Abstract: A wireless communication system includes a control device and at least one communication device. The control device includes a scheduler configured to generate control information for a process of a physical layer in wireless communication between the communication device and a terminal, an encoding unit configured to generate encoded data by performing encoding on data to be transmitted to the terminal on the basis of the control information, and a transmission unit configured to transmit the control information to the communication device when the control information is generated and transmits the encoded data to the communication device when the encoded data is generated.

Abstract: An optical communication system includes a signal processing apparatus and a wireless apparatus between which functions of a base station are divided, wherein a periodic symbol sequence including a cyclic prefix appended to a signal of a predetermined size to which an IFFT (Inverse Fast Fourier Transform) has been applied is transmitted between the signal processing apparatus and the wireless apparatus by means of digital RoF (Radio over Fiber) transmission, the signal processing apparatus and the wireless apparatus each include a transmission unit and a reception unit, the transmission unit includes: a compression size determination unit that acquires symbol information relating to a starting position of the symbol sequence and lengths of symbols constituting the symbol sequence, and that determines, based on the acquired symbol information, a compression size for each of symbols that are to be compressed; and a compression unit that compresses the symbol sequence in units of determined compression sizes, an

Abstract: A wireless communication system includes an RF reception unit configured to receive a radio signal from a terminal; a channel estimation unit configured to estimate channel information of a wireless transmission path with respect to the terminal; a demodulation unit configured to perform soft decision demodulation on the radio signal; a quantization unit configured to quantize a log likelihood ratio obtained through soft decision demodulation in the demodulation unit, on the basis of a statistical distribution determined using an average value of the log likelihood ratio determined in accordance with a modulation scheme used in wireless communication with the terminal and a variance of a log likelihood ratio obtained on the basis of the channel information; and a decoding unit configured to perform a decoding process on the log likelihood ratio quantized by the quantization unit.

Abstract: A relay apparatus includes: an estimation unit selects a code book number corresponding to a reception SNR range based on an estimated reception SNR value; a soft demodulation unit that performs soft demodulation on a received first signal to detect a likelihood of the received first signal; a first memory unit that stores a first quantization code book showing, for each code book number, a relationship between a quantization parameter and a likelihood quantization bit value; a quantization unit that refers the first quantization code book to obtain a relationship between a quantization parameter and a likelihood quantization bit value that corresponds to the selected code book number, and adaptively quantizes the detected likelihood by using the obtained relationship to obtain a likelihood quantization bit value; and a transmission unit that transmits, to the receiving apparatus, a second signal including the obtained likelihood quantization bit value and the selected code book number.

Abstract: A wireless communication system includes an RF reception unit configured to receive a radio signal from a terminal; a channel estimation unit configured to estimate channel information of a wireless transmission path with respect to the terminal on the basis of the radio signal received by the RF reception unit; a demodulation unit configured to perform soft decision demodulation on the radio signal on the basis of the channel information estimated by the channel estimation unit; a quantization unit configured to quantize a log likelihood ratio obtained through soft decision demodulation in the demodulation unit, on the basis of a statistical distribution determined using an average value of the log likelihood ratio determined in accordance with a modulation scheme used in wireless communication with the terminal and a variance of a log likelihood ratio obtained on the basis of the channel information; and a decoding unit configured to perform a decoding process on the log likelihood ratio quantized by the qu

Abstract: In a partial centralization system configuration, a wireless communication system of the present invention transmits a precoding matrix generated in a media access control (MAC) function or a matrix or vector obtained by dividing the precoding matrix between central unit equipment and distributed unit equipment in addition to data of modulated symbols necessary for a precoding matrix calculation and downlink control information (DCI) corresponding to the data.

Abstract: A wireless communication system includes a control device and at least one communication device. The control device includes a scheduler configured to generate control information for a process of a physical layer in wireless communication between the communication device and a terminal, an encoding unit configured to generate encoded data by performing encoding on data to be transmitted to the terminal on the basis of the control information, and a transmission unit configured to transmit the control information to the communication device when the control information is generated and transmits the encoded data to the communication device when the encoded data is generated.

