Abstract: The present disclosure is a novel utility of a software defined radio (SDR) based Distributed Antenna System (DAS) that is field reconfigurable and support multi-modulation schemes (modulation-independent), multi-carriers, multi-frequency bands and multi-channels. The present disclosure enables a high degree of flexibility to manage, control, enhance, facilitate the usage and performance of a distributed wireless network such as flexible simulcast, automatic traffic load-balancing, network and radio resource optimization, network calibration, autonomous/assisted commissioning, carrier pooling, automatic frequency selection, frequency carrier placement, traffic monitoring, traffic tagging, pilot beacon, etc.

Abstract: An automatic gain control system for a receiver, including: an automatic gain control loop (40) adapted to be coupled to both a first transimpedance amplifier (12) coupled to a first analog-to-digital converter (14) forming a first tributary and a second transimpedance amplifier (12) coupled to a second analog-to-digital converter (14) forming a second tributary; and an offset gain control voltage to gain balance a transimpedance amplifier gain of the first tributary and a transimpedance amplifier gain of the second tributary. The automatic gain control loop can be analog. Also, the automatic gain control loop can be implemented in hardware or firmware.

Abstract: The present disclosure is a novel utility of a software defined radio (SDR) based Distributed Antenna System (DAS) that is field reconfigurable and support multi-modulation schemes (modulation-independent), multi-carriers, multi-frequency bands and multi-channels. The present disclosure enables a high degree of flexibility to manage, control, enhance, facilitate the usage and performance of a distributed wireless network such as flexible simulcast, automatic traffic load-balancing, network and radio resource optimization, network calibration, autonomous/assisted commissioning, carrier pooling, automatic frequency selection, frequency carrier placement, traffic monitoring, traffic tagging, pilot beacon, etc.

Abstract: A system and a method to wirelessly synchronize, monitor, or communicate, or a combination thereof, amongst sensors (e.g., sensors, hubs, sensor controllers, etc.) in a Bluetooth Low Energy-based microlocation system. The system or method, or both, may use the BLE hardware (e.g., transmitters, receivers, antennas, etc.) to interleave a communications protocol within the connection interval gaps of the BLE protocol used to communicate with devices.

Abstract: A system (100) for communicating a presence of a device via a light source (110) configured to emit light comprising an embedded code is disclosed. The system (100) comprises: a controller (102) comprising: a receiver (106) configured to receive a response signal from a first device (120), which response signal comprises an identifier of the first device (120), and which response signal is indicative of that the embedded code has been detected by the first device (120), and a processor (104) configured to correlate the embedded code with the identifier of the first device (120), such that the embedded code is representative of the identifier of the first device (120).

Abstract: A synchronization detection method of a repeater comprises receiving a communication signal comprising a plurality of synchronization signal blocks respectively belonging to different frequency ranges, determining a priority of a frequency range in which the plurality of synchronization signal blocks are to be detected based on signal level for each frequency range and detecting a synchronization signal block included in each frequency range according to the determined priority.

Abstract: Embodiments of this application disclose a communication method and an apparatus, and relate to the communications field, to resolve a problem of how to simultaneously perform transmission by using a plurality of light sources and increase transmission efficiency in a multi-light source scenario in an optical camera communications system. A specific solution is: generating N physical frames, where each of the physical frames includes a preamble, a mode indication, and valid data, the mode indication is used to indicate a sending mode of N light sources, the sending mode is a diversity mode or a multiplexing mode, and N is a positive integer greater than or equal to 2; and sending the N physical frames by using the N light sources, where one light source sends one physical frame. The embodiments of this application are used in an optical camera communication process.

Abstract: Joint power allocation and cell formation for energy efficient (EE) visible light communication (VLC) networks is described. A set of rules for clustering users and then associating all the access points (APs) to the clustered users based on a proposed metric is developed. The energy efficiency is maximized by allocating power to users based on quality of service (QoS) constraints. The present disclosure jointly allocates the power and decides which APs must participate in communication and which ones must be switched off to minimize inter-cell interference. Numerical results demonstrate a significant improvement in energy efficiency compared to the traditional methods of clustering and AP assignment.

