Toyota Jidosha Kabushiki Kaisha

Sharp Kabushiki Kaisha Corporation

National Institute of Information and Communications Technology, Incorporated

Osaka University

Masafumi Moriyama

Kenichi Takizawa

Fumihide Kojima

Atsushi Kurosawa

Yasuhiro Hamaguchi

Hiroshi Harada

Shimpei To

Seiichi Sampei

Hideo Nanba

Provided is a transmission control method for a plurality of 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 to the receiving station by repetition for a predetermined number of times at a predetermined cycle, wherein an information processing apparatus executes: acquiring information indicating a code word length for each of the plurality of transmitting stations to use for the repetition; and assigning, to each of the plurality of transmitting stations, transmitting power for ensuring a power difference which is required between transmitting stations, so that the shorter the code word length the higher the receiving power at the receiving station.

Transmission control method and information processing apparatus

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.

Wireless communication control method, receiving station, and non-transitory storage medium

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 φ(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 φ(g,n) to the transmission-side apparatus k. The phase rotation amount φ(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 φ(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.

Information processing apparatus, transmission-side apparatus and method

There is provided a transmission power control method for a terminal. In this method, when reception power is divided into at least two ranks at equal intervals, each of the at least two ranks has an allowable range having an identical size, a margin is set between a lower limit of the allowable range in an upper rank and an upper limit of the allowable range in a lower rank in the at least two ranks, and the allowable range is equal to or larger than the margin, the terminal adjusts transmission power of the first signal and the second signal by using a transmission power adjustment amount calculated by using reception power of the first signal and the second signal, a reception power difference between these signals, the at least two ranks, the allowable range, and the margin.

Transmission power control method, terminal, and wireless communication system

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.

Demodulating apparatus, base station and demodulating method

Each base station executes: a first process of acquiring a first signal from a first terminal from among signals simultaneously received from N terminals, and acquiring first data by demodulating and decoding the first signal; a second process of generating a second signal, which is a replica of a signal arriving from the first terminal based on the first data; a third process of acquiring signals by excluding the second signal from the signals simultaneously received from the N terminals; and sequentially repeating the first to third processes for the extracted signals, with one of N−1 terminals as a new first terminal. The base station shares the first data with other base stations through a backbone line, and, if the N terminals is larger than the M receive antennas in number, executes the second and third processes, using the first data received from another base station.

Base station, system and information processing method

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.

Reception-side apparatus and radio communication method

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 &#x3c6;(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 &#x3c6;(g,n) to the transmission-side apparatus k. The phase rotation amount &#x3c6;(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 &#x3c6;(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.

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.

Base station and communication method

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&#x3e;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.

An apparatus generating a packet of signals, a number of preamble signals of a preamble portion for each of a number of radio transmission units, and a number of data signals of a data portion, wherein a phase rotation in frequency domain is equal to a time shift in time domain is applied to each symbol of the number of preamble signals separately, the same phase rotation is applied to each symbol separately, the amount of the phase rotation is different for each preamble signal and each data signal, the amount of the phase rotation of one of the number of data signals and one of the number of preamble signals is both zero, and the amount of the phase rotation is equal between one of the preamble signals and one of the data signals for the same radio transmission unit.

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Koganei, Japan

Masafumi Moriyama