Patents Assigned to Dali Systems Co. Ltd.
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Patent number: 11818808Abstract: One exemplary aspect generally relates to public safety communication systems employing Distributed Antenna Systems (DAS) and/or a Digital Distribution System (DDS) as part of a distributed wireless network. More specifically, one aspect relates to a DAS/DDS architecture utilizing a software (re)configurable network. Even more specifically, one aspect relates to a DAS/DDS architecture having a redundant system topology as well as failover capabilities at one or more of the hardware/software level and/or the communication link level.Type: GrantFiled: January 29, 2021Date of Patent: November 14, 2023Assignee: Dali Systems Co. Ltd.Inventors: Sasa Trajkovic, Andrew Leung
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Patent number: 11394350Abstract: A system for time aligning widely frequency spaced signals includes a digital predistortion (DPD) processor and a power amplifier coupled to the DPD processor and operable to provide a transmit signal at a power amplifier output. The system also includes a feedback loop coupled to the power amplifier output. The feedback loop comprises an adaptive fractional delay filter, a delay estimator coupled to the adaptive fractional delay filter, and a DPD coefficient estimator coupled to the delay estimator.Type: GrantFiled: March 13, 2019Date of Patent: July 19, 2022Assignee: Dali Systems Co. Ltd.Inventor: Wan Jong Kim
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Patent number: 11381312Abstract: A redundancy system for data transport in a Distributed Antenna System (DAS) includes a plurality of Digital Access Units (DAUs). Each of the plurality of DAUs is fed by a plurality of data streams and is operable to transport digital signals between others of the plurality of DAUs. The redundancy system also includes a plurality of Digital Distribution Units (DDUs). Each of the plurality of DDUs is in communication with each of the plurality of DAUs using cross connection communication paths. The redundancy system further includes a plurality of Digital Remote Units (DRUs). Each of the plurality of DRUs is in communication with each of the plurality of DDUs using cross connection communications paths.Type: GrantFiled: May 24, 2021Date of Patent: July 5, 2022Assignee: Dali Systems Co. Ltd.Inventors: Sasa Trajkovic, Andrew Leung
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Patent number: 11095326Abstract: 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.Type: GrantFiled: July 7, 2020Date of Patent: August 17, 2021Assignee: DALI SYSTEMS CO. LTD.Inventors: Wan-Jong Kim, Shawn Patrick Stapleton
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Patent number: 11057109Abstract: A method for operating a Distributed Antenna System (DAS) includes providing a plurality of Digital Remote Units (DRUs), each configured to send and receive wireless radio signals and providing a plurality of inter-connected Digital Access Units (DAUs), each configured to communicate with at least one of the plurality of DRUs via optical signals and each being coupled to at least one sector of a base station. The method also includes providing a plurality of sensors operable to detect activity at each of the plurality of DRUs, turning off a DRU downlink signal at one of the plurality of DRUs in response to an output from one of the plurality of sensors, and turning on a DRU downlink signal at another of the plurality of DRUs in response to an output from another of the plurality of sensors.Type: GrantFiled: March 21, 2019Date of Patent: July 6, 2021Assignee: DALI SYSTEMS CO. LTD.Inventors: Shawn Patrick Stapleton, Sasa Trajkovic, Wolfgang Weber
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Patent number: 11026077Abstract: The present disclosure generally relates to wireless communication systems employing Distributed Antenna Systems (DAS) as part of a distributed wireless network. More specifically, the present disclosure relates to a DAS network that utilizes traffic monitoring of mobile devices of a distributed wireless network. Traffic monitoring may be used to monitor the DAS network performance and generate analytics of individual mobile devices.Type: GrantFiled: July 6, 2016Date of Patent: June 1, 2021Assignee: DALI SYSTEMS CO. LTD.Inventor: Shawn Patrick Stapleton
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Patent number: 11018769Abstract: A redundancy system for data transport in a Distributed Antenna System (DAS) includes a plurality of Digital Access Units (DAUs). Each of the plurality of DAUs is fed by a plurality of data streams and is operable to transport digital signals between others of the plurality of DAUs. The redundancy system also includes a plurality of Digital Distribution Units (DDUs). Each of the plurality of DDUs is in communication with each of the plurality of DAUs using cross connection communication paths. The redundancy system further includes a plurality of Digital Remote Units (DRUs). Each of the plurality of DRUs is in communication with each of the plurality of DDUs using cross connection communications paths.Type: GrantFiled: April 29, 2020Date of Patent: May 25, 2021Assignee: DALI SYSTEMS CO. LTD.Inventors: Sasa Trajkovic, Andrew Leung
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Patent number: 10931377Abstract: 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.Type: GrantFiled: January 9, 2020Date of Patent: February 23, 2021Assignee: DALI SYSTEMS CO. LTD.Inventors: Shawn Patrick Stapleton, Sasa Trajkovic
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Patent number: 10863470Abstract: 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.Type: GrantFiled: September 6, 2019Date of Patent: December 8, 2020Assignee: DALI SYSTEMS CO. LTD.Inventors: Wan-Jong Kim, Shawn Patrick Stapleton
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Patent number: 10749553Abstract: 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.Type: GrantFiled: February 19, 2019Date of Patent: August 18, 2020Assignee: DALI SYSTEMS CO. LTDInventors: Wan-Jong Kim, Shawn Patrick Stapleton