Abstract: Joint power allocation and cell formation for energy efficient (EE) visible light communication (VLC) networks networks is described. A set of rules for clustering users and then associating all the access points (APs) to the clustered users based on a proposed metric is developed. The energy efficiency is maximized by allocating power to users based on quality of service (QoS) constraints. The present disclosure jointly allocates the power and decides which APs must participate in communication and which ones must be switched off to minimize inter-cell interference. Numerical results demonstrate a significant improvement in energy efficiency compared to the traditional methods of clustering and AP assignment.

Abstract: Joint power allocation and cell formation for energy efficient (EE) visible light communication (VLC) networks is described. A set of rules for clustering users and then associating all the access points (APs) to the clustered users based on a proposed metric is developed. The energy efficiency is maximized by allocating power to users based on quality of service (QoS) constraints. The present disclosure jointly allocates the power and decides which APs must participate in communication and which ones must be switched off to minimize inter-cell interference. Numerical results demonstrate a significant improvement in energy efficiency compared to the traditional methods of clustering and AP assignment.

Abstract: A flickerless LED driver device includes a transformer having a primary coil for receiving an alternating-current (AC) voltage, and a secondary coil for generating a first induced voltage induced from the primary coil; a secondary coil circuit for receiving the first induced voltage and applying a first direct-current (DC) voltage to an LED module; a current sensor for sensing a driving current flowing through the secondary coil circuit from the secondary coil; a current controller for receiving a signal about the driving current and generating a control signal for controlling an emission current flowing through the LED module; and a ripple attenuator connected to the LED module to receive a visual light communication (VLC) signal and the control signal, control an emission current corresponding to the VLC signal to flow through the LED module, and suppress ripple of the emission current.

Abstract: An optical transmission module that converts an electric signal to an optical signal and outputs the optical signal, including: a package; a plurality of light-emitting elements each emitting light in the interior of the package; a plurality of light-receiving elements each including a light-receiving surface on which a portion of the light is incident in the interior of the package, for monitoring light outputs of the plurality of light-emitting elements; and light-shielding members provided on the plurality of light-receiving elements while avoiding the light-receiving surfaces.

Abstract: A positioning method based on a visible light source, a mobile terminal, and a controller. The method includes acquiring, by a visible light source controller, geographical position attribute information of a position at which a visible light source array is located, determining, by the visible light source controller according to a preset correspondence between geographical position attribute information of a position at which a visible light source array is located and a visible light source array pattern, a visible light source array pattern corresponding to the acquired geographical position attribute information, and controlling, by the visible light source controller according to the determined visible light source array pattern, the luminance state of each visible light source included in the visible light source array. Hence the method reduces the complexity of a positioning process.

Abstract: A system for monitoring a machine includes first and second mobile units. The first mobile unit includes an emitter, a clock in communication with the emitter, and a sensor in communication with the clock. The second mobile unit includes a detector, a clock in communication with the detector, and a sensor in communication with the clock. The detector of the second mobile unit is configured to detect a signal from the emitter of the first mobile unit, and the clocks in the first and second mobile units are configured to be synchronized in response to the detection of the signal.

Abstract: Systems and methods presented herein provide for improved access to data. In one embodiment, a communication system includes an RF communication link that is operable to receive first communications from a mobile device (e.g., a cell phone, tablet computer, laptop computer, or other “user equipment”). The communication system also includes a processor operable to determine a location of the mobile device based on the first communications and a plurality of directional communication links. Each directional communication link is operable to transfer data to the mobile device based on the location of the mobile device as determined by the processor. The processor is also operable to coordinate the transfer of data from each of the directional communication links to the mobile device.

