Abstract: A method for laser chirp precompensation includes modulating an amplitude of an optical signal, in response to an amplitude of one of (i) a chirp-compensated signal generated via distortion of an original modulated signal according to an inverse of a chirp-response function of a laser and (ii) a first signal derived from the chirp-compensated signal, to yield an amplitude-modulated optical signal. The method also includes modulating a phase of the amplitude-modulated optical signal in response to a phase of one of (i) the chirp-compensated signal and (ii) a second signal derived from the chirp-compensated signal to yield a chirp-compensated optical signal.

Abstract: A skew compensation system for a coherent optical communication network includes a transmitter modulator having a first driver input for receiving a first signal from a first channel, a second driver input for receiving a second signal from a second channel, a source input for receiving a continuous wave source signal, and a modulation output in communication with an optical transport medium of the network. The system further includes a tunable delay line disposed between the second channel and the second driver input for inserting a pre-determined training sequence onto the second signal prior to the second driver input, and a processor for determining a skew amount between the second signal at the second driver input and the first signal at the first driver input, calculating a pre-compensation value corresponding to the skew amount, and reducing the skew amount at the modulation output according to the pre-compensation value.

Abstract: An echo cancellation method includes steps of (a) extracting phase-distortion estimates, (b) reconstructing an echo signal, (c) generating a clean signal, and (d) producing a primary signal. Step (a) includes extracting, from a first phase signal, a plurality of phase-distortion estimates, the first phase signal having been estimated from an echo-corrupted signal received at a first coherent transceiver of a coherent optical network. Step (b) includes reconstructing an echo signal from the plurality of phase-distortion estimates and a transmitted signal transmitted by the first coherent transceiver. Step (c) includes generating a clean signal as a difference between the reconstructed echo signal and the first phase signal. Step (d) includes producing a primary signal by mapping each of a plurality of clean-phase estimates of the clean signal to one of a plurality of constellation symbols associated with a modulation scheme of the primary signal.

Abstract: An optical network communication system includes an optical hub, an optical distribution center, at least one fiber segment, and at least two end users. The optical hub includes an intelligent configuration unit configured to monitor and multiplex at least two different optical signals into a single multiplexed heterogeneous signal. The optical distribution center is configured to individually separate the at least two different optical signals from the multiplexed heterogeneous signal. The at least one fiber segment connects the optical hub and the optical distribution center, and is configured to receive the multiplexed heterogeneous signal from the optical hub and distribute the multiplexed heterogeneous signal to the optical distribution center. The at least two end users each include a downstream receiver configured to receive one of the respective separated optical signals from the optical distribution center.

Abstract: An optical access network includes an optical hub having at least one processor, and a plurality of optical fiber strands. Each optical fiber strand has a first strand end connected to the optical hub. The network further includes a plurality of nodes connected to at least one segment of a first fiber strand of the plurality of optical fiber strands. Each node is sequentially disposed at respective locations along the first fiber strand at different differences from the optical hub, respectively. The network further includes a plurality of end-points. Each end-point includes a receiver. Each respective receiver (i) has a different optical signal-to-noise ratio (OSNR) from the other receivers, (ii) is operably coupled with at least one node of the plurality of nodes, and (iii) is configured to receive the same optical wavelength signal from the first fiber strand as received by the other receivers.

Abstract: A full duplex communication network includes an optical transmitter end having a first coherent optics transceiver, an optical receiver end having a second coherent optics transceiver, and an optical transport medium operably coupling the first coherent optics transceiver to the second coherent optics transceiver. The first coherent optics transceiver is configured to (i) transmit a downstream optical signal at a first wavelength, and (ii) simultaneously receive an upstream optical signal at a second wavelength. The second coherent optics transceiver is configured to (i) receive the downstream optical signal, and (ii) simultaneously transmit the upstream optical signal. The first wavelength has a first center frequency separated from a second center frequency of the second wavelength.

