Abstract: A method of operating a communications system includes receiving a signal at a digital predistorter (DPD), introducing predistortion to the signal using the DPD, and converting the predistorted signal to an analog signal using a digital-to-analog converter having a first bandwidth. The method also includes amplifying the analog signal, sampling the amplified signal using an analog-to-digital converter having a second bandwidth less than the first bandwidth, and extracting coefficients of the DPD from the sampled signal.

Abstract: A system for routing signals in a Distributed Antenna System (DAS) includes one or more local Digital Access Units (DAUs) located at a local location and one or more remote DAUs located at one or more remote locations. Each of the one or more local DAUs includes an optical port coupled to an upstream unit. The upstream unit includes at least one of a repeater, a baseband unit, a Base Transceiver Station (BTS), or a DAU. The one or more remote DAUs are coupled to the one or more local DAUs via one or more optical cables. A distance between the local location and each of the one or more remote locations is greater than two kilometers.

Abstract: A digital predistortion linearization method is provided for increasing the instantaneous or operational bandwidth for RF power amplifiers employed in wideband communication systems. Embodiments of the present invention provide a method of increasing DPD linearization bandwidth using a feedback filter integrated into existing digital platforms for multi-channel wideband wireless transmitters. An embodiment of the present invention utilizes a DPD feedback signal in conjunction with a low power band-pass filter in the DPD feedback path.

Abstract: A system for data transport in a Distributed Antenna System (DAS) includes a plurality of remote Digital Access Units (DAUs) located at a Remote location. The plurality of remote DAUs are coupled to each other and operable to transport digital signals between the plurality of remote DAUs. The system also includes a plurality of central hubs. Each of the plurality of central hubs is in communication with one of the remote DAUs using an electrical communications path. The system further includes a plurality of transmit/receive cells. Each of the plurality of transmit/receive cells includes a plurality of remote hubs. Each of the remote hubs in one of the plurality of transmit/receive cells is in communication with one of the plurality of central hubs using an optical communications path.

Abstract: A system for indoor localization using satellite navigation signals in a Distributed Antenna System includes a plurality of Off-Air Access Units (OAAUs). Each of the plurality of OAAUs is operable to receive an individual satellite navigation signal from at least one of a plurality of satellites and operable to route signals optically to one or more DAUs. The system also includes a plurality of remote DRUs located at a Remote location. The plurality of remote DRUs are operable to receive signals from a plurality of the one or more DAUs. The system further includes an algorithm to delay each individual satellite navigation signal for providing indoor localization at each of the plurality of DRUs.

Abstract: A remote radio head. unit (RRU) system for multiple operating frequency bands, multi-channels, driven by a single or more wide band power amplifiers. More specifically, the present invention enables multiple-bands RRU to use fewer power amplifiers in order to reduce size and cost of the multi-band RRU. The present invention is based on the method of using duplexers and/or interference cancellation system technique to increase the isolation between the transmitter signal and receiver signal of the RRU.

Abstract: A system for indoor localization using satellite navigation signals in a Distributed Antenna System. The system includes a plurality of Off-Air Access Units (OAAUs), each operable to receive an individual satellite navigation signal from at least one of a plurality of satellite navigation systems (e.g., GPS, GLONASS, Galileo, QZSS, or BeiDou) and operable to route signals optically to one or more DAUs. The system further includes a plurality of remote DRUs located at a Remote location that are operable to receive signals from a plurality of local DAUs. Moreover, the system includes an algorithm to delay each individual satellite navigation signal for providing indoor localization at each of the plurality of DRUs.

Abstract: A method for routing and switching operator RF signals includes providing one or more Digital Remote Units (DRUs) and providing at least one Digital Access Unit (DAU) configured to communicate with at least one of the one or more DRUs. A first DRU is operable to communicate using a first set of frequencies characterized by a first frequency band over a first geographic footprint and a second set of frequencies characterized by a second frequency band different from the first frequency band over a second geographic footprint including and surrounding the first geographic footprint. A second DRU is operable to communicate using the first set of frequencies over a third geographical footprint and a third set of frequencies characterized by a third frequency band different from the first frequency band and the second frequency band over a fourth geographic footprint including and surrounding the third geographic footprint.

Abstract: A remote radio head unit (RRU) system is disclosed. The present invention is based on the method of adaptive digital predistortion to linearize a power amplifier inside the RRU. The power amplifier characteristics such as variation of linearity and asymmetric distortion of the amplifier output signal are monitored by a wideband feedback path and controlled by the adaptation algorithm in a digital module. Therefore, embodiments of the present invention can compensate for the nonlinearities as well as memory effects of the power amplifier systems and also improve performance, in terms of power added efficiency, adjacent channel leakage ratio and peak-to-average power ratio. The present disclosure enables a power amplifier system to be field reconfigurable and support multi-modulation schemes (modulation agnostic), multi-carriers, multi-frequency bands and multi-channels.

Abstract: A mesh network includes one or more digital access units (DAUs) operable to receive signals from a base transceiver station (BTS). The mesh network also includes a first digital remote unit (DRU) coupled to at least one of the one or more DAUs and a second digital remote unit (DRU) coupled to at least one of the one or more DAUs. The first DRU and the second DRU are coupled to each other through a wireless link.

