Abstract: A relay station includes a plurality of antennas and a controller. In non-regenerative relay of a first signal, the controller estimates an SINR of the first signal at a reception station after the relay on the basis of a transmit power of the first signal at a transmission station, first propagation characteristics between one or more first antennas set as reception antennas for the first signal and the transmission station, second propagation characteristics between one or more second antennas set as transmission antennas for the first signal after the relay and the reception station, a noise power and an interference power at the relay station, and a noise power at the reception station, and determines the first antennas and the second antennas in a combination that makes the SINR of the first signal at the reception station maximum respectively as the reception antennas and the transmission antennas.

Abstract: A communication system includes a first communication station, a second communication station, a relay station to relay a communication between the first communication station and the second communication station without changing a timeslot of the communication based on Time Division Multiplexing and a control apparatus. The control apparatus permits the relay station to perform a further communication in response to a communication request occurring in the relay station while relaying the communication, the further communication being directed to a third communication station when the communication to be relayed fulfill a first condition and when the further communication in response to the communication request fulfill a second condition.

Abstract: A floor mat arranged in a working machine includes a floor portion, a wall portion arranged on a circumferential portion of the floor portion, and an opening portion arranged on a part of a connecting portion of the wall portion, the connecting portion connecting to the floor portion. The floor mat includes a mat main body arranged on the floor portion, a covering portion configured to cover the opening portion, and an connecting portion configured to connect the covering portion flexibly to a circumferential portion of the mat main body.

Abstract: A reception-side apparatus includes: M receive antennas; and a processor configured to execute a first process of acquiring a first signal received from a first transmission-side apparatus from among signals simultaneously received from the N transmission-side apparatuses by receive diversity processing, and acquiring first data by demodulating and decoding the first signal. In the case of N>M, the processor acquires, for each of all patterns of a combination of a first signal, second signals from M?1 transmission-side apparatuses which are to be cancelled by receive diversity processing and third signals from N?M transmission-side apparatuses which are not to be cancelled by the receive diversity processing, a power ratio of power of the first signal relative to total power of the second and third signals based on a predetermined weight and a channel estimate of each signal, and selects a combination with the largest power ratio from among all the patterns.

Abstract: A wireless communication control method suppresses interference using an MMSE weight in an environment of wireless communication where the number of transmission stations transmitting a signal to a receiving station is larger than the number of reception antennas of the receiving station. The receiving station calculates power of an interference signal included in a signal received by the receiving station from the transmission stations the number of which is larger than the number of reception antennas, the interference signal corresponding to a part by which the number of transmission stations exceeds the number of reception antennas. The receiving station calculates the MMSE weight depending on the power of the interference signal, recalculates the power of the interference signal using the MMSE weight, and recalculates the MMSE weight depending on the recalculated power of the interference signal.

Abstract: A relay station comprises antennas, wireless devices corresponding to the antennas, and a controller to control an operation of the wireless devices. Each of the wireless devices includes a receiver to convert the first radio signal received by a corresponding antenna into a baseband signal, an FIR filter to assign a delay to the baseband signal; and a transmitter to convert a signal output from the FIR filter into a second radio signal transmitted from the corresponding antenna to the reception station. The controller sets a different delay amount in the FIR filter in each of the wireless devices so that the FIR filter assigns a delay, which is different from among the antennas, to the baseband signal input from the receiver in each of the wireless devices.

Abstract: A communication system includes a transmission station, a reception station, one or more relay stations configured to relay a first signal from the transmission station to the reception station without demodulating or decoding the first signal, and a controller. The controller is configured to acquire a first delay time and a first phase rotation amount to be provided to the first signal in relay by a first relay station so that one or more relay signals of the first signal arrive at the reception station at the same time and in the same phase after a first time length from a head of a slot in a radio frame and to cause the first relay station to provide the first delay time and the first phase rotation amount to the first signal.

