Abstract: Multi-data stream and multi-beam beamforming in a wireless communications system (WCS) is disclosed. In the WCS, a wireless node(s) is configured to simultaneously emit multiple radio frequency (RF) beams in multiple intended directions. In this regard, in embodiments disclosed herein, the wireless node(s) is configured to include a beamforming circuit(s), which is configured to process multiple data streams to generate multiple processed streams each bearing the multiple data streams, and an antenna array(s) configured to simultaneously radiate the multiple processed streams to thereby form the multiple RF beams. Specifically, the beamforming circuit(s) is configured to generate each of the processed streams with predefined phase and amplitude to thereby cause the RF beams to be simultaneously formed in multiple elevations and/or azimuth angles.

Abstract: Reducing beamforming power consumption in a wireless communications system (WCS) is disclosed. In the WCS, a wireless node(s) is configured to emit a data-bearing radio frequency (RF) beam(s) in an intended direction(s). Specifically, the wireless node(s) is configured to form the data-bearing RF beam(s) by preprocessing a data signal based on a beamforming codeword to generate multiple beamforming signals, amplifying the beamforming signals to certain output powers using multiple power amplifiers, and emitting the amplified beamforming signals simultaneously from multiple antenna elements. In embodiments disclosed herein, the wireless node(s) can be configured to suppress a sidelobe(s) associated with the data-bearing RF beam(s) without sacrificing efficiency and/or increasing power consumption of the power amplifiers.

Abstract: Reducing an uplink accumulated noise floor in a distributed communications system (DCS) is disclosed. The DCS includes a number of remote units that communicate a number of uplink digital communications signals to a base station concurrently. In DCSs disclosed in certain aspects herein, a signal source, such as a digital baseband unit (BBU) for example, includes multiple receiver circuits each configured to receive and decode a respective one of the uplink digital communications signals. By individually receiving and decoding the uplink digital communications signals before combining the uplink digital communications signals, each of the receiver circuits can operate with a lowered noise floor. As a result, it is possible to improve received sensitivity of the receiver circuits, thus helping to improve coverage range, spectrum efficiency, and data throughput of the DCS.

Abstract: Reducing an uplink accumulated noise floor in a distributed communications system (DCS) is disclosed. The DCS includes a number of remote units that communicate a number of uplink digital communications signals to a base station concurrently. In DCSs disclosed in certain aspects herein, a signal source, such as a digital baseband unit (BBU) for example, includes multiple receiver circuits each configured to receive and decode a respective one of the uplink digital communications signals. By individually receiving and decoding the uplink digital communications signals before combining the uplink digital communications signals, each of the receiver circuits can operate with a lowered noise floor. As a result, it is possible to improve received sensitivity of the receiver circuits, thus helping to improve coverage range, spectrum efficiency, and data throughput of the DCS.

Abstract: Embodiments of the disclosure relate to selective multichannel amplification in a distributed communication system. In this regard, a remote antenna unit (RAU) in the distributed communication system receives downlink digital signals associated with downlink channels having respective downlink channel bandwidths. The RAU digitally scales the downlink digital signals based on respective digital scaling factors to generate scaled downlink digital signals having a substantially equal channel power density in the downlink channels. By digitally scaling the downlink digital signals to provide the substantially equal channel power density in the downlink channels, it is possible to provide substantially uniform radio frequency (RF) coverage range across the downlink channels, thus helping to improve overall RF coverage and user experience in a coverage area of the distributed communication system.

Abstract: Embodiments of the disclosure relate to selective multichannel amplification in a distributed communication system. In this regard, a remote antenna unit (RAU) in the distributed communication system receives downlink digital signals associated with downlink channels having respective downlink channel bandwidths. The RAU digitally scales the downlink digital signals based on respective digital scaling factors to generate scaled downlink digital signals having a substantially equal channel power density in the downlink channels. By digitally scaling the downlink digital signals to provide the substantially equal channel power density in the downlink channels, it is possible to provide substantially uniform radio frequency (RF) coverage range across the downlink channels, thus helping to improve overall RF coverage and user experience in a coverage area of the distributed communication system.

Abstract: Monitoring non-supported wireless spectrum within a coverage area of a distributed antenna system (DAS) in which a listening module connected to a remote unit of the DAS monitors non-supported wireless frequencies (i.e., frequencies that are outside the frequency ranges supported by the downlink and uplink signals of the DAS), via one or more antennas. The listening module also transmits the wireless frequencies to a monitoring module connected to head-end equipment (HEE) of the DAS. In that manner, a monitoring module can use an existing DAS infrastructure to monitor non-supported portions of the wireless spectrum at remote locations. In addition to avoiding the need to run a parallel DAS infrastructure, the disclosed arrangements are also useful in shared spectrum environments and other environments where efficient spectrum utilization is desired.

Abstract: Embodiments of the disclosure relate to selective multichannel amplification in a distributed communication system. In this regard, a remote antenna unit (RAU) in the distributed communication system receives downlink digital signals associated with downlink channels having respective downlink channel bandwidths. The RAU digitally scales the downlink digital signals based on respective digital scaling factors to generate scaled downlink digital signals having a substantially equal channel power density in the downlink channels. By digitally scaling the downlink digital signals to provide the substantially equal channel power density in the downlink channels, it is possible to provide substantially uniform radio frequency (RF) coverage range across the downlink channels, thus helping to improve overall RF coverage and user experience in a coverage area of the distributed communication system.

