A transmitter can include a laser operable to output an optical signal; a digital signal processor operable to receive user data and provide electrical signals based on the data; and a modulator operable to modulate the optical signal to provide optical subcarriers based on the electrical signals. A first one of the subcarriers carriers carries first TDMA encoded information and second TDMA encoded information, such that the first TDMA encoded information is indicative of a first portion of the data and is carried by the first one of the subcarriers during a first time slot, and the second TDMA encoded information is indicative of a second portion of the data and is carried by the first one of the subcarriers during a second time slot. The first TDMA encoded information is associated with a first node remote from the transmitter and the second TDMA encoded information is associated with a second node remote from the transmitter. A second one of the subcarriers carries third information that is not TDMA encoded, the third information being associated with a third node remote from the transmitter. A receiver and system also are described.

A radio communication system for duplex communication comprising an optical carrier generator for generating optical carrier signals, a local oscillator (LO) for generating an electrical signal in a radio communication band, an information signal source, electro-optic modulators driven directly at an input electrical port by said information signal and said LO signal to modulate a portion of said optical carrier signal to form a modulated portion being an optical band information signal for transmission over an optical link; and a photodetector remote from said electro-optic modulators for receiving said transmitted optical band information signal from said optical link, and directly generating an electrical signal that is up-converted for radio transmission, or down-converted to a baseband frequency.

A MIMO basestation for a cellular communications system comprises a remote indoor processing facility coupled to an outdoor RF tower via optical fibers. The remote indoor processing facility includes a bank of RF modulators to modulate signal streams; a remote MIMO transmitting processor that includes a remote digital beam-forming network to transform the modulated signal streams into transmit beam signals; a pre-processor to perform a wavefront multiplexing transform on the transmit beam signals to generate wavefront multiplexed beam signals, each of the wavefront multiplexed beam signals being a linear combination of the transmit beam signals; and RF-to-optical drivers to perform optical modulating functions on the wavefront multiplexed beam signals to generate optical waveform streams.

An ROF communication remote machine and an ROF system are disclosed. The machine comprises a first packaging module and a second packaging module. The first packaging module comprises a first branch and a second branch The first branch is used for converting a downlink optical signal, and sending the downlink electrical signal to the second packaging module. The second branch receives the downlink electrical signal, converts the downlink electrical signal into a downlink optical signal, sends the downlink optical signal to the local machine, receives an uplink electrical signal, and sends the uplink electrical signal to the local machine. The second packaging module is used for amplifying the power of the downlink electrical signal, filtering the downlink electrical signal, then feeding back the downlink electrical signal to another component, receiving the uplink electrical signal, and sending the uplink electrical signal to the second port.

A distributed antenna system comprises: one or more access units configured to receive multiple downlink radio frequency signal sets, and further configured to convert the multiple downlink radio frequency signal sets into multiple downlink optical signal sets; a first wavelength division multiplexing unit configured to multiplex the multiple downlink optical signal sets to generate a first wavelength division multiplexing optical signals; a first wavelength division demultiplexing unit configured to demultiplex the first wavelength division multiplexing optical signals to obtain the multiple downlink optical signal sets; a first optical fiber, coupled between the first wavelength division multiplexing unit and the first wavelength division demultiplexing unit, and configured to transmit the first wavelength division multiplexing optical signal; and multiple first remote units coupled to the first wavelength division multiplexing unit, and configured to convert the multiple downlink optical signal sets into the multiple downlink radio frequency signal sets for transmission.

The present disclosure provides a data transceiving method, a data transceiving device, a wavelength configuration method and a wavelength configuration device. The data transceiving method includes that a first optical module receives control information sent by a second optical module; the first optical module adjusts transmission and receiving wavelengths according to the control information; and the first optical module executes transmission and receiving of data with the second optical module according to the adjusted transmission and receiving wavelengths.

n wavelengths set such that delay differences between optical signals due to wavelength dispersion in an optical fiber between accommodation and base stations are at equal intervals are assigned to n antenna elements of the base station which are at predetermined intervals. The accommodation station adjusts the phases of optical signals of the wavelengths or modulated signals that modulate the optical signals such that the amounts of phase shift of their RF signals are at predetermined intervals. The accommodation station transmits beacon signals multiple times while varying a transmission phase shift interval α.sub.1 and the terminal transmits beacon number information of a beacon signal selected based on received power multiple times. The accommodation station varies a reception phase shift interval α.sub.2 for each piece of beacon number information to determine a reception phase shift interval α.sub.2 which maximizes the received power and determines the transmission phase shift interval α.sub.1 based on the beacon number information received from the terminal.

A method may include obtaining a topology of an optical network. The topology may indicate multiple optical links within the optical network. The method may also include obtaining a routing metric for each of the optical links. The routing metric may be used in selecting routes through the optical network along the multiple optical links. The method may further include obtaining a signal noise tolerance of an optical signal to be routed through the optical network and adjusting routing metrics of one or more of the multiple optical links based on the signal noise tolerance of the optical signal. The method may also include after the routing metrics of the one or more of the multiple optical links are adjusted, determining a route for the optical signal through the optical network along two or more of the multiple optical links based on the routing metrics of the multiple optical links.

A method may include obtaining a topology of an optical network. The topology may indicate multiple optical links within the optical network. The method may also include determining a signal noise tolerance for each of multiple optical signal types supported by the optical network and obtaining an optical noise for each of the multiple optical links. The method may also include determining a number of the multiple optical signal types that each of the multiple optical links is able to support based on the optical noise for each of the optical links and the signal noise tolerance for each of the multiple optical signal types and ranking the multiple optical links based on the number of the multiple optical signal types that each of the optical links is able to support.

A first node of a network includes a quantum transmitter, a classical transceiver, and an initial-key generator that cooperate with a second node to transmit an initial key via the quantum transmitter. The first node includes a key-series generator that (i) encrypts a first unencrypted key of a series of unencrypted keys to generate a first encrypted key of a series of encrypted keys and (ii) encrypts each subsequent unencrypted key of the series of unencrypted keys with a preceding unencrypted key of the series of unencrypted keys to generate a subsequent encrypted key of the series of encrypted keys. The encrypted keys are transmitted to the second node. The first node includes one or both of a decryptor and an encryptor. The decryptor decrypts encrypted data using a last unencrypted key of the series of unencrypted keys. The encryptor encrypts unencrypted data using the last unencrypted key.