Abstract: A system for data transport in a Distributed Antenna System (DAS) includes a plurality of remote Digital Access Units (DAUs) located at a Remote location. The plurality of remote DAUs are coupled to each other and operable to transport digital signals between the plurality of remote DAUs. The system also includes a plurality of central hubs. Each of the plurality of central hubs is in communication with one of the remote DAUs using an electrical communications path. The system further includes a plurality of transmit/receive cells. Each of the plurality of transmit/receive cells includes a plurality of remote hubs. Each of the remote hubs in one of the plurality of transmit/receive cells is in communication with one of the plurality of central hubs using an optical communications path.

Abstract: A real-time locating system (RTLS) for localization using satellite navigation signals in a Distributed Antenna System includes Off-Air Access Units (OAAUs), each being operable to receive an individual satellite navigation signal from a satellite and to route signals optically to a digital access unit (DAU). Remote digital remote units (DRUs) are located at Remote locations and are operable to receive signals the DAUs. Each individual satellite navigation signal can be appropriately delayed (in a manner that accounts for a DRU's location). For each antenna, a separation distance between a mobile station and a DRU can be estimated based on a signal receipt time at the station. In combination, these distances can be used to estimate the mobile station's precise indoor position.

Abstract: A system for routing signals in a Distributed Antenna System (DAS) includes one or more local Digital Access Units (DAUs) located at a local location and one or more remote DAUs located at one or more remote locations. Each of the one or more local DAUs includes an optical port coupled to an upstream unit. The upstream unit includes at least one of a repeater, a baseband unit, a Base Transceiver Station (BTS), or a DAU. The one or more remote DAUs are coupled to the one or more local DAUs via one or more optical cables. A distance between the local location and each of the one or more remote locations is greater than two kilometers.

Abstract: A RF-digital hybrid mode power amplifier system for achieving high efficiency and high linearity in wideband communication systems is disclosed. The present invention is based on the method of adaptive digital predistortion to linearize a power amplifier in the RF domain. The present disclosure enables a power amplifier system to be field reconfigurable and support multi-modulation schemes (modulation agnostic), multi-carriers and multi-channels. As a result, the digital hybrid mode power amplifier system is particularly suitable for wireless transmission systems, such as base-stations, repeaters, and indoor signal coverage systems, where baseband I-Q signal information is not readily available.

Abstract: A method of detecting a synchronization switching pulse using a power detector in a time division duplexing (TDD) system includes receiving an input signal, detecting a power level associated with the input signal using a digital power meter, and determining a configuration associated with the input signal. The method also includes determining that a pulse width associated with the input signal is greater than a threshold, determining an offset associated with a special subframe configuration, and generating an estimated sync pulse. The method further includes forming a regenerated sync pulse, determining an error between the estimated sync pulse and the regenerated sync pulse, determining that the error is less than a threshold, and providing a lock detect.

Abstract: A system for transporting data in a Distributed Antenna System (DAS) includes at least one Digital Access Unit (DAU) and a plurality of Digital Remote Units (DRUs) coupled to the at least one DAU. The plurality of DRUs are operable to transport signals between the plurality of DRUs and the at least one DAU. The at least one DAU includes: a data transport coder comprising: a framer, an encoder, a scrambler, and a serializer and a data transport decoder comprising: a deserializer, a decoder, a descrambler, a frame synchronizer, and a deframer.

Abstract: A remote radio head unit (RRU) system for achieving high data rate communications in a Distributed Antenna System is disclosed. The Distributed Antenna System is configured as a Neutral Host enabling multiple operators to exist on one DAS system. The present disclosure enables a remote radio head unit to be field reconfigurable and support multi-modulation schemes (modulation-independent), multi-carriers, multi-frequency bands and multi-channels. As a result, the remote radio head system is particularly suitable for wireless transmission systems, such as base-stations, repeaters, and indoor signal coverage systems.

Abstract: Methods and apparatuses are presented for balancing non-uniformly distributed network traffic in a wireless communications system having a plurality of digital remote units (DRUs). In some embodiments, a method comprises partitioning the plurality of DRUs into a plurality of DRU sectors, and dynamically repartitioning the plurality of DRU sectors depending on traffic conditions in at least one of the DRU sectors, such that the repartitioning satisfies at least one of a soft capacity constraint or a hard capacity constraint. The dynamic repartitioning may be based on at least one optimization algorithm.

Abstract: A remote radio head. unit (RRU) system for multiple operating frequency bands, multi-channels, driven by a single or more wide band power amplifiers. More specifically, the present invention enables multiple-bands RRU to use fewer power amplifiers in order to reduce size and cost of the multi-band RRU. The present invention is based on the method of using duplexers and/or interference cancellation system technique to increase the isolation between the transmitter signal and receiver signal of the RRU.

Abstract: A system for indoor localization using satellite navigation signals in a Distributed Antenna System. The system includes a plurality of Off-Air Access Units (OAAUs), each operable to receive an individual satellite navigation signal from at least one of a plurality of satellite navigation systems (e.g., GPS, GLONASS, Galileo, QZSS, or BeiDou) and operable to route signals optically to one or more DAUs. The system further includes a plurality of remote DRUs located at a Remote location that are operable to receive signals from a plurality of local DAUs. Moreover, the system includes an algorithm to delay each individual satellite navigation signal for providing indoor localization at each of the plurality of DRUs.