Abstract: An optical full-field transmitter for an optical communications network includes a primary laser source configured to provide a narrow spectral linewidth for a primary laser signal, and a first intensity modulator in communication with a first amplitude data source. The first intensity modulator is configured to output a first amplitude-modulated optical signal from the laser signal. The transmitter further includes a first phase modulator in communication with a first phase data source and the first amplitude-modulated optical signal. The first phase modulator is configured to output a first two-stage full-field optical signal. The primary laser source has a structure based on a III-V compound semiconductor.

Abstract: A communication network includes a coherent optics transmitter, a coherent optics receiver, an optical transport medium operably coupling the coherent optics transmitter to the coherent optics receiver, and a coherent optics interface. The coherent optics interface includes a lineside interface portion, a clientside interface portion, and a control interface portion.

Abstract: A coherent optical transmitter is in operable communication with an optical fiber an includes a plurality of analog-to-digital converters (ADCs) configured to (i) receive a plurality of radio frequency analog input signals, respectively, and (ii) convert the received plurality of RF analog input signals into a plurality of respective digital data streams. The transmitter further includes a source laser configured to output at least two orthogonal polarization component signals, and at least two polarization modulators configured to modulate (i) an in-phase portion output from a first ADC, (ii) an in-quadrature portion output from a second ADC, and (iii) one polarization component signal of the at least two orthogonal polarization component signals. The transmitter further includes a polarization beam combiner configured to (i) multiplex the respective outputs of the at least two polarization modulators, and (ii) transmit the multiplexed output from the polarization beam combiner to the optical fiber.

Abstract: A digital mobile fronthaul (MFH) network includes a baseband processing unit (BBU) having a digitization interface configured to digitize, using delta-sigma digitization, at least one wireless service for at least one radio access technology. The network further includes a transport medium in operable communication with the BBU. The transport medium is configured to transmit a delta-sigma digitized wireless service from the BBU. The network further includes a remote radio head (RRH) configured to operably receive the delta-sigma digitized wireless service from the BBU over the transport medium.

Abstract: An injection locked transmitter for an optical communication network includes a master seed laser source input substantially confined to a single longitudinal mode, an input data stream, and a laser injected modulator including at least one slave laser having a resonator frequency that is injection locked to a frequency of the single longitudinal mode of the master seed laser source. The laser injected modulator is configured to receive the master seed laser source input and the input data stream, and output a laser modulated data stream.

Abstract: An optical network communication system utilizes a passive optical network including an optical hub having an optical line terminal, downstream transmitter, an upstream receiver, a processor, and a multiplexer. The upstream receiver includes a plurality of TWDMA upstream subreceivers. The system includes a power splitter for dividing a coherent optical signal from the optical hub into a plurality of downstream wavelength signals, a long fiber to carry the coherent optical signal between the optical hub and the power splitter, and a plurality of serving groups. Each serving group includes a plurality of optical network units configured to (i) receive at least one downstream wavelength signal, and (ii) transmit at least one upstream wavelength signal. The system includes a plurality of short fibers to carry the downstream and upstream wavelength signals between the power splitter and the optical network units, respectively. Each upstream subreceiver receives a respective upstream wavelength signal.

Abstract: A method for implementing an out-of-band communication channel in a coherent optical access network includes steps (a)-(e). Step (a) includes separating a MAC-layer signal received from a media access control (MAC) layer into an initial communication-channel signal and an initial data-channel signal. Step (b) includes encoding, using a first signal-coding scheme within a transceiver of a coherent passive optical network (PON), the initial communication-channel signal into a communication-channel signal occupying a first frequency band. Step (c) includes encoding, using a second signal-coding scheme within the transceiver, the initial data-channel signal into a data-channel signal occupying a second frequency band not overlapping the first frequency band. Step (d) includes combining the communication-channel signal and the data-channel signal to yield an analog signal.

Abstract: An optical network includes a transmitting portion configured to (i) encode an input digitized sequence of data samples into a quantized sequence of data samples having a first number of digits per sample, (ii) map the quantized sequence of data samples into a compressed sequence of data samples having a second number of digits per sample, the second number being lower than the first number, and (iii) modulate the compressed sequence of data samples and transmit the modulated sequence over a digital optical link. The optical network further includes a receiving portion configured to (i) receive and demodulate the modulated sequence from the digital optical link, (ii) map the demodulated sequence from the second number of digits per sample into a decompressed sequence having the first number of digits per sample, and (iii) decode the decompressed sequence.

