Abstract: A channel characteristic obtaining method includes generating, by a first communication apparatus, a first reference signal and a first notification message, sending, by the first communication apparatus, the first reference signal and the first notification message to a second communication apparatus, and receiving, by the first communication apparatus, channel characteristic information of a first channel type from the second communication apparatus. The first channel type corresponds to first channel state information (CSI) determined by the second communication apparatus based on the first reference signal. The first notification message is useable to request the channel characteristic information of the first channel type. A channel characteristic of the first channel type is from a channel characteristic library. The channel characteristic library comprises channel characteristics of one or more channel types.

Abstract: Embodiments of this application provide a leaky coaxial cable and a communication system. The leaky cable includes: an inner conductor, an insulation layer, and an outer conductor, where the insulation layer is configured to separate the inner conductor from the outer conductor; and the outer conductor includes M perforated segments and N non-perforated segments, the M perforated segments and the N non-perforated segments are alternately arranged, at least one of the M perforated segments includes at least three leak holes, spacings between leak holes in each of the at least one perforated segment are the same, and M and N are positive integers greater than or equal to 1.

Abstract: Embodiments of the present invention disclose a communication method and apparatus, and a computer-readable storage medium. The method includes: An environment controller sends location information and a state pattern to a control board via an access network device. The control board adjusts a location and a state of the control board based on the location information and the state pattern. In embodiments of the present invention, a propagation environment of surrounding space may be optimized by adjusting the location and the state of the control board, to improve a throughput of a communication system.

Abstract: This application discloses a time reversal-based communication method and apparatus. The method includes: A first device receives first time reversal detection signals from a second device in M spatial channels from a first direction, a second direction, and a third direction, where M is a quantity of spatial channels on which the first device is capable of working, and the first direction, the second direction, and the third direction are perpendicular to each other. The first device determines N1 spatial channels in the M spatial channels based on the first time reversal detection signals. The first device communicates with the second device based on N1 first time reversal vector sequences through the N1 spatial channels, where the N1 first time reversal vector sequences are determined by the first device based on the first time reversal detection signals received in the N1 spatial channels from the three directions.

Abstract: This application provides an antenna detection method, an apparatus, a device, and a storage medium. The method includes: A first terminal device sends a first detection signal to a network device. The first detection signal is used to determine at least one first antenna sub-array corresponding to the first terminal device. A plurality of antenna sub-arrays of the network device include the at least one first antenna sub-array. A time interval at which the first detection signal is sent is related to spatial non-stationary coherence time. The first terminal device obtains first information from the network device. The first information indicates to perform information transmission through the at least one first antenna sub-array corresponding to the first terminal device.

Abstract: A modulo-based ADC implementation is provided and involves converting an input analog signal into phases of other M periodic analog reference signals based on one or more transfer functions, wherein M?2. The phase of each of the M reference signals comprises a folded signal corresponding to the input analog signal that is amplitude-folded to fall within a required amplitude range. This signal-to-phase conversion allows a modulo operation to be implemented over the input analog signal. Further, the M reference signals are used to obtain M discrete-time digital signals which, in turn, are used to obtain a digital representation of the input analog signal.

Abstract: This application provides a clock frequency determining method and a clock frequency determining apparatus. The method includes: An access network device receives a combined optical signal from a radio over fiber RoF device, where the combined optical signal is obtained by coupling an optical signal of a first frequency and an optical signal of a second frequency; the access network device converts the combined optical signal into an electrical signal; and the access network device sets a local clock frequency based on a signal frequency of the electrical signal and a first preset rule, where the signal frequency of the electrical signal is equal to an absolute value of a frequency difference between the first frequency and the second frequency.

Abstract: A wireless transmitter is configured to generate a first pilot signal having a first signal strength profile over a first plurality of frequency sub-bands and a second pilot signal having a second signal strength profile over a second plurality of frequency sub-bands and to transmit the first pilot signal and the second pilot signal via the communication channel to the wireless receiver. The first plurality of frequency sub-bands and the second plurality of frequency sub-bands comprise at least three common frequency sub-bands, wherein the common frequency sub-bands comprise at least one central common frequency sub-band and two boundary common frequency sub-bands, wherein a respective signal strength of the at least one central common frequency sub-band is smaller than a respective signal strength of the two boundary common frequency sub-bands.

Abstract: This application provides an example base station for an example wireless communication network and an example method. One example base station includes a central unit and a remote radio unit (RRU). The RRU includes one or more antennas. The RRU is coupled to the central unit via one or more optical transmission fibers. Each optical transmission fiber defines a respective downlink transmission channel for transmitting a respective downlink transmission signal from the central unit to the respective antenna of the RRU. The RRU is configured to provide a respective uplink feedback signal based on the respective downlink transmission signal via an uplink feedback channel to the central unit.

Abstract: A device, in a training phase, obtains Channel State Information (CSI) for one or more links between another device and at least one Access Point (AP), and in the training phase, estimates location information of the other device based on at least one geometric localization technique; and generates a database comprising CSI of the one or more links, each CSI being associated with an estimated location information. Further, a device, in a testing phase, obtains a database from another device, wherein the database comprises CSI of one or more links, each CSI being associated with an estimated location information, and in the testing phase, the device estimates CSI for one or more links between the device and at least one AP, and determine location information based on the estimated CSI of the one or more links and the database.