Abstract: A first relay station capable of performing, together with a second relay station, a non-replay relay for a first radio signal transmitted from a transmitting station for a receiving station having one antenna includes an antenna, a radio and a controller. The radio includes a receiver that converts the first radio signal into a baseband signal, an FIR filter that adds a delay to the baseband signal, and a transmitter that converts the signal output from the FIR filter into a second radio signal transmitted from the antenna to the receiving station. The controller ensures that the second radio signals transmitted from the respective antennas of the first and second relay stations have different delays, and that the FIR filter The delay is set in the FIR filter.

Abstract: A communication system includes a first communication station, one or more relay stations to be communicable with the first communication station, a second communication station to be communicable with the first communication station via any of the relay stations or without via any of the relay stations and a controller. The controller determines the relay station serving as an interposition in communications between the first communication station and the second communication station to maximize the communication path capacity between the first communication station and the second communication station under a predetermined constraint condition, the communication path capacity being calculated based on radio wave propagation characteristics between the first communication station and each of the relay stations, the characteristics between each of the relay stations and the second communication station, and the characteristics between the first communication station and the second communication station.

Abstract: When signals are simultaneously received from K transmission-side apparatuses by a receiving antenna, and repetition is performed by the K transmission-side apparatuses, an information processing apparatus is configured to: in order to obtain a transmitted reference signal x(k,n) transmitted from a transmission-side apparatus k (k=1, . . . , K) by the n-th reference signal transmission in the repetition, acquire a phase rotation amount ?(g,n) given to a transmitted reference signal x(k) and assigned to a group g to which the transmission-side apparatus k belongs and transmit the phase rotation amount ?(g,n) to the transmission-side apparatus k. The phase rotation amount ?(g,n) is acquired so that received reference signals from transmission-side apparatuses not belonging to the group g are cancelled when a phase rotation amount opposite to the phase rotation amount ?(g,n) is given to a received reference signal r(n), and the first to N-th received reference signals in the repetition are added.

Abstract: In performing wireless communication between terminals to perform time difference measurement and propagation time measurement, first and second terminals that transmit a signal at least once in attempting space-time synchronization are included. The first terminal measures a reception phase of a locally transmitted signal, and a reception phase of a signal transmitted by the second terminal, adds a positive or negative phase to the measured reception phase, and makes a report to the second terminal. The second terminal measures a reception phase of a locally transmitted signal, and a reception phase of a signal transmitted by the first terminal, and makes a report to the first terminal. The first and second terminals obtain a time difference or propagation time according to a reception phase measured by a local device and reported from a counterpart, and obtain additional information based on a phase reflected in the time difference or propagation time.

Abstract: When signals are simultaneously received from K transmission-side apparatuses by a receiving antenna, and repetition is performed by the K transmission-side apparatuses, an information processing apparatus is configured to: in order to obtain a transmitted reference signal x(k,n) transmitted from a transmission-side apparatus k (k=1, . . . , K) by the n-th reference signal transmission in the repetition, acquire a phase rotation amount ?(g,n) given to a transmitted reference signal x(k) and assigned to a group g to which the transmission-side apparatus k belongs and transmit the phase rotation amount ?(g,n) to the transmission-side apparatus k. The phase rotation amount ?(g,n) is acquired so that received reference signals from transmission-side apparatuses not belonging to the group g are cancelled when a phase rotation amount opposite to the phase rotation amount ?(g,n) is given to a received reference signal r(n), and the first to N-th received reference signals in the repetition are added.

Abstract: A base station grants communications of a plurality of wireless communication terminals with the base station without allocating wireless resources upon occurrence of requests for the communications. The base station receives radio signals incoming from the wireless communication terminals and having encoded data, executes a first process of obtaining, from the received radio signals, first signals with at least ones of amplitudes and phases being adjusted, the first signals being incoming from a first wireless communication terminal among the plural wireless communication terminals, a second process of generating replicas of the radio signals incoming from the first wireless communication terminal before at least ones of the amplitudes and the phases are adjusted, a third process of extracting signals given by removing the replicas of the incoming radio signals from the received radio signals, and a process of iterating the first through third processes successively.