Abstract: A station-side device performs transmission and reception of an optical signal to and from a subscriber-side device, and includes a communication control unit configured to perform optical signal communication using a plurality of wavelengths by wavelength division multiplexing and time division multiplexing; and a registration unit configured to set an acceptance period in at least one wavelength among the plurality of wavelengths, to perform a new registration of a subscriber-side device in response to a registration request of the subscriber-side device received within the acceptance period, and not to set the acceptance period in at least one other wavelength among the plurality of wavelengths.

Abstract: A wireless communication system includes distributed units communicating with a terminal device and a central unit connected to the distributed units and receiving and processing signals from the distributed units. The central unit includes a host function unit to pre-notify the distributed units if a received signal from the terminal device is a target of coordination between distributed units, hard/soft determination units configured to separate received signals from the distributed units into a hard decision value and a soft decision value based on presence or absence of coordination between the distributed units, transmit the hard decision value to the host function unit as is, and transmit the soft decision value to a signal combining unit, the signal combining unit combines soft decision values output from the hard/soft determination units and outputs a combined soft decision value, and a decoding unit performs decoding using the soft decision value output from the signal combining unit.

Abstract: An optical communication system includes a signal processing apparatus and a wireless apparatus between which functions of a base station are divided, wherein a periodic symbol sequence including a cyclic prefix appended to a signal of a predetermined size to which an IFFT (Inverse Fast Fourier Transform) has been applied is transmitted between the signal processing apparatus and the wireless apparatus by means of digital RoF (Radio over Fiber) transmission, the signal processing apparatus and the wireless apparatus each include a transmission unit and a reception unit, the transmission unit includes: a first separation unit that acquires symbol information relating to a starting position of the symbol sequence and lengths of symbols constituting the symbol sequence, and that equalizes the lengths of the symbols by separating a portion of the symbol sequence based on the acquired symbol information; and a compression unit that compresses symbols that are to be compressed from which the separated portion of th

Abstract: A relay apparatus includes: an estimation unit selects a code book number corresponding to a reception SNR range based on an estimated reception SNR value; a soft demodulation unit that performs soft demodulation on a received first signal to detect a likelihood of the received first signal; a first memory unit that stores a first quantization code book showing, for each code book number, a relationship between a quantization parameter and a likelihood quantization bit value; a quantization unit that refers the first quantization code book to obtain a relationship between a quantization parameter and a likelihood quantization bit value that corresponds to the selected code book number, and adaptively quantizes the detected likelihood by using the obtained relationship to obtain a likelihood quantization bit value; and a transmission unit that transmits, to the receiving apparatus, a second signal including the obtained likelihood quantization bit value and the selected code book number.

Abstract: A transmission system for relaying communication of communication systems includes a relay unit configured to relay uplink communication and downlink communication of a communication system that performs a time division duplex (TDD) mode through signals of different wavelengths, an information acquisition unit configured to acquire time division information indicating timings of the uplink communication and the downlink communication in the communication system that performs the TDD mode, a calculation unit configured to calculate a free period unused in relaying of communication of the communication system that performs the TDD mode on the basis of the time division information for each wavelength, and an instruction unit configured to instruct the relay unit to relay communication of another communication system different from the communication system that performs the TDD mode in the free period for each wavelength calculated by the calculation unit.