Abstract: A MIMO system comprises a remote radio unit (RRU) and central unit. The RRU comprises: a binary phase shift keying (BPSK) modulator, configured to modulate a BPSK waveform by a local oscillator (LO) signal to generate a stimulus signal, wherein the LO signal is derived from a downlink optical signal received via downlink radio over fiber (DL-ROF) from a central unit (CU); and an optical signal generator, in particular a laser, configured to generate an uplink optical signal based on the stimulus signal for transmission via uplink radio over fiber (UL-ROF) to the CU.

Abstract: A device, in a training phase, obtains Channel State Information (CSI) for one or more links between another device and at least one Access Point (AP), and in the training phase, estimates location information of the other device based on at least one geometric localization technique; and generates a database comprising CSI of the one or more links, each CSI being associated with an estimated location information. Further, a device, in a testing phase, obtains a database from another device, wherein the database comprises CSI of one or more links, each CSI being associated with an estimated location information, and in the testing phase, the device estimates CSI for one or more links between the device and at least one AP, and determine location information based on the estimated CSI of the one or more links and the database.

Abstract: A remote radio unit is for a base transceiver station. The remote radio unit includes: a noise generator configured to provide a RF noise signal having predefined statistical properties; a communication interface configured to transmit the RF noise signal as a stimulus signal over a radio-over-fiber uplink channel between the remote radio unit and a central unit of the base transceiver station for determining a pre-distortion of a target signal to be transmitted by the remote radio unit. The communication interface is further configured to receive the pre-distorted target signal over a ROF downlink channel between the remote radio unit and the central unit of the base transceiver station. The remote radio unit also has an antenna for transmitting the pre-distorted target signal received by the communication interface.

Abstract: This application provides an example base station for an example wireless communication network and an example method. One example base station includes a central unit and a remote radio unit (RRU). The RRU includes one or more antennas. The RRU is coupled to the central unit via one or more optical transmission fibers. Each optical transmission fiber defines a respective downlink transmission channel for transmitting a respective downlink transmission signal from the central unit to the respective antenna of the RRU. The RRU is configured to provide a respective uplink feedback signal based on the respective downlink transmission signal via an uplink feedback channel to the central unit.

Abstract: A MIMO system comprises a remote radio unit (RRU) and central unit. The RRU comprises: a binary phase shift keying (BPSK) modulator, configured to modulate a BPSK waveform by a local oscillator (LO) signal to generate a stimulus signal, wherein the LO signal is derived from a downlink optical signal received via downlink radio over fiber (DL-ROF) from a central unit (CU); and an optical signal generator, in particular a laser, configured to generate an uplink optical signal based on the stimulus signal for transmission via uplink radio over fiber (UL-ROF) to the CU.

Abstract: The disclosure relates to a method and an apparatus for locating a mobile device in a network system. For each pair of anchor stations, a receiver channel delay difference of receiving times of a first signal transmitted by a different anchor station and received at the anchor stations is determined. This receiver channel delay difference is used for compensating time difference of arrival among the mobile device and the pair of anchor stations. The compensated time difference of arrivals among the mobile device and the pair of anchor stations are used to determine the position of the mobile device.

Abstract: A remote radio unit is for a base transceiver station. The remote radio unit includes: a noise generator configured to provide a RF noise signal having predefined statistical properties; a communication interface configured to transmit the RF noise signal as a stimulus signal over a radio-over-fiber uplink channel between the remote radio unit and a central unit of the base transceiver station for determining a pre-distortion of a target signal to be transmitted by the remote radio unit. The communication interface is further configured to receive the pre-distorted target signal over a ROF downlink channel between the remote radio unit and the central unit of the base transceiver station. The remote radio unit also has an antenna for transmitting the pre-distorted target signal received by the communication interface.

Abstract: Embodiments of the present invention provide a signal processing method and apparatus. The method includes: performing M-way filtering on an input signal to obtain M filtered signals, performing extraction on M filtered signals separately to obtain M extracted signals, performing fast Fourier transform (FFT) on the M extracted signals separately to obtain M frequency-domain signals, and finally determining output signals according to the M frequency-domain signals. According to the embodiments of the present invention, signal filtering and extraction are performed and then FFT is performed.

Abstract: The present disclosure discloses a method, an apparatus, a device, and a system for antenna alignment. The method includes: performing, according to a target preset condition, adjustment processing on a phase and an amplitude of a signal that is transmitted by each antenna unit of a first antenna, and the second antenna is located within a coverage scope of the target beam; and determining that a difference between a horizontal angle of the target beam and a mechanical horizontal angle of a current mechanical location of the first antenna is a horizontal angle, that needs to be adjusted, of the first antenna, adjusting the mechanical horizontal angle and the mechanical pitch angle of the first antenna according to the horizontal angle that needs to be adjusted and the pitch angle that needs to be adjusted.

Abstract: Embodiments of the present invention disclose a method and an apparatus for transmitting information in a power communications system, and a system. The method is applied to a power communications system that uses at least two frequency bands for wireless communication, frequency band licensing statuses of the at least two frequency bands are different, and the method includes: determining a target frequency band from the at least two frequency bands based on an information type of to-be-sent information and a correspondence between the information type and a frequency band; and sending the to-be-sent information by using the target frequency band.