摘要:
The invention is directed to a method and system for supporting MIMO technologies which can require the transport of multiple spatial streams on a traditional Distributed Antenna System (DAS). According to the invention, at one end of the DAS, each spatial stream is shifted in frequency to a pre-assigned band (such as a band at a frequency lower than the native frequency) that does not overlap the band assigned to other spatial streams (or the band of any other services being carried by the DAS). Each of the spatial streams can be combined and transmitted as a combined signal over a common coaxial cable. At the other “end” of the DAS, the different streams are shifted back to their original (overlapping) frequencies but retain their individual “identities” by being radiated through physically separate antenna elements.
摘要:
Systems, devices and methods enabling appearance comparison. The system includes at least one interactive imaging and display station. The station includes a mirror-display device capable of selectably operating in either or both a mirror mode or a display mode; an imaging device to capture one or more appearances appearing in a field of view in front of the mirror-display device; and/or an image control unit to select the mode of operation of the mirror-display device according to a user command.
摘要:
A system for supporting multiple time division duplexed (TDD) based wireless services or frequency division duplexed (FDD) wireless services on a Distributed Antenna System (DAS). TDD based services use a common clock signal to synchronize the components of the DAS for transmission and reception of TDD signals. The DAS includes a GPS receiver which extracts a timing signal from a GPS signal and distribute the timing signal to components of the DAS to enable synchronization of the components for transmitting and receiving TDD signals. The GPS receiver can be part of the interface that connects a TDD based service to the DAS. The DAS distributes a reference clock signal to the DAS components to maintain zero frequency shift while manipulating with the carrier frequencies of the various wireless services carried by the DAS.
摘要:
A method and system suitable for supporting wireless medical telemetry services (MTS) on a Distributed Antenna System (DAS). A DAS can provide wireless services including voice and data services using the same equipment. WMTS systems can include one or more active antenna units controlled by the MTS access point. The DAS includes control channels for transferring the MTS control and status information between the MTS access point and the antenna. The control channels can be transferred over a separate cable, or transferred using one or more intermediate frequency signals transferred over existing cables DAS between the MTS access point and the antenna. The control channels can be used to configure and control and receive status from the managed components of the DAS including active antennas, control the amplifiers used to process TDD signals, and control the switching of the diversity antenna systems.
摘要:
A system and method for ensuring proper synchronization of a plurality of frequency sources used in reception diversity-based radio reception. The frequency sources are concatenated in a synchronization loop, through which one frequency source having a high performance oscillator is configured as a master source. Through its oscillator, the master provides an internal synchronization signal that synchronizes all other sources, which have lower performance oscillators and are configured as slaves. Upon a failure in the master oscillator or in the synchronization loop, a slave source takes over as an alternative master source and provides its internal oscillator signal as an alternative synchronization signal to all other frequency sources.
摘要:
The invention is directed to a method and system for supporting multiple time division duplexed (TDD) based wireless services or frequency division duplexed (FDD) wireless services on a Distributed Antenna System (DAS). A DAS can support a many wireless services, including voice and data services using the same physical equipment. TDD based services use a common clock signal to synchronize the components of the DAS for transmission and reception of TDD signals. In accordance with the invention, the DAS can include a GPS receiver which can extract a timing signal (such as a 1 pps signal) from a GPS signal and distribute the timing signal to any and all components of the DAS to enable synchronization of the components for transmitting and receiving TDD signals. The GPS receiver can be part of the interface that connects a TDD based service to the DAS or separate component of the DAS. In accordance with the invention, the DAS can distribute a reference clock signal to all of the components of the DAS in order to maintain zero frequency shift while manipulating with the carrier frequencies of the various wireless services carried by the DAS. In addition, and in accordance with the invention, two analog architectures for better integration between the services sources (BTS) and the DAS are disclosed.
摘要:
A tentative location of a transmitter in an indoor environment is determined by triangulation, using at least two direction finders. The tentative location is made more accurate by performing at least one added action selected from the following: checking the likelihood that the tentative location is an accurate location by comparing measured transmitter signal strengths with calculated signal strengths, using a known indoor environment structure, using a record of the transmitter movement through the indoor environment for determining whether the transmitter is located in an obscured area of the indoor environment or performing an alignment procedure on the antennas to improve the triangulation.
摘要:
The present invention is directed to improvements for distributed antenna systems and more particularly to methods and systems for improving uplink communications. In one embodiment, Aggregation Point Noise Blocking provides for blocking or filtering the noise contributed by one or more of the branches coupled to an aggregation point that are not carrying the signal from a particular terminal. Signal activity from a given terminal on a particular branch can be identified and that information can be used to selectively block or filter the signal noise contributed by the other branches to an aggregation point. The selective blocking or filtering can also include an attenuation function to attenuate the signal and provide dynamic range smoothing. In another embodiment the signal can be regenerated to produce a signal that has a restored or very high SNR. An uplink regeneration block can be provided which demodulates the uplink signal to recover the transmitted information and then re-modulates the transmitted information to regenerate a signal at a restored or very high SNR.
摘要:
The present invention is directed to improvements for distributed antenna systems and more particularly to methods and systems for improving uplink communications. In one embodiment, Aggregation Point Noise Blocking provides for blocking or filtering the noise contributed by one or more of the branches coupled to an aggregation point that are not carrying the signal from a particular terminal. Signal activity from a given terminal on a particular branch can be identified and that information can be used to selectively block or filter the signal noise contributed by the other branches to an aggregation point. The selective blocking or filtering can also include an attenuation function to attenuate the signal and provide dynamic range smoothing. In another embodiment the signal can be regenerated to produce a signal that has a restored or very high SNR. An uplink regeneration block can be provided which demodulates the uplink signal to recover the transmitted information and then re-modulates the transmitted information to regenerate a signal at a restored or very high SNR.
摘要:
Spatially located ultrasound beacons are provided in known locations within a distributed communication system. The ultrasound beacons are configured to emit ultrasound pulses that can be received by client devices in ultrasound communication range of the beacons. The client devices are configured to analyze the received ultrasound pulses from the beacons to determine their time-difference of arrival and as a result, their location(s) within the distributed communication system. The client devices comprise inertial navigation systems (INS) that calculate client device location as the client device moves, and when received ultrasound signals are below a predefined threshold.