Abstract: The disclosure provides an optical module. In the optical module, emitters of a first PNP type triode and a second PNP type triode connected with a power source are high-level always, when a bias pin of a laser transmitter driver chip is high-level, bases of the two PNP type triodes are both high-level and in an OFF state, no current flows to the bias pin and a laser transmitter, and the laser transmitter does not emit light; when the bias pin of the laser transmitter driver chip is low-level, the bases of the two PNP type triodes are both low-level and in an ON state, the current flows to the bias pin and flows from a positive terminal of the laser transmitter, and the laser transmitter emits light.

Abstract: A method and apparatus for controlling Zigbee wireless lighting are disclosed. The apparatus for controlling Zigbee wireless lighting includes an address management unit, a packet conversion unit, and a client unit. The address management unit detects a Zigbee wireless address, corresponding to a light ID included in a command received from a user terminal, in an address management table. The packet conversion unit converts the command into a Zigbee light link (ZLL)-based packet. The client unit transfers the ZLL-based packet to Zigbee wireless illumination light corresponding to the Zigbee wireless address in order to control the Zigbee wireless illumination light.

Abstract: Certain features relate to systems and methods for jointly optimizing a radio access network (RAN) and distributed antenna system (DAS). A joint RAN-DAS self-optimizing network (SON) entity can determine target operations and management parameters based on operations and management parameters specific to the DAS and operations and management parameters specific to the RAN. The joint RAN-DAS-SON entity can optimize the RAN and DAS using the target operations and management parameters. Jointly optimizing the RAN and the DAS can improve the capacity characteristics, coverage characteristics, or the performance characteristics of the RAN and DAS. In some aspects, the joint RAN-DAS-SON entity can optimize the RAN and DAS by re-allocating power levels of downlink signals transmitted by remote units of the DAS to compensate for underutilized carrier signals in situations of low traffic load.

Abstract: A network, a Visible Light Communications (VLC) controller, and a method relate to a network architecture splitting frame processing functionality between Light Fidelity (LiFi) Access Points (APs) and a VLC controller or virtualized controller. In such configurations, the LiFi APs are so-called thin devices that may be widely deployed through an infrastructure to concurrently provide illumination and network access via VLC protocols such as IEEE 802.15.7 or variants thereof.

Abstract: A beam forming antenna device emitting a predetermined free space energy pattern, the device including: an optical signal source having predetermined wavelength characteristics; an optical modulator for modulating predetermined wavelengths of the optical signal source to produce a modulated signal source including frequency sideband components; a dispersion element for spreading and projecting the modulated signal source in a wavelength dependant manner onto a relative phase manipulation element; a relative phase manipulation element manipulating the relative phase of the modulated signal source in a predetermined manner, said phase manipulation element further amplitude modulating predetermined wavelengths of said modulated signal source and outputting a predetermined groupings of wavelengths on a series of output ports; optical to electrical conversion means converting the amplitude of the optical signal on said output ports to a corresponding electrical signal; and a series of irradiating antenna elements

Abstract: Disclosed herein is a visible light communication method and device using a DMX-512 network. In the visible light communication method, dimming data packets are received. Visible Light Communication (VLC) data packets are generated. The dimming data packets and the VLC data packets are scheduled so that one or more of the VLC data packets are transmitted to Light Emitting Diode (LED) lighting devices connected over a Digital Multiplex (DMX)-512 network between transmission times of the dimming data packets.

Abstract: A radio-over-fiber (RoF) hybrid wired/wireless transponder is disclosed that is configured to provide both wireless and wired communication between a hybrid head-end and one or more client devices. The hybrid transponder includes optical-to-electrical (O/E) and electrical-to-optical (E/O) conversion capability and is configured to frequency multiplex/demultiplex electrical “wired” signals and electrical “wireless” signals. The electrical wireless signals are wirelessly communicated to the client device(s) via a multiple-input/multiple-output (MIMO) antenna system within a cellular coverage area. The electrical wired signals are communicated to the client device(s) via a wireline cable that plugs into a wireline cable port on the transponder. The hybrid RoF system includes a hybrid head-end capable of transmitting and receiving wired and wireless optical signals, and an optical fiber cable that is optically coupled to the hybrid head-end and to at least one hybrid transponder.

