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.

Abstract: Embodiments of the present invention disclose a data transmission method and a related apparatus, which are used to implement compression of data transmitted on a backhaul to increase throughput of the backhaul. The method in the embodiments of the present invention includes: parsing a received Internet Protocol (IP) data packet to obtain a transmission network protocol header, a transmission tunneling protocol header, a user data protocol header, and user application layer data; compressing the transmission tunneling protocol header, the user data protocol header, and the user application layer data to obtain a compressed transmission network protocol payload; using the transmission network protocol header to encapsulate the compressed transmission network protocol payload to obtain a compressed IP data packet; and sending the compressed IP data packet to a decoding device in a core network or in a base station.

Abstract: A method for returning a base station signal and a base station for implementing the method. The base station includes a first return unit located in a radio frequency system and a second return unit located in a baseband processing system. The first return unit is configured to perform analog modulation on an uplink analog signal of a first bandwidth to obtain an uplink analog signal of a second bandwidth, and send the uplink analog signal of the second bandwidth to the second return unit, where the second bandwidth is larger than the first bandwidth. The second return unit is configured to receive the uplink analog signal of the second bandwidth, demodulate the uplink analog signal of the second bandwidth to obtain the uplink analog signal of the first bandwidth.

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 disclosure disclose a wireless transceiver. The wireless transceiver includes a second control switch, and the second control switch may selectively connect a signal output end of a coupler or a signal output end of a low noise amplifier LNA to a signal input end of the down converter. Therefore, when the signal output end of the coupler is connected to the down converter, the coupler, the down converter, and the analog-to-digital converter ADC form an observer; when the second control switch connects the signal output end of the low noise amplifier LNA to the signal input end of the down converter, a transceiver antenna, the low noise amplifier LNA, the down converter, and the analog-to-digital converter ADC form a receiver. Therefore, the embodiments of the present disclosure can greatly save hardware costs of a system for implementing an observer circuit.

Abstract: The present invention discloses a radio base station and a method for clock synchronization of the radio base station. The radio base station may include a base station outdoor apparatus including an adapter, a ground service antenna, and a satellite antenna. A base station indoor apparatus includes a satellite signal processing module configured to perform decoding processing on a satellite radio frequency signal received by the satellite antenna to obtain a satellite service signal. The satellite antenna and the ground service antenna are connected to the adapter. The adapter is configured to couple the signals received by the satellite antenna and ground service antenna, and transmit a coupled signal to the base station indoor apparatus through a first data cable.