Abstract: The demodulating apparatus includes circuits of receiving modulated radio signals coming from a plurality of transmission devices, first demodulating a first reception signal DPSK-modulated among the radio signals, modulating demodulation signals into modulation signals based on DPSK, estimating an amplitude and a phase of a propagation signal on a propagation path leading to the reception circuit from the transmission device on the basis of the radio signal and the modulation signal, first generating, based on the variables, a first simulated signal simulating the first reception signal from the modulation signal, extracting a signal obtained by cancelling the first simulated signal from the radio signals, and repeating processes of the first demodulating, the modulating, the estimating, the first generating and the extracting to such a limit as to enable the first demodulating.

Abstract: In performing wireless communication between terminals to perform time difference measurement and propagation time measurement, first and second terminals that transmit a signal at least once in attempting space-time synchronization are included. The first terminal measures a reception phase of a locally transmitted signal, and a reception phase of a signal transmitted by the second terminal, adds a positive or negative phase to the measured reception phase, and makes a report to the second terminal. The second terminal measures a reception phase of a locally transmitted signal, and a reception phase of a signal transmitted by the first terminal, and makes a report to the first terminal. The first and second terminals obtain a time difference or propagation time according to a reception phase measured by a local device and reported from a counterpart, and obtain additional information based on a phase reflected in the time difference or propagation time.

Abstract: The demodulating apparatus includes circuits of receiving modulated radio signals coming from a plurality of transmission devices, first demodulating a first reception signal DPSK-modulated among the radio signals, modulating demodulation signals into modulation signals based on DPSK, estimating an amplitude and a phase of a propagation signal on a propagation path leading to the reception circuit from the transmission device on the basis of the radio signal and the modulation signal, first generating, based on the variables, a first simulated signal simulating the first reception signal from the modulation signal, extracting a signal obtained by cancelling the first simulated signal from the radio signals, and repeating processes of the first demodulating, the modulating, the estimating, the first generating and the extracting to such a limit as to enable the first demodulating.

Abstract: A reception-side apparatus includes: M receive antennas; and a processor configured to execute a first process of acquiring a first signal received from a first transmission-side apparatus from among signals simultaneously received from the N transmission-side apparatuses by receive diversity processing, and acquiring first data by demodulating and decoding the first signal. In the case of N>M, the processor acquires, for each of all patterns of a combination of a first signal, second signals from M?1 transmission-side apparatuses which are to be cancelled by receive diversity processing and third signals from N?M transmission-side apparatuses which are not to be cancelled by the receive diversity processing, a power ratio of power of the first signal relative to total power of the second and third signals based on a predetermined weight and a channel estimate of each signal, and selects a combination with the largest power ratio from among all the patterns.

Abstract: A wireless communication control method suppresses interference using an MMSE weight in an environment of wireless communication where the number of transmission stations transmitting a signal to a receiving station is larger than the number of reception antennas of the receiving station. The receiving station calculates power of an interference signal included in a signal received by the receiving station from the transmission stations the number of which is larger than the number of reception antennas, the interference signal corresponding to a part by which the number of transmission stations exceeds the number of reception antennas. The receiving station calculates the MMSE weight depending on the power of the interference signal, recalculates the power of the interference signal using the MMSE weight, and recalculates the MMSE weight depending on the recalculated power of the interference signal.

Abstract: Provided is a transmission control method for transmitting stations which are connected to a wireless communication partner receiving station by non-orthogonal multiple access, and each of which is capable of transmitting a same signal successively to the receiving station by repetition for a predetermined number of times at a predetermined cycle which is common to the transmitting stations. In this method, an information processing apparatus calculates an initial value of transmitting power to be assigned to each of the transmitting stations, so that the better a reception quality at the receiving station the higher the initial value, and that a power difference required between transmitting stations can be ensured, and calculates a number of times of repetition of a first transmitting station, to which the maximum initial value of the transmitting power is assigned, out of transmitting stations, based on an index value of the reception quality.

Abstract: The communication system includes a base station, a plurality of terminals to be Non-Orthogonal Multiple Access-connected (NOMA-connected) to the base station. The plurality of terminals including a relay terminal to relay uplink communication data to the base station and a relayed terminal to transmit the uplink communication data to the base station via the relay terminal. The relay terminal transmits, to the base station, overlap data given by getting its own uplink communication data based on a communication request occurring in the relay terminal to overlap with the uplink communication data coming from the relayed terminal.