and performs rate adjustment into the bit rate which can be contained in the frame. The frame processing unit accommodates/multiplexes the signal after the rate adjustment. The digital transmission system inserts a bit string of the client signal directly in a payload area of the digital frame, or accommodates and multiplexes it. Alternatively, a specific pattern is accommodated in the payload area, or accommodated and multiplexed after performing a reversible digital signal processing.

Abstract: According to the present invention, as shown in FIG. 5(a), when a signal for clock recovery ED is generated, which is formed by alternately generating enable periods EN having a ratio (N/M) of N clocks' client data to M clocks' line data and disable periods D1 to D4, a phase of the disable period D2 is advanced by a phase corresponding to the disable period (such as one clock period) during the enable period with reference to phase information added to the signal for clock recovery ED as shown in FIG. 5(c) when a stuff pulse in the line data is detected as indicated by the symbol m0 in FIG. 5(b), thereby generating the signal for clock recovery ED.

Abstract: An optical transmission system for performing frequency synchronization even with a client signal with low frequency accuracy, and for transmitting thereof by accommodating/multiplexing without causing a bit slip. A new overhead is added to the entire client signal, and the signal including the new overhead being stuffed is transmitted in conjunction with a plurality of stuffing bits as an optical signal wherein a data storing bit for a negative stuffing, a stuffing information notification bit, and a stuff bits inserting bit for a positive stuffing in the payload are defined in plurality as stuffing bits for adjusting clock frequencies of the client signal in this new overhead.

Abstract: An optical digital transmission system of the present invention newly defines one second negative stuff byte in an overhead area for accommodation of the client signals with multiplexing into the OTU frame, newly defines one third positive stuff byte in a corresponding tributary slot in a payload area for accommodation of client signals with multiplexing, newly defines stuff control bits that is used for decision of the use of the second negative stuff byte and the third positive stuff byte in three different places in the overhead area for client signal accommodation with multiplexing, performs control by using the newly defined stuff control bits when accommodation of the client signal with the third positive stuff byte or the second negative stuff byte is required, and performs stuff control without using the newly defined stuff control bits when accommodation of the client signal by the third positive stuff byte and the second negative stuff byte is not required.

Abstract: A multiplexing transmission system for adding a management overhead to a client signal, and transparently accommodating or multiplexing the client signal to transmit it is provided. The multiplexing transmission system: accommodates a plurality of client signals of different bit rates including a client signal of a bit rate that is not an integral multiple or an integral submultiple of a bit rate of other client signal, and performs rate adjustment for a part or the whole of the plurality of client signals such that the bit rate of each client signal becomes an integral multiple or integral submultiple of the bit rate of other client signal.

Abstract: A signal generating method and circuit for reducing jitters occurring in a recovered clock signal CK since even when multiple items of specific data are inserted in one cycle of generation period for an enable period, a deviation of an output cycle of the enable period can be eliminated. Accordingly, when a signal for clock recovery ED is generated, which is formed by alternately generating enable periods EN having a ratio (N/M) of N clocks' client data to M clocks' line data and disable periods D1 to D4, a phase of the disable period D2 is advanced by a phase corresponding to the disable period (such as one clock period) during the enable period with reference to phase information added to the signal for clock recovery ED when a stuff pulse in the line data is detected as indicated by the symbol m0, thereby generating the signal for clock recovery ED.

Abstract: The present invention provides a signal block sequence processing method. According to the method, signal block headers (Bch, Bdh) are deleted from each sequence of signal blocks (B) each composed of the signal block header indicating whether a signal block payload is a control block payload (Bc?) containing a control code is contained or a data block payload (Bd?) containing data is contained. The resultant signal blocks are formed into one group (G). Each control block payload in the group is provided with position determination information indicating the position of the control block payload in the group. The signal block payloads are rearranged in accordance with a signal block payload rearrangement rule. The rearranged signal block payloads are contained in a super-block payload (Sc), to which a super-block header (Shc) indicative of containment of control block payloads is added. The resultant super-block (S) is output.

Abstract: A multiplexing transmission system for adding a management overhead to a client signal, and transparently accommodating or multiplexing the client signal to transmit it is provided. The multiplexing transmission system: accommodates a plurality of client signals of different bit rates including a client signal of a bit rate that is not an integral multiple or an integral submultiple of a bit rate of other client signal, and performs rate adjustment for a part or the whole of the plurality of client signals such that the bit rate of each client signal becomes an integral multiple or integral submultiple of the bit rate of other client signal.

Abstract: The present invention proposes a method whereby during a specified/specifiable observation period (Ttotal) , the polarization states of optical transmission system and/or the optical signals transmitted by the optical transmission system are changed by applying a targeted intervention in at least one position of the transmission line, and at a second position which is interposed at least one place downstream from the first position of the optical transmission line, a specified/specifiable signal characteristic (BER) is qualitatively measured and checked for adherence to a specified/specifiable threshold condition (BERth) and the PMD-induced outage probability of the optical transmission system is calculated on the basis of the ratio between the length of that share of the time (Tout), during which the measured signal characteristic fails to meet the threshold condition (BERth), to the length of the observation period (Ttotal).

Abstract: A digital transmission system includes at least a client device and a transmission device, and rate-adjusts the client signal transmitted from the client device to the transmission device before accommodating/multiplexing the signal in a frame. The transmission device includes a rate adjusting unit and a frame processing unit. The rate adjusting unit encapsulates the client signal by using a predetermined frame structure, inserts an idle pattern if necessary, and performs rate adjustment into the bit rate which can be contained in the frame. The frame processing unit accommodates/multiplexes the signal after the rate adjustment. The digital transmission system inserts a bit string of the client signal directly in a payload area of the digital frame, or accommodates and multiplexes it. Alternatively, a specific pattern is accommodated in the payload area, or accommodated and multiplexed after performing a reversible digital signal processing.

Abstract: An optical transmission system for performing frequency synchronization even with a client signal with low frequency accuracy, and for transmitting thereof by accommodating/multiplexing without causing a bit slip. A new overhead is added to the entire client signal, and the signal including the new overhead being stuffed is transmitted in conjunction with a plurality of stuffing bits as an optical signal wherein a data storing bit for a negative stuffing, a stuffing information notification bit, and a stuff bits inserting bit for a positive stuffing in the payload are defined in plurality as stuffing bits for adjusting clock frequencies of the client signal in this new overhead.

Abstract: This digital transmission system is provided with a transmitting apparatus that transmits digital data signals and a receiving apparatus that receives the digital data signals transmitted over a transmission path, compares the signals with a predetermined threshold value, and performs decision reproduction. The receiving apparatus is formed by: decision circuits that receive the input of reception signals, discriminate between the respective reception signals using a plurality of threshold values, and output decision results; and a selection circuit that, based on the decision results output from the decision circuit, selects one decision result from one threshold value from among the decision results from each of the plurality of threshold values, and outputs the selected decision result. As a result, the receiving apparatus is able to individually select which decision result to use from which threshold value.