Abstract: A free-space, decentralized, distributed computing network may comprise at least one free-space dynamic memory unit, at least one free-space processing unit, at least one free-space static memory unit, and at least one free-space communications link. The free-space dynamic memory unit may store data. The free-space processing unit may process the data, stored by the free-space dynamic memory unit, into information. The free-space static memory unit may provide operational instructions to the free-space dynamic memory unit and to the free-space processing unit. The free-space communications link may connect in the free-space the free-space dynamic memory unit, the free-space processing unit, and the free-space static memory unit. The free-space dynamic memory unit, the free-space processing unit, and the free-space static memory unit may each comprise at least one tracking device, and a transducer, transmitter, and/or receiver.

Abstract: A switched wireless system is used to increase the range of peer-to-peer communications. The optically-switched fiber optic communication system includes a head-end unit (HEU) having a switch bank. Cables couple the HEU to one or more remote access points in different coverage areas. The switch bank in the HEU provides a link between the remote access points in the different coverage areas such that devices in the different cellular coverage areas communicate with each other. By using the switched communication system, the range and coverage of communication between devices may be extended such that devices in different coverage areas and devices using different communication protocols can communicate.

Abstract: For use in visible light communication (VLC), synchronization with multiple topology support while transmitting an extended preamble includes transmitting a two-part preamble sequence. The preamble sequence includes one or more repetitions of a fast locking pattern (FLP) configured to be used clock synchronization, and one or more repetitions of a topology dependent pattern (TDP) configured to be used to distinguish a plurality of VLC topologies. The method for transmitting an extended preamble includes generating an extended preamble and transmitting the extended preamble during a receive or idle mode for maintaining visibility support and for better synchronization performance.

Abstract: Systems and methods for visible light communication are disclosed. In part, illumination devices and related systems and methods are disclosed that can be used for general illumination, lighting control systems, or other applications. The illumination devices synchronize preferentially to the AC mains to produce time division multiplexed channels in which control information can be communicated optically by the same light source that is producing illumination. Such illumination devices preferentially comprise LEDs for producing illumination, transmitting data, detecting ambient light, and receiving data, however, other light sources and detectors can be used. The physical layer can be used with a variety of protocols, such as ZigBee, from the Media ACcess (MAC) layer and higher.

Abstract: A visible light communication method and terminal are provided for communicating with a visible light coordinator which discriminates between at least one communication area cell that includes at least one light source and a boundary area positioned between the communication area cell and another communication area cell adjacent to the communication cell area, and which provides time division visible light communication. Data of the visible light communication terminal is received from the visible light coordinator using a first time slot in a first communication area cell determined according to a position of the visible light communication terminal. The visible light coordinator is communicated with using a second time slot assigned from the visible light coordinator, when the visible light communication terminal is located in a boundary area of the first communication area cell. The second time slot has not been assigned to the visible light communication terminal.

Abstract: An apparatus comprises a platform, an optical transmitter associated with the platform, an optical detector associated with the platform, a sensor associated with the platform, a phase-locked loop circuit, and a processor unit associated with the platform. The optical transmitter is configured to transmit first optical signals. The optical detector is configured to receive optical signals. The phase-locked loop circuit is configured to indicate a presence of second optical signals in the optical signals indicating a time interval to transmit information in the first optical signals. The processor unit is electrically connected to the optical detector, the optical transmitter, and the sensor. The processor unit is associated with the phase-locked loop circuit. The processor unit is configured to transmit the information in the first optical signals using the optical transmitter during the time interval.