Abstract: A carrier-phase recovery method includes: (i) applying a first carrier-phase recovery algorithm to complex-valued symbols of a signal received by a product detector, yielding coarse phase-estimates, the signal being modulated per an M-QAM scheme; (ii) modelling the coarse phase-estimates as a weighted sum of M probability-density functions of an M-component mixture model; (iii) optimizing the M probability-density functions with an expectation-maximization algorithm to yield M optimized probability-density functions; (iv) mapping, based on the M optimized probability-density functions, the coarse phase-estimates to one of M symbols corresponding to the QAM scheme, each coarse phase-estimate mapped to a same symbol belonging to a same one of M clusters; (v) applying a second carrier-phase recovery algorithm to each of the M clusters to generate refined phase-estimates each corresponding to a respective coarse phase-estimate; and (vi) mapping, based on the M optimized probability-density functions, each refined

Abstract: An optical network includes a transmitter portion configured to transmit a digitized stream of symbols over a digital optical link, a mapping unit disposed within the transmitter portion and configured to code the transmitted digitized stream of symbols with a mapping code prior to transmission over the digital optical link, a receiver portion configured to recover the coded stream of symbols from the digital optical link, and a demapping unit disposed within the receiver portion and configured to map the recovered coded stream of symbols into an uncoded digitized signal corresponding to the digitized stream of symbols at the transmitter portion prior to coding by the mapping unit.

Abstract: Generating an assessment of the suitability of cables, ducts, tubes, pipes and/or other hollow-type of conduits to extraction of cores, conductors, insulation, etc. included therein while still buried in the ground or otherwise positioned out-of-sight so as to be unavailable for visual and/or physical inspection is contemplated. The assessment may be used to indicate a suitability of a cable buried in the ground of a hybrid fiber coaxial (HFC) cable plant to extraction of the type whereby a core of the cable may be extracted using hydraulics while still buried.

Abstract: An optical access network includes an optical hub having at least one processor. The network further includes a plurality of optical distribution centers connected to the optical hub by a plurality of optical fiber segments, respectively, and a plurality of geographic fiber node serving areas. Each fiber node serving area of the plurality of fiber node serving areas includes at least one optical distribution center of the plurality of optical distribution centers. The network further includes a plurality of endpoints. Each endpoint of the plurality of endpoints is in operable communication with at least one optical distribution center. The network further includes a point-to-point network provisioning system configured to (i) evaluate each potential communication path over the plurality of optical fiber segments between a first endpoint and a second endpoint, and (ii) select an optimum fiber path based on predetermined path selection criteria.

Abstract: An optical network communication system includes an optical hub, an optical distribution center, at least one fiber segment, and at least two end users. The optical hub includes an intelligent configuration unit configured to monitor and multiplex at least two different optical signals into a single multiplexed heterogeneous signal. The optical distribution center is configured to individually separate the at least two different optical signals from the multiplexed heterogeneous signal. The at least one fiber segment connects the optical hub and the optical distribution center, and is configured to receive the multiplexed heterogeneous signal from the optical hub and distribute the multiplexed heterogeneous signal to the optical distribution center. The at least two end users each include a downstream receiver configured to receive one of the respective separated optical signals from the optical distribution center.

Abstract: A resource allocation method is provided for a non-orthogonal multiple access distribution of access network users communicatively coupled to a single transport medium. The method includes steps of allocating a first frequency and time domain resource to a first user and a second frequency and time domain resource to a second user of the access network users, obtaining channel information regarding a particular communication channel of the access network for which resources are allocated, grouping the first user with the second user based on an overlap of the first frequency and time domain resource with the second frequency and time domain resource, and assigning the first user to a different power allocation resource than the second user within the frequency and time domain overlap.