Abstract: An optical communication system includes a signal processing apparatus and a wireless apparatus between which functions of a base station are divided, wherein a periodic symbol sequence including a cyclic prefix appended to a signal of a predetermined size to which an IFFT (Inverse Fast Fourier Transform) has been applied is transmitted between the signal processing apparatus and the wireless apparatus by means of digital RoF (Radio over Fiber) transmission, the signal processing apparatus and the wireless apparatus each include a transmission unit and a reception unit, the transmission unit includes: a compression size determination unit that acquires symbol information relating to a starting position of the symbol sequence and lengths of symbols constituting the symbol sequence, and that determines, based on the acquired symbol information, a compression size for each of symbols that are to be compressed; and a compression unit that compresses the symbol sequence in units of determined compression sizes, an

Abstract: A transmission system for relaying communication of communication systems includes a relay unit configured to relay uplink communication and downlink communication of a communication system that performs a time division duplex (TDD) mode through signals of different wavelengths, an information acquisition unit configured to acquire time division information indicating timings of the uplink communication and the downlink communication in the communication system that performs the TDD mode, a calculation unit configured to calculate a free period unused in relaying of communication of the communication system that performs the TDD mode on the basis of the time division information for each wavelength, and an instruction unit configured to instruct the relay unit to relay communication of another communication system different from the communication system that performs the TDD mode in the free period for each wavelength calculated by the calculation unit.

Abstract: In a partial centralization system configuration, a wireless communication system of the present invention transmits a precoding matrix generated in a media access control (MAC) function or a matrix or vector obtained by dividing the precoding matrix between central unit equipment and distributed unit equipment in addition to data of modulated symbols necessary for a precoding matrix calculation and downlink control information (DCI) corresponding to the data.

Abstract: A station-side device performs transmission and reception of an optical signal to and from a subscriber-side device, and includes a communication control unit configured to perform optical signal communication using a plurality of wavelengths by wavelength division multiplexing and time division multiplexing; and a registration unit configured to set an acceptance period in at least one wavelength among the plurality of wavelengths, to perform a new registration of a subscriber-side device in response to a registration request of the subscriber-side device received within the acceptance period, and not to set the acceptance period in at least one other wavelength among the plurality of wavelengths.

Abstract: An optical communication system includes a signal processing apparatus and a wireless apparatus between which functions of a base station are divided, wherein a periodic symbol sequence including a cyclic prefix appended to a signal of a predetermined size to which an IFFT (Inverse Fast Fourier Transform) has been applied is transmitted between the signal processing apparatus and the wireless apparatus by means of digital RoF (Radio over Fiber) transmission, the signal processing apparatus and the wireless apparatus each include a transmission unit and a reception unit, the transmission unit includes: a first separation unit that acquires symbol information relating to a starting position of the symbol sequence and lengths of symbols constituting the symbol sequence, and that equalizes the lengths of the symbols by separating a portion of the symbol sequence based on the acquired symbol information; and a compression unit that compresses symbols that are to be compressed from which the separated portion of th

Abstract: A base station apparatus is provided with at least one remote unit apparatus each including at least one antenna, and a central unit apparatus connected to each remote unit apparatus via a transmission path. The antenna provided in the remote unit apparatus receives a transmission signal wirelessly transmitted from at least one wireless terminal each including at least one antenna.

Abstract: A wireless communication system includes distributed units communicating with a terminal device and a central unit connected to the distributed units and receiving and processing signals from the distributed units. The central unit includes a host function unit to pre-notify the distributed units if a received signal from the terminal device is a target of coordination between distributed units, hard/soft determination units configured to separate received signals from the distributed units into a hard decision value and a soft decision value based on presence or absence of coordination between the distributed units, transmit the hard decision value to the host function unit as is, and transmit the soft decision value to a signal combining unit, the signal combining unit combines soft decision values output from the hard/soft determination units and outputs a combined soft decision value, and a decoding unit performs decoding using the soft decision value output from the signal combining unit.

Abstract: Since a sampling frequency of RRU is always constant, A/D conversion may be performed with a sampling frequency higher than necessary with respect to a frequency band width of a radio signal. A sampling frequency change function, and the sampling frequency is reduced in a range where a aliasing component does not deteriorate signal quality of a desired signal component when the sampling frequency is decreased, based on radio band allocation information, or signal transmission between BBU and RRU is stopped in a no signal section, whereby a band required for digital RoF transmission between the BBU and the RRU is reduced.