Abstract: An interconnect system has an optical transmitter mounted on a first circuit board and an optical receiver mounted on a second circuit board. The optical receiver can be nominally aligned to receive an optical signal through free space from the optical transmitter. Further, the optical receiver includes one or more light detectors, and an optical antenna coupled to direct incident light into the one or more light detectors.

Abstract: A time-sharing Visible Light Communication (VLC) system is provided. Two or more light sources transmit data received from one or more VLC terminals located in its service area to a communication control device, and transmits data received from the communication control device to the one or more VLC terminals. The communication control device determines and groups at least one of the two or more light sources to be included in a cell according to a generated user service, maps the grouped at least one light source to the cell, allocates a time slot used to provide the user service to the cell, transmits data associated with the user service to at least one of the one or more VLC terminals through the at least one light source mapped to the cell using the allocated time slot, detects a location of the at least one VLC terminal located in a service area of the cell on a real-time basis, and remaps the cell according to the detected location.

Abstract: The invention presents a method and a device for bidirectional IR data transfer between a medical treatment table, particularly an operating table (10a to 10d), and an operator control device (12a to 12d) which are subscribers in the IR data transfer and which each comprise an IR transmitter and an IR receiver, where the data to be transferred by a subscriber (10a to 10d, 12a to 12d) are split into data blocks which are transmitted in succession, with a respective break being observed between the transmission of the individual data blocks, and where data from another subscriber are transmitted within the breaks.

Abstract: The present disclosure provides radio frequency (RF)-based OTN systems and methods. This includes a framework to carry services over RF-based links without using SONET/SDH or asynchronous radio. In an exemplary embodiment, the present disclosure utilizes an OTN framework over RF. Additionally, the present disclosure can also apply to other non-OTN frameworks such as an extended Ethernet frame with forward error correction (FEC) over RF-based links. The present disclosure combines existing OTN FEC with a radio FEC or with an over-the-air FEC to reduce the OTN FEC. Additionally, the present disclosure utilizes unused overhead to communicate RF data rates between radios.

Abstract: A method of establishing a system delay time and a frame length in a Time Division Duplexing (TDD) system includes adjusting time lengths of an uplink (UL) frame, a downlink (DL) frame, a Transmit/receive Transition Gap (TTG), and a Receive/transmit Transition Gap (RTG); a Base Station (BS) transmitting a DL frame and receiving a UL frame; and a Mobile Station (MS) receiving the DL frame and transmitting the UL frame.

Abstract: An apparatus and a method for providing synchronized data by using visible light communication includes, receiving a synchronization channel from a mobile communication base station using a specific mobile communication network, by a Light Emitting Diode (LED) lighting; analyzing the received synchronization channel, and extracting a synchronization signal for synchronizing the LED lighting with at least one LED lighting adjacent to the LED lighting; selecting a specific time slot of the synchronization signal based on IDentifications (IDs) of the LED lightings; and including a data frame of the LED lighting in the specific time slot, and transmitting the specific time slot, which includes the data frame of the LED lighting, to a mobile terminal.

Abstract: Various approaches for a traffic control preemption system that includes a receiver, a light emitter, and control circuitry. The receiver includes a photodetector and circuitry that produces a number of electrical pulses in response to each detected light pulse. For each detected light pulse the number of electrical pulses represents a level of radiant power of the light pulse, and a threshold number of electrical pulses and an activation frequency at which the threshold number of electrical pulses is repeated activates preemption. The control circuitry is coupled to the light emitter and controls the light emitter to emit bursts of light pulses. Each burst includes at least two light pulses and a frequency of light pulses in each burst and a frequency of the bursts cause the receiver to produce at least the threshold number of electrical pulses at the activation frequency and activate the preemption.

Abstract: In the field of signal processing technologies, a microwave transmission apparatus, a signal processing method and device in a microwave transmission apparatus are provided, which are capable of improving the signal-to-noise ratio of the service signal and the reliability of the communication signal, and increasing the distance between an indoor unit (IDU) and an outdoor unit (ODU). In the technical solutions, a signal processing method in a microwave transmission apparatus includes: directly multiplexing at least a service signal and a non-service signal, and converting the multiplexed electric signal into a multiplexed optical signal; and sending the multiplexed optical signal to an ODU.