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Patent number: 10728066Abstract: 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.Type: GrantFiled: November 30, 2017Date of Patent: July 28, 2020Assignee: DALI SYSTEMS CO. LTD.Inventors: Wan Jong Kim, Kyoung Joon Cho, Shawn Patrick Stapleton, Ying Xiao
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Patent number: 10727879Abstract: 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.Type: GrantFiled: January 4, 2019Date of Patent: July 28, 2020Assignee: DALI SYSTEMS CO. LTD.Inventors: Wan-Jong Kim, Shawn Patrick Stapleton
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Patent number: 10721548Abstract: 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.Type: GrantFiled: July 18, 2018Date of Patent: July 21, 2020Assignee: DALI SYSTEMS CO. LTD.Inventors: Shawn Patrick Stapleton, Sasa Trajkovic
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Patent number: 10681563Abstract: A system for networking Wi-Fi Access Points in a Distributed Antenna System includes a plurality of Digital Access Units (DAUs). The plurality of DAUs are coupled and operable to route signals between the plurality of DAUs. The system also includes a plurality of Digital Remote Units (DRUs) coupled to the plurality of DAUs and operable to transport signals between DRUs and DAUs and a plurality of DAU ports and DRU ports. The system further includes a Framer/Deframer, wherein the cellular payload data is separated from the IP data and a network switch. The IP data from a plurality of DAU and DRU ports are buffered and routed to a plurality of DAU and DRU ports. Furthermore, the system includes a plurality of Wi-Fi access points coupled via a mesh network to Wi-Fi access points connected to a plurality of DRUs.Type: GrantFiled: February 27, 2018Date of Patent: June 9, 2020Assignee: DALI SYSTEMS CO. LTD.Inventors: Sasa Trajkovic, Shawn Patrick Stapleton, Qianqi Zhuang
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Publication number: 20200154288Abstract: A system for dynamically routing signals in a Distributed Antenna System includes a plurality of Digital Access Units (DAUs). The plurality of DAUs are coupled and operable to route signals between the plurality of DAUs. The system also includes a plurality of Digital Remote Units (DRUs) coupled to the plurality of DAUs and operable to transport signals between DRUs and DAUs and a plurality of Base Transceiver Stations (BTS). The system further includes a plurality of traffic monitoring modules and a network optimization goal and optimization algorithm.Type: ApplicationFiled: October 23, 2019Publication date: May 14, 2020Applicant: Dali Systems Co. Ltd.Inventors: Shawn Patrick Stapleton, Seyed Amin Hejazi
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Publication number: 20200145060Abstract: A system for transporting IP data in a Distributed Antenna System includes at least one Digital Access Units (DAU) having a plurality of optical input/output ports and at least one Ethernet port and a plurality of Digital Remote Units (DRUs) coupled to the at least one DAU. Each of the plurality of DRUs has a plurality of optical input/output ports and at least one Ethernet port. The at least one DAU includes a Framer/Deframer operable to separate cellular payload data from IP data and a network switch operable to buffer the cellular payload data and the IP data and to route the IP data received from the plurality of DRUs to the at least one Ethernet port of the DAU.Type: ApplicationFiled: July 17, 2019Publication date: May 7, 2020Applicant: Dali Systems Co. Ltd.Inventors: Qianqi Zhuang, Shawn Patrick Stapleton
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Patent number: 10644798Abstract: A redundancy system for data transport in a Distributed Antenna System (DAS) includes a plurality of Digital Access Units (DAUs). Each of the plurality of DAUs is fed by a plurality of data streams and is operable to transport digital signals between others of the plurality of DAUs. The redundancy system also includes a plurality of Digital Distribution Units (DDUs). Each of the plurality of DDUs is in communication with each of the plurality of DAUs using cross connection communication paths. The redundancy system further includes a plurality of Digital Remote Units (DRUs). Each of the plurality of DRUs is in communication with each of the plurality of DDUs using cross connection communications paths.Type: GrantFiled: May 12, 2017Date of Patent: May 5, 2020Assignee: DALI SYSTEMS CO. LTD.Inventors: Sasa Trajkovic, Andrew Leung
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Publication number: 20200137582Abstract: 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.Type: ApplicationFiled: May 28, 2019Publication date: April 30, 2020Applicant: Dali Systems Co. Ltd.Inventors: Seyed Amin Hejazi, Shawn Patrick Stapleton
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Publication number: 20200137709Abstract: 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.Type: ApplicationFiled: September 6, 2019Publication date: April 30, 2020Applicant: Dali Systems Co. Ltd.Inventors: Wan-Jong Kim, Shawn Patrick Stapleton
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Publication number: 20200136567Abstract: 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 power amplifier characteristics such as variation of linearity and asymmetric distortion of the amplifier output signal are monitored by the narrowband feedback path and controlled by the adaptation algorithm in a digital module. Therefore, the present invention could compensate the nonlinearities as well as memory effects of the power amplifier systems and also improve performances, 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 and multi-channels.Type: ApplicationFiled: October 3, 2019Publication date: April 30, 2020Applicant: Dali Systems Co. Ltd.Inventors: Wan Jong Kim, Kyoung Joon Cho, Shawn Patrick Stapleton, Jong Heon Kim, Dali Yang