Abstract: A system and method are described for distributed antenna wireless communications.

Abstract: Systems and methods are described to create radio daisy chains for convenient and aesthetically pleasing high-density radio deployments.

Abstract: Systems and methods are described to concurrently utilize actively used spectrum for new TDD or FDD networks, and also for enabling Distributed-Input Distributed Output (DIDO) techniques to be used with both the new networks and the existing networks in the same spectrum.

Abstract: An apparatus and method are described for capturing images in visible light as well as other radiation wavelengths. In one embodiment, the apparatus comprises: a diffraction coded imaging system including a plurality of apertures arranged in a diffraction coded array pattern with opaque material blocking array elements not containing apertures; and a light- or radiation-sensitive sensor coupled to the diffraction coded imaging system array and positioned at a specified distance behind the diffraction coded imaging system array, the radiation-sensitive sensor configured to sense light or radiation transmitted and diffracted through the apertures in the diffraction coded imaging system array.

Abstract: Systems and methods are described for radio frequency (RF) calibration in a multiple antenna system (MAS) with multi-user (MU) transmissions (“MU-MAS”) exploiting uplink/downlink channel reciprocity. The RF calibration is used to compute open-loop downlink precoder based on uplink channel estimates, thereby avoiding feedback overhead for channel state information as in closed-loop schemes. For example, a MU-MAS of one embodiment comprises a wireless cellular network with one or multiple beacon stations, multiple client devices and multiple distributed antennas operating cooperatively via precoding methods to eliminate inter-client interference and increase network capacity.

Abstract: A system and method are described which enable planned evolution and obsolescence of multiuser wireless spectrum. One embodiment of such a system includes one or multiple centralized processors and one or multiple distributed nodes that communicate via wireline or wireless connections. The distributed nodes may share their identification number and other reconfigurable system parameters with the centralized processor. The information about all distributed nodes may be stored in a database that is shared by all centralized processors. The reconfigurable system parameters may comprise power emission, frequency band, modulation/coding scheme. The distributed nodes may be software defined radios such as FPGA, DSP, GPU and/or GPCPU that run algorithms for baseband signal processing and may be reconfigured remotely by the centralized processor. A cloud wireless system may be used wherein the distributed nodes are reconfigured periodically or instantly to adjust to the evolving wireless architecture.

Abstract: Systems and methods are described to mitigate interference to out of band receivers using out of band training signals.

Abstract: A system and method are described for distributed antenna wireless communications.

Abstract: A system and machine-implemented method are described for communicating with a plurality of distributed-input-distributed-output (DIDO) clients.

Abstract: A multiple antenna system (MAS) with multiuser (MU) transmissions (“MU-MAS”) exploiting inter-cell multiplexing gain via spatial processing to increase capacity in wireless communications networks.

Abstract: Systems and methods are described for coordinating transmissions in distributed wireless systems via user clustering. For example, a method according to one embodiment of the invention comprises: measuring link quality between a target user and a plurality of distributed-input distributed-output (DIDO) distributed antennas of base transceiver stations (BTSs); using the link quality measurements to define a user cluster; measuring channel state information (CSI) between each user and each DIDO antenna within a defined user cluster; and precoding data transmissions between each DIDO antenna and each user within the user cluster based on the measured CSI.

Abstract: Systems and methods are described for enhancing the channel spatial diversity in a multiple antenna system (MAS) with multi-user (MU) transmissions (“MU-MAS”), by exploiting channel selectivity indicators. The proposed methods are: i) antenna selection; ii) user selection; iii) transmit power balancing. All three methods, or any combination of those, are shown to provide significant performance gains in DIDO systems in practical propagation scenarios.

Abstract: Systems and methods are described for radio frequency (RF) calibration in a multiple antenna system (MAS) with multi-user (MU) transmissions (“MU-MAS”) exploiting uplink/downlink channel reciprocity. The RF calibration is used to compute open-loop downlink precoder based on uplink channel estimates, thereby avoiding feedback overhead for channel state information as in closed-loop schemes. For example, a MU-MAS of one embodiment comprises a wireless cellular network with one or multiple beacon stations, multiple client devices and multiple distributed antennas operating cooperatively via precoding methods to eliminate inter-client interference and increase network capacity.

Abstract: An apparatus and method are described for capturing images in visible light as well as other radiation wavelengths. In one embodiment, the apparatus comprises: a diffraction coded imaging system including a plurality of apertures arranged in a diffraction coded array pattern with opaque material blocking array elements not containing apertures; and a light- or radiation-sensitive sensor coupled to the diffraction coded imaging system array and positioned at a specified distance behind the diffraction coded imaging system array, the radiation-sensitive sensor configured to sense light or radiation transmitted and diffracted through the apertures in the diffraction coded imaging system array.

Abstract: A system and method are described which enable planned evolution and obsolescence of multiuser wireless spectrum. One embodiment of such a system includes one or multiple centralized processors and one or multiple distributed nodes that communicate via wireline or wireless connections. The distributed nodes may share their identification number and other reconfigurable system parameters with the centralized processor. The information about all distributed nodes may be stored in a database that is shared by all centralized processors. The reconfigurable system parameters may comprise power emission, frequency band, modulation/coding scheme. The distributed nodes may be software defined radios such as FPGA, DSP, GPU and/or GPCPU that run algorithms for baseband signal processing and may be reconfigured remotely by the centralized processor. A cloud wireless system may be used wherein the distributed nodes are reconfigured periodically or instantly to adjust to the evolving wireless architecture.

Abstract: A system and methods are described which compensate for the adverse effect of Doppler on the performance of DIDO systems. One embodiment of such a system employs different selection algorithms to adaptively adjust the active BTSs to different UEs based by tracking the changing channel conditions. Another embodiment utilizes channel prediction to estimate the future CSI or DIDO precoding weights, thereby eliminating errors due to outdated CSI.

Abstract: A system and method are described for distributed antenna wireless communications.

Abstract: Systems and methods are described for coordinating transmissions in distributed wireless systems via user clustering. For example, a method according to one embodiment of the invention comprises: measuring link quality between a target user and a plurality of distributed-input distributed-output (DIDO) distributed antennas of base transceiver stations (BTSs); using the link quality measurements to define a user cluster; measuring channel state information (CSI) between each user and each DIDO antenna within a defined user cluster; and precoding data transmissions between each DIDO antenna and each user within the user cluster based on the measured CSI.

Abstract: Non-linear or linear precoding is used to create separate areas of coherence to different users. Limited feedback techniques may also be employed to send channel state information (CSI) from the plurality of users to the MU-MAS. In some embodiments, a codebook is built based on basis functions that span the radiated field of a transmit array. Additionally, the precoding may be continuously updated to create non-interfering areas of coherence to the users as the wireless channel changes due to Doppler effect. Moreover, the size of the areas of coherence may be dynamically adjusted depending on the distribution of users.

Abstract: Systems and methods are described for enhancing the channel spatial diversity in a multiple antenna system (MAS) with multi-user (MU) transmissions (“MU-MAS”), by exploiting channel selectivity indicators. The proposed methods are: i) antenna selection; ii) user selection; iii) transmit power balancing. All three methods, or any combination of those, are shown to provide significant performance gains in DIDO systems in practical propagation scenarios.