Abstract: Systems and methods for visible light communication are disclosed. In part, illumination devices and related systems and methods are disclosed that can be used for general illumination, lighting control systems, or other applications. The illumination devices synchronize preferentially to the AC mains to produce time division multiplexed channels in which control information can be communicated optically by the same light source that is producing illumination. Such illumination devices preferentially comprise LEDs for producing illumination, transmitting data, detecting ambient light, and receiving data, however, other light sources and detectors can be used. The physical layer can be used with a variety of protocols, such as ZigBee, from the Media ACcess (MAC) layer and higher.

Abstract: Various approaches for activating a traffic control preemption system. The traffic control preemption system has a receiver with a photodetector and circuitry that produces a number of electrical pulses in response to each detected light pulse. For each detected light pulse the number of electrical pulses represents a level of radiant power of the light pulse. A threshold number of electrical pulses and an activation frequency at which the threshold number of electrical pulses is repeated activates preemption. Control circuitry is coupled to a light emitter and controls the light emitter to emit bursts of light pulses. Each burst includes at least two light pulses and the control circuitry controls the frequency of light pulses in each burst and the frequency of the bursts to cause the receiver to produce at least the threshold number of electrical pulses at the activation frequency and activate the preemption.

Abstract: The present disclosure provides radio frequency (RF)-based OTN systems and methods. This includes a framework to carry services over RF-based links without using SONET/SDH or asynchronous radio. In an exemplary embodiment, the present disclosure utilizes an OTN framework over RF. Additionally, the present disclosure can also apply to other non-OTN frameworks such as an extended Ethernet frame with forward error correction (FEC) over RF-based links. The present disclosure combines existing OTN FEC with a radio FEC or with an over-the-air FEC to reduce the OTN FEC. Additionally, the present disclosure utilizes unused overhead to communicate RF data rates between radios.

Abstract: A time-sharing Visible Light Communication (VLC) system is provided. Two or more light sources transmit data received from one or more VLC terminals located in its service area to a communication control device, and transmits data received from the communication control device to the one or more VLC terminals. The communication control device determines and groups at least one of the two or more light sources to be included in a cell according to a generated user service, maps the grouped at least one light source to the cell, allocates a time slot used to provide the user service to the cell, transmits data associated with the user service to at least one of the one or more VLC terminals through the at least one light source mapped to the cell using the allocated time slot, detects a location of the at least one VLC terminal located in a service area of the cell on a real-time basis, and remaps the cell according to the detected location.

Abstract: The present invention discloses a method for transmitting signal between a central channel processing Main Unit (MU) and one or more Remote Radio Units (RRUs) by using SDH/OTN in Centralized Base Transceiver Station system using remote radio head (RRH) technology.

Abstract: A free space optical bus system and method are provided for connecting two units of circuitry across a free space gap. A first unit of circuitry includes a multiplexer that combines a plurality of bus signals to obtain an electronic combined signal and a laser that is driven by the electronic combined signal to transmit an optical signal. A second unit of circuitry is separated from the first unit of circuitry by a free space gap. The second unit of circuitry includes a photodetector that receives the optical signal and transforms it into an electronic composite signal and a demultiplexer that divides the composite signal into a plurality of constituent signals.

Abstract: A method and apparatus for transmitting data to an Access Point (AP) and a Mobile Station (MS) in a Time Division Duplex (TDD) optical repeater. A main donor generates a control frame for controlling a remote, upon receipt of data from the AP, and transmits the control frame to the remote during a non-downlink transmission period. The remote analyzes the control frame received from the main donor, detects sync information about a downlink signal and an uplink signal, and remote control information from the analyzed control frame, performs a control operation according to the detected remote control information, and generates a status frame for notifying the main donor of the status of the remote upon receipt of data from the MS. The status frame is transmitted from the remote to the main donor during a non-uplink transmission period.

