Abstract: A communication apparatus has an A/D converter which converts an analog signal which was received, into a digital signal, a converter which converts a reception signal so as to enable handling of phase information, a carrier detector which detects presence or absence of the reception signal, a synchronous circuit which extract synchronization timing from the reception signal, an equalizer which corrects the reception signal so as to cancel influence of a transmission path, a transmission path estimator which estimates a state of a power line transmission path, and a judging unit which judges the reception signal, which was amended by the equalizer, by use of a threshold value.

Abstract: The present invention relates to a transceiver and communication method involving a time division multiple transmission method, which performs data transmission among a plurality of transceivers. The transceiver includes a transmitter sending data, a receiver receiving data, a switch operable to switch among connecting the transmitter to a transmission line, connecting the receiver to the transmission line, or disconnecting both the transmitter and the receiver to the transmission line or connecting the transmission line to high impedance, and a controller operable to control the switch. The switch connects the transmitter or the receiver to the transmission line at a time that the transceiver has a relation to a communication designated by the time division multiplex transmission method.

Abstract: Channel estimation unit 16 includes CNR calculation unit 17, threshold setting unit 18, and modulation method determination unit 19. CNR calculation unit 17 calculates a CNR for each of a plurality of subcarriers from a received multicarrier communication signal. Threshold setting unit 18 takes statistics of a plurality of calculated CNRs, and, based on the statistics, sets CNR thresholds each assigned to one of a plurality of modulation methods. Modulation method determination unit 19 uses the set thresholds to determine a modulation method for each subcarrier, according to the calculated CNR of the subcarrier.

Abstract: A communication system includes a synchronizing signal generator that generates a synchronizing signal based on a timing of an alternating waveform in a power line, a data communicating circuit that performs the data communication, and a communication controller that controls to acquire a transmitting right utilizing a timing of the synchronizing signal and to control the communication circuit in accordance with whether or not the communication apparatus acquires the transmitting right.

Abstract: Power line communication apparatuses 100a, 100x each is equipped with a power line communication unit connected to a power line, for performing a power line communication; RFID tag 50a, 50x for storing thereinto communication setting information employed when a communication is carried out in the power line communication unit; and RFID tag reader 40a, 40x having an antenna, for reading out the information stored in the RFID tag 50a, 50x by employing a wireless communication. The power line communication apparatus 100a reads out the communication setting information of the power line communication apparatus 100x from the RFID tag 50x, and performs the power line communication with the power line communication apparatus 100x based upon the communication setting information.

Abstract: A communication apparatus 100 is equipped with, as plural communication sections capable of communicating with another communication apparatus over different transmission lines, a powerline communication section which performs a wired transmission using a powerline PL and a wireless communication section which performs a wireless transmission. The communication apparatus 100 causes at least one of the powerline communication section and the wireless communication section to perform a communication. If at least one of the powerline communication section and the wireless communication section is not to perform a communication, operation of that communication section is suspended.

Abstract: A communications device 100, which performs data communication, includes an AC cycle sensor 30 which is connected to a power line 106 supplied with an a.c. voltage and generates a synchronous signal SS at timing of an a.c. voltage waveform AC of the power line 106; a data communicator 10 for performing data communication; and a communications controller 20 which performs communication of a control signal including information showing at least one of a communications device and a communications standard and controls the data communicator 101. When the a.c. voltage supplied to the power line 106 is an N-phase and when the cycle of the a.c. voltage waveform is T, data communication to be performed in a communication period subsequent to the period is controlled on the basis of the control signal included in the period of T/2M on condition that M is a natural multiple of N.

Abstract: A transmitted digital signal from a digital signal processor is converted into an analog signal at an analog circuit, and then transmitted from transmission lines via a communication transformer. A communication apparatus has a plurality of communication modes that perform communication in different communication ranges. A controller in the digital signal processor changes an output level of the transmitted signal according to the communication modes. More specifically, the controller detects communication quality of the transmitted signal and lowers the output level of the transmitted signal within a range where the detected communication quality does not fall below predetermined quality.

Abstract: A communication apparatus has a electrical outlet that is electrically connected to a power connector so as to supply power externally; a connection detector that detects connection of an external plug to the electrical outlet; and a controller that uses a receiver and a transmitter so as to perform setting with a device connected to the electrical outlet, when external connection is detected at the electrical outlet.

Abstract: A communication apparatus repeatedly outputs a first multi-carrier signal SS during predetermined periods T1, T2, T3, . . . , and outputs a second multi-carrier signal RS whose phase vector is different from that of the first multi-carrier signal SS, at a predetermined timing based on the first multi-carrier signal SS. The communication apparatus further detects the second multi-carrier signal RS output from another communication apparatus, which uses a different communication method from the communication apparatus. Accordingly, both communication apparatuses can differentiate the first multi-carrier signal SS from the second multi-carrier signal RS without performing relatively cumbersome modulation and other processes.

