摘要:
A communications device for separating source signals provided by M signal sources includes an antenna array comprising N antenna elements for receiving at least N different summations of the M source signals. A code despreader is connected to the N antenna elements for decoding the at least N different summations of the M source signals. Each one of the N different summations includes k codes for providing k different summations of the M source signals associated therewith. A blind signal separation processor forms a mixing matrix comprising at least kN different summations of the M source signals, and separates desired source signals from the mixing matrix. The mixing matrix has a rank equal up to kN.
摘要:
A communications device for separating source signals provided by M signal sources includes an antenna array comprising N correlated antenna elements for receiving at least N different summations of the M source signals, with N and M being greater than 1. A receiver is connected to the antenna array for receiving the at least N different summations of the M source signals. A blind signal separation processor is connected to the receiver for forming a mixing matrix comprising up to the at least N different summations of the M source signals, and for separating desired source signals from the mixing matrix. The mixing matrix has a rank equal to at least N.
摘要:
The present Broadband Link System supplements the existing Air-To-Ground Radio Frequency communications link with an additional, separate high speed Broadband Ground-To-Air Data Channel to provide additional data communication capacity for aircraft. This Broadband Ground-To-Air Data Channel is typically a uni-directional (Ground-To-Air) link directed via a focused beam to selected aircraft which are operational in the coverage area of the Broadband Ground-To-Air Data Channel. The routing of the various data transmissions on both the Air-To-Ground Radio Frequency communications link and the Broadband Ground-To-Air Data Channel are managed in a unified manner to maximize the utilization of the two transmission facilities.
摘要:
Crime investigation methods, evidence generation methods, and wireless communications system analysis methods are described. According to one aspect, a crime investigation method includes receiving information regarding a commission of a crime at a time period of interest and at a geographic location of interest, after the receiving and using wireless communications analysis equipment, measuring cellular signals in a geographic area which includes the geographic location of interest during the time period of interest, as a result of the measuring, generating measurement data which is indicative of a parameter of the cellular signals in the geographic area, using the measurement data, calculating a wireless coverage representation for the geographic area and which includes the geographic location of interest, accessing cellular communications records which are indicative of communications via the cellular signals in the geographic area, and using the cellular communications records and the wireless coverage representation, providing information regarding the crime.
摘要:
The handoff management system maximizes the communications capacity available from terrestrial air-to-ground cellular networks, while also integrating communications capabilities from satellite air-to-ground cellular networks and terrestrial cellular communications networks. The communications capacity is maximized by dynamically allocating communications from the aircraft over multiple communications channels to multiple cells of the terrestrial air-to-ground cellular network, and to satellite air-to-ground cellular networks and terrestrial mobile networks. This approach effectively provides an increase in the call handling capacity available to any aircraft and permits a gradual transition of communications from one cell to the next cell, rather than requiring an abrupt handover of all traffic from the aircraft from one cell to the next cell.
摘要:
The air-to-ground cellular network for deck-to-deck call coverage provides call coverage to customers who are located in aircraft that are flying within the arrival/departure airspace of an airport by trifurcating the spatial coverage regions or volumes of space to solve the problems of inter-network interference while yielding air-to-ground cellular network coverage at any altitude. Three types of cells are considered: an Outer Cell, an Inner Cell and an Airport Cell. The Outer Cell is a macro cell covering a large volume of space and is one of many cells in the composite air-to-ground cellular network. The Inner Cell is created within an Outer Cell and has at its center an airport. The Airport Cell is a part of the Terrestrial Cellular Network (TCN), created by the present terrestrial cellular operators or service providers.
摘要:
Crime investigation methods, evidence generation methods, and wireless communications system analysis methods are described. According to one aspect, a crime investigation method includes receiving information regarding a commission of a crime at a time period of interest and at a geographic location of interest, after the receiving and using wireless communications analysis equipment, measuring cellular signals in a geographic area which includes the geographic location of interest during the time period of interest, as a result of the measuring, generating measurement data which is indicative of a parameter of the cellular signals in the geographic area, using the measurement data, calculating a wireless coverage representation for the geographic area and which includes the geographic location of interest, accessing cellular communications records which are indicative of communications via the cellular signals in the geographic area, and using the cellular communications records and the wireless coverage representation, providing information regarding the crime.
摘要:
The present Spectrum Sharing System implements spectrum reuse between aircraft-based Air-To-Ground (ATG) communication systems and Geostationary Satellite Service systems. This is accomplished by managing the radio frequency transmissions in the volume of space in which the aircraft operates, with interference between the Spectrum Sharing System and the Geostationary Satellite Service system being reduced by implementing reversed uplink and downlink radio frequency paths in the common spectrum. The Spectrum Sharing System also avoids interfering with Geostationary Satellite Services' earth stations which are pointed towards the satellites' orbital arc by relying upon a combination of the earth stations' highly directive antenna patterns and the Spectrum Sharing System ground station antenna pattern, and to avoid interfering with satellites in their orbital arc by assuring that power levels radiated in that direction by the Spectrum Sharing System ground stations are below the level that would create interference.
摘要:
A method and apparatus for performing blind signal separation in an orthogonal frequency division multiplexing (OFDM) multiple-input multiple-output (MIMO) system are disclosed. A transmitter generates a plurality of spatial streams of data and transmits the spatial streams via a plurality of transmit antennas. A receiver receives the transmitted spatial data streams with a plurality of receive antennas and generates a plurality of receive data streams. The receiver performs a discrete Fourier transform (DFT) on each of the receive data streams to generate a plurality of frequency domain data streams. The receiver then performs a blind signal separation on the frequency domain data streams to recover spatial streams transmitted by the transmitter. The blind signal separation may be performed by using an independent component analysis (ICA) in the complex domain. The blind signal separation may be performed individually for each OFDM subcarrier.
摘要:
The handoff management system maximizes the communications capacity available from terrestrial air-to-ground cellular networks, while also integrating communications capabilities from satellite air-to-ground cellular networks and terrestrial cellular communications networks. The communications capacity is maximized by dynamically allocating communications from the aircraft over multiple communications channels to multiple cells of the terrestrial air-to-ground cellular network, and to satellite air-to-ground cellular networks and terrestrial mobile networks. This approach effectively provides an increase in the call handling capacity available to any aircraft and permits a gradual transition of communications from one cell to the next cell, rather than requiring an abrupt handover of all traffic from the aircraft from one cell to the next cell.