Abstract: A communication system including a parent station and a plurality of child stations, the parent station and the plurality of child stations being line-connected or loop-connected in a plurality of stages, and the parent station comprises a decision unit configured to decide, based on information representing states of the plurality of child stations, which one a first data relay method of transmitting data to a subsequent station in accordance with a clock reproduced from data received from a preceding station and a second data relay method of transmitting data to the subsequent station in accordance with a local clock generated in a local station should be employed by each of the plurality of child stations.

Abstract: A burst signal generator generates a burst signal that is a variable length portion whose length changes in accordance with fluctuations in data input at a predetermined period. An OFDM modulator generates an OFDM signal (including a guard interval portion and an effective symbol portion) that is a fixed length portion containing data corresponding to n (n is a positive integer) times or 1/n of the predetermined period. A frame includes the variable length portion and the fixed length portion. This makes a transmission signal actually have a frame period almost equal to the period of a signal synchronized with the clock of a player, including the fluctuations.

Abstract: A communication apparatus includes a detection unit configured to detect received powers of a plurality of radio signals received during a first predetermined time period from another apparatus, and a transmission unit configured to transmit by proxy identification information of the another apparatus using a detection result by the detection unit as at least one condition.

Abstract: A transmission apparatus for performing an orthogonal frequency division multiplexing (OFDM) transmission generates an OFDM symbol in which a modulation parameter used at a time of transmitting data is arranged in a subcarrier of a direct current component and transmits a transmission frame including the generated OFDM symbol. A receiving apparatus calculates an average value in an effective symbol period within the OFDM symbol included in the transmission frame received, extracts the modulation parameter arranged in the subcarrier of the direct current component based on the calculated average value, and performs OFDM demodulation processing using the extracted modulation parameter.

Abstract: A communication apparatus performs communication of data using assigned time slots within a frame. In a case where data cannot be transmitted in a transmission time slot that has been assigned in order to transmit data, a time slot later than this transmission time slot is reserved as a time slot used to transmit the data, this later time slot being reserved within the frame having the transmission time slot in which the data cannot be transmitted.

Abstract: Data is transmitted by using continuous frames each of which includes a variable-length part having a length that varies depending on an input period and a fixed-length part containing data of one input period. The transmitted continuous frames are received, a frame period is detected, and data is reproduced based on the detected frame period.

Abstract: Each of two communication apparatuses in a bi-directional communication system transmits to a partner communication apparatus as an OFDM signal at a predetermined carrier frequency an OFDM symbol having a guard interval length determined in advance and an effective symbol length determined in advance; receives the OFDM signal that has been transmitted by the partner communication apparatus; and carries out demodulation processing on the received OFDM signal in a period that does not include a symbol boundary of the received OFDM signal. A transmission timing of an OFDM signal in at least one of these communication apparatuses is controlled to a timing that precedes a symbol timing of the received OFDM signal by a predetermined time shorter than a total of transmission times of the bi-directional OFDM signal in the bi-directional communication.

Abstract: The parent station or a child station that transmits a pilot symbol is assigned to a pilot symbol transmission slot within a TDMA frame in a parent station or plurality of child stations for communicating using TDMA. The assigned parent station or child station transmits a pilot symbol using the pilot symbol transmission slot.

Abstract: Each of two communication apparatuses in a bi-directional communication system transmits to a partner communication apparatus as an OFDM signal at a predetermined carrier frequency an OFDM symbol having a guard interval length determined in advance and an effective symbol length determined in advance; receives the OFDM signal that has been transmitted by the partner communication apparatus; and carries out demodulation processing on the received OFDM signal in a period that does not include a symbol boundary of the received OFDM signal. A transmission timing of an OFDM signal in at least one of these communication apparatuses is controlled to a timing that precedes a symbol timing of the received OFDM signal by a predetermined time shorter than a total of transmission times of the bi-directional OFDM signal in the bi-directional communication.

Abstract: A transmission apparatus for performing an orthogonal frequency division multiplexing (OFDM) transmission generates an OFDM symbol in which a modulation parameter used at a time of transmitting data is arranged in a subcarrier of a direct current component and transmits a transmission frame including the generated OFDM symbol. A receiving apparatus calculates an average value in an effective symbol period within the OFDM symbol included in the transmission frame received, extracts the modulation parameter arranged in the subcarrier of the direct current component based on the calculated average value, and performs OFDM demodulation processing using the extracted modulation parameter.

Abstract: A burst signal generator generates a burst signal that is a variable length portion whose length changes in accordance with fluctuations in data input at a predetermined period. An OFDM modulator generates an OFDM signal (including a guard interval portion and an effective symbol portion) that is a fixed length portion containing data corresponding to n (n is a positive integer) times or 1/n of the predetermined period. A frame includes the variable length portion and the fixed length portion. This makes a transmission signal actually have a frame period almost equal to the period of a signal synchronized with the clock of a player, including the fluctuations.

Abstract: Data is transmitted by using continuous frames each of which includes a variable-length part having a length that varies depending on an input period and a fixed-length part containing data of one input period. The transmitted continuous frames are received, a frame period is detected, and data is reproduced based on the detected frame period.