Abstract: Disclosed are a method and a system for generating switching control signal separating transmission signal on an access point and a mobile communication terminal in an optical repeater employing, for example, a TDD scheme. The method includes the steps of generating a control signal for generating a switching control signal in transmitting data from the AP and transmitting the control information to a remote during an idle time interval, detecting synchronization information on the downlink signal and time-delay information from the control information, delaying a time interval between the synchronization information and a starting point of the downlink signal, generating the switching control signal for the downlink signal according to the transmission time information of the downlink signal, and performing a switching operation according to the switching control signal and setting a downlink path.

Abstract: A method and system for conveying contextually relevant information to a wireless client are disclosed. More particularly, a transmitter transmits a diffuse infrared signal to a client having an IrDA compliant communication interface. The transmitter communicates with the client by making a link layer in the transmitter compliant with an IrDA link layer running on the client. To perform communication, data is received at the transmitter from a service provider. The data is formatted into an IrDA compliant diffuse infrared signal and transmitted to the client. The client receives the data and parses it to extract contextually relevant information contained therein. The client may reply to the transmitter if a user of the client is interested in a service offered by the service provider. If the service provider receives a reply from the client, the service is made available to client.

Abstract: A method and apparatus for processing a data signal for transmission to a remote device transmits at least two synchronized copies of the data signal, in optical form, in different directions. To that end, the data signal first is synchronized to a clock signal to produce a composite signal. The composite signal then is converted to an optical signal, which is referred to as an “outgoing signal.” A plurality of copies of the outgoing signal then are transmitted. At least two copies of the outgoing signal are transmitted in different directions.

Abstract: The centralized optical-fiber-based wireless picocellular system includes one or more service units at a central head-end station. The one or more service units are optically coupled to one or more transponders via respective one or more optical fiber RF communication links. The transponders are each adapted to provide within the associated picocell electromagnetic RF service signals from different service units, and receive electromagnetic RF service signals from any client device within the picocell. The service signal from the particular client device is sent over the optical fiber RF communication link back to one or more service units. The transponders are arranged along the length of one or more optical fiber cables, which can be distributed throughout a building infrastructure. This creates a picocellular coverage area that provides a number of different wireless services relative to the building infrastructure.

Abstract: A repeating apparatus and method using wireless optical transmission is disclosed. The repeating apparatus includes a donor device for transmitting two identical copies of an optical signal by receiving a RF signal from a base station and electro-optic converting the RF signal to an optical signal, and for transmitting a RF signal by receiving two identical copies of the optical signal and optic-electro converting the optical signal to a RF signal; and a coverage device for transmitting a RF signal to a mobile communication terminal by receiving two identical copies of the optical signal from the donor device and optic-electro converting the two identical copies of the optical signal to the RF signal, and transmitting two optical signals to the donor device by receiving the RF signal from the mobile communication terminal and elector-optic converting the RF signal to the optical signal.

Abstract: A novel optical time division multiplexing (OTDM) module based on hybrid-integrated optical chips is disclosed. An integrated modulator chip generates optical RZ signal streams which are then interleaved in an integrated time-delay chip to produce an OTDM signal. The integrated modulator chip is coupled and secured to the integrated time-delay chip via a suitable optical index-matching layer or collimating lenses. Such an approach alleviates the stability problems offered by conventional fiber-based OTDM technology and aids in reducing the size and complexity as well as lowering the cost for the assembly. Furthermore, the time-delay chip of the present invention offers fine tuning capabilities thereby allowing for slight adjustments in the interleaving of optical signal streams when non-standard data transmission rates are required.

Abstract: A method for communicating information includes modulating a communications signal by orthogonal frequency domain modulation and transmitting the communication signal by a laser and/or light emitting diode carrier signal.