Abstract: PLC modems and a PLC communication system that includes the PLC modems receive a multicast packet from a video server of a multicast group. When a MAC address table is set therein, the PLC modems and the PLC communication system convert the multicast packet into a unicast packet and transmit the converted packet to a power line. When no MAC address is set, the PLC modems and the PLC communication system transmit the multicast packet to the power line.

Abstract: A communication system includes a synchronizing signal generator that generates a synchronizing signal based on a timing of an alternating waveform in a power line, a data communicating circuit that performs the data communication, and a communication controller that controls to acquire a transmitting right utilizing a timing of the synchronizing signal and to control the communication circuit in accordance with whether or not the communication apparatus acquires the transmitting right.

Abstract: A PLC modem performs communication via transmission lines made of a pair of cables as an example of a wired transmission line. Data displaying an operation state of the PLC modem is transmitted to a light emitting part via a modulator, and is converted into a high-speed flash signal for output.

Abstract: In-home communication systems 110 and 130 and an access communication system 120 are caused to coexist by TDM in synchronization with a power cycle, and a communication system which needs to secure AV-QoS assigns transmission timing to a slave station in itself by synchronizing a beacon cycle with a cycle of a power line.

Abstract: A communication apparatus and a method are provided for easily enabling two communication systems having different communication schemes and using the same communication medium to coexist. An access coexistence signal for notifying an in-home communication system 110 and 130 of the presence of an access communication system 120, and an in-home coexistence signal for sharing frequency and time resources between a plurality of in-home communication systems 110 and 130, are used. Further, by transmitting the two coexistence signals asynchronously, a process of synchronizing the access communication system 120 and the in-home communication system 110 and 130 is no longer required.

Abstract: A wave detecting section of a receiver has a first wavelet transformer involving a plurality of wavelet filters orthogonal to each other for performing a wavelet transform on received waveform data, a Hilbert transformer for performing a Hilbert transform on the received waveform data, a second wavelet transformer having the same configuration as that of the first wavelet transformer for performing a wavelet transform on outputs from the Hilbert transformer, a code converter for inverting the codes of outputs in odd-numbered places among outputs from the second wavelet transformer, a level converter for correcting fluctuations of outputs from the code converter attributable to a ripple of the Hilbert transformer, and a complex data generator for generating complex data, by defining outputs of the first wavelet transformer as in-phase components of the complex information and outputs from the level converter as orthogonal components of the complex information.

Abstract: A digital transmission signal from a digital signal processing unit is converted to an analog signal in an analog circuit, and is transmitted from transmission lines via a communication transformer. The digital signal processing unit includes a time carrier detector that detects existence or non-existence of a carrier by using a temporal waveform of a reception signal, a frequency carrier detector that detects existence or non-existence of a carrier by using frequency characteristics of the reception signal, and an amplitude carrier detector that detects existence or non-existence of a carrier by using a frequency spectrum of the reception signal. Under the control of a controller, carrier detection is performed by switching between the time carrier detector, the frequency carrier detector and the amplitude carrier detector for activation.

Abstract: An in-home-system master station of an in-home communication system detects a frequency band (a channel number corresponding to a data communication subchannel) or a time slot used by each station of an access communication system, using a coexistence signal subchannel. Based on the detected information, the in-home-system master station determines a frequency band or a time slot to be used in the in-home communication system to which the in-home-system master station belongs, so as not to avoid overlapping the frequency or time slot used in the access communication system, and informs each in-home-system slave station of the determined frequency band or time slot.

Abstract: A wave detecting section of a receiver has a first wavelet transformer involving a plurality of wavelet filters orthogonal to each other for performing a wavelet transform on received waveform data, a Hilbert transformer for performing a Hilbert transform on the received waveform data, a second wavelet transformer having the same configuration as that of the first wavelet transformer for performing a wavelet transform on outputs from the Hilbert transformer, a code converter for inverting the codes of outputs in odd-numbered places among outputs from the second wavelet transformer, a level converter for correcting fluctuations of outputs from the code converter attributable to a ripple of the Hilbert transformer, and a complex data generator for generating complex data, by defining outputs of the first wavelet transformer as in-phase components of the complex information and outputs from the level converter as orthogonal components of the complex information.

Abstract: A digital transmission signal from a digital signal processing unit is converted to an analog signal in an analog circuit, and is transmitted from transmission lines via a communication transformer. The digital signal processing unit includes a time carrier detector that detects a carrier by using a time waveform of a reception signal and a frequency carrier detector that detects a carrier by using frequency characteristics of the reception signal. Under the control of a controller, carrier detection is performed by switching between the time carrier detector and the frequency carrier detector for operation.