Abstract: Embodiments of the disclosure relate to reducing out-of-channel noise in a wireless distribution system (WDS). A digital filter in a remote unit is configured to suppress out-of-channel noise in a downlink digital communications signal based on at least one filter configuration parameter received from a control circuit. The control circuit is configured to determine the filter configuration parameter based on physical characteristics of the downlink digital communications signal. By suppressing the out-of-channel noise of the downlink digital communications signal, it is possible to provide a downlink RF communications signal communicated from the remote unit that complies with a spectrum emission mask (SEM).

Abstract: Embodiments of the disclosure relate to reducing out-of-channel noise in a wireless distribution system (WDS). A digital filter in a remote unit is configured to suppress out-of-channel noise in a downlink digital communications signal based on at least one filter configuration parameter received from a control circuit. The control circuit is configured to determine the filter configuration parameter based on physical characteristics of the downlink digital communications signal. By suppressing the out-of-channel noise of the downlink digital communications signal, it is possible to provide a downlink RF communications signal communicated from the remote unit that complies with a spectrum emission mask (SEM).

Abstract: Methods and systems for reducing leaked downlink interference signals in a remote unit uplink path(s) in a distributed antenna system (DAS) are provided. In a remote antenna unit (RAU) disclosed herein, a downlink interference signal may be leaked from a downlink path to an uplink path in the RAU. In this regard, an adjustment circuit is provided in the downlink path of the RAU to suppress the downlink interference signal. A control system is provided in the DAS to monitor the leaked downlink interference signal and control the adjustment circuit in the RAU to minimize the leaked downlink interference signal in the uplink path. By providing the adjustment circuit in the RAU and the control system in the DAS to minimize the leaked downlink interference signal in the uplink path, it is possible to reduce interferences between downlink and uplink communications signals without increasing costs of the RAU.

Abstract: One embodiment of the disclosure relates to supporting distinct single-input single-output (SISO) services in a multiple-input multiple-output (MIMO) baseband circuit, particularly suited for a distributed antenna system (DAS). In this regard, in one aspect, two communication paths in the MIMO baseband circuit are reconfigured to distribute two distinct SISO signals. A quadrature modulator modulates the two distinct SISO signals to two different radio frequency (RF) bands, respectively, based on a modulation frequency. In another aspect, the two or more distinct SISO signals are provided to the quadrature modulator using two intermediate frequencies (IFs) that are determined based on the center frequencies and bandwidths of the two different RF bands. By reconfiguring the MIMO baseband circuit to distribute the two distinct SISO signals, it is possible to retro-support new wireless communication services and/or new RF bands in existing DAS installations without replacing the MIMO baseband circuit.

Abstract: Embodiments of the disclosure relate to determining actual loop gain in a distributed antenna system (DAS). In this regard, a test signal(s) having a first power level is injected into a DAS from a first contact point. The test signal(s) is configured to propagate from the first contact point to a second contact point over a downlink path and an uplink path, thus creating a signal loop(s). A second power level of the test signal(s) is measured at the second contact point, and an actual loop gain of the DAS is determined by subtracting the first power level from the second power level. By determining the actual loop gain of the DAS, it is possible to further determine a gain margin of the DAS. Based on the gain margin, it is possible to determine optimization possibilities for the DAS to maximize capacity and performance of the DAS.

Abstract: Optimizing ripple reductions in equalizers shared between multiple interface ports in a distributed antenna system (DAS). In one aspect, a downlink equalizer is shared between a downlink simplex port and a duplex port in a radio interface module(s) (RIM(s)) in the DAS. In another aspect, to optimize ripple reduction in the downlink equalizer, the downlink equalizer is configured to go through a plurality of downlink equalizer states that each can generate a downlink equalizer frequency response affecting downlink ripple of the RIM(s). At each of the downlink equalizer states, a test signal is provided to the downlink equalizer and a corresponding downlink ripple of the RIM(s) is recorded. When all of the downlink equalizer states are evaluated based on the test signal, the downlink equalizer is configured to function based on the downlink equalizer state associated with the smallest downlink ripple of the RIM(s).

Abstract: Monitoring non-supported wireless spectrum within a coverage area of a distributed antenna system (DAS) in which a listening module connected to a remote unit of the DAS monitors non-supported wireless frequencies (i.e., frequencies that are outside the frequency ranges supported by the downlink and uplink signals of the DAS), via one or more antennas. The listening module also transmits the wireless frequencies to a monitoring module connected to head-end equipment (HEE) of the DAS. In that manner, a monitoring module can use an existing DAS infrastructure to monitor non-supported portions of the wireless spectrum at remote locations. In addition to avoiding the need to run a parallel DAS infrastructure, the disclosed arrangements are also useful in shared spectrum environments and other environments where efficient spectrum utilization is desired.

Abstract: Apparatus for dissipating shock-wave energy experienced by a test model having a base and being supported at a first location by a sting in a wind tunnel comprising apparatus movably mounted onto the sting for locking thereto at a second location the base portion of the test model and apparatus for selectably moving said apparatus for locking into and out of locking engagement with the test model and the sting.