摘要:
A communication device 10 and a corresponding method are arranged for changing the radiation pattern of an antenna 14, where the radiation pattern of the antenna 14 is set to a half-space pattern if the communication device 10 is in close proximity to an object. A reflector 18 is activated to produce the half space radiation pattern. The reflector 18 is deactivated to produce the full space pattern. A switching device 26 determines the state of the reflector 18. A sensing and control device 23 controls the state of the switching device 26.
摘要:
A subscriber device (10) includes one or more sensors (102) for measuring a object electromagnetic characteristic, such as conductivity, permittivity or permeability. A controller (104) stores the object electromagnetic parameter in memory (106) and, operating in accordance with a performance enhancement routine stored in the memory (106), enhances operation of the subscriber device (10) in accordance with the electromagnetic parameter. The controller (104) may do this by adjusting the power of an amplifier (112), the frequency of a synthesizer (114) or the impedance of an antenna (110). A software program controlling the subscriber device and a corresponding method are described.
摘要:
A method (600) and simulation tool (200) having enhanced accuracy and speed for simulation using ray launching in a mixed environment (20) by using adaptive ray expansion mechanisms can include a memory (204) coupled to a processor (202). The processor can select (602) a target area within the mixed environment and modify (604) the propagation properties of the adaptive ray expansion mechanisms according to characteristics classified for the target area. The processor can further classify characteristics for the target area by transmitting and reflecting rays for indoor building regions and for outdoor building regions. The number of bounces or a power level threshold assigned to a transmitted ray is a function of the environment where it propagates. The simulation tool can determine the target area or a region of interest by using a global positioning service device (230) externally attached to a device performing functions of the simulation tool.
摘要:
A system and method for determining a most likely material composition of an object (102). At least one respective stored radiation polarization transformation (500) is stored for at least one material composition at a plurality of wavelengths. A transmitted electromagnetic signal (112) with at least one wavelength within the plurality of wavelengths and that has a predetermined transmitted polarization profile is transmitted. The transmitted signal (112) encounters an object (102) and is received as at least one received signal (116, 118). Processing determines a respective received polarization for each of the at least one wavelength of the received signal (116, 118), determines a respective calculated polarization transformation between the transmitted polarization profile and the received polarization of the respective wavelength, for each of the at least one wavelength,. The processing also compares the respective calculated polarization transformations to the at least one respective stored radiation polarization transformations (500) for at least one of the plurality of material compositions and based on those comparisons, estimates a most likely material composition for the object (102).
摘要:
An orthogonal frequency division multiplexing (OFDM) transmitter method, consistent with certain embodiments of the present invention arranges OFDM data symbols representing data bits for transmission in a packet. A prescribed pattern of OFDM data symbols are removed (212) and replaced (216) with pilot symbols. The packet is then transmitted (220) to an OFDM receiver that receives the packet (224) and determines a channel correction factor from the pilot pattern. The receiver then estimates a plurality of channel correction factors, one for each of the plurality of OFDM symbols representing data (228) and uses these correction factors to correct the OFDM symbols representing data (232). Arbitrary data are then inserted in place of the pilot symbols (236). The OFDM symbols representing data along with the arbitrary data are then decoded using an error correction decoder that corrects the errors induced by substitution of the pilot symbols for data symbols (240).
摘要:
A method (20 or 500) and system (200) for method for computing wireless signal diffraction in a three-dimensional space can include the steps of selecting at least a source point, finding (19) sinkpoints that fail to have a line-of-sight path to the source point and storing the sinkpoints found, placing (21) diffraction points on all edges of a three-dimensional geometry, and building (24) a visibility matrix based on weighted paths for all source points and all sink points. The method can further include applying (25) a path finding algorithm on the visibility matrix for each sink point to all source points and storing store optimal paths for each source point to all sink points if they exist. The method can further include determining (23) if a last source point is selected before building the visibility matrix.
摘要:
A system (100) and method (400) for improving Radio Frequency (RF) Antenna Simulation is provided. The method can include determining (402) a proximity of an antenna (250) to a scattering structure (210), determining (410) a switching distance to the scattering structure that establishes when to switch the antenna on (416) and off (418) from a composite antenna pattern to a free space antenna pattern, and predicting RF coverage of the antenna responsive to the switching. The switching distance can be a function of a material type and a surface geometry of the scattering structure and a wavelength of the antenna. The method can also include evaluating a sensory mismatch in the antenna, and using a composite antenna pattern corresponding to the sensory mismatch.
摘要:
A system and method for determining a most likely material composition of an object. At least one respective stored radiation polarization transformation is stored for at least one material composition at a plurality of wavelengths. A transmitted electromagnetic signal with at least one wavelength within the plurality of wavelengths and that has a predetermined transmitted polarization profile is transmitted. The transmitted signal encounters an object and is received as at least one received signal. Processing determines a respective received polarization for each of the at least one wavelength of the received signal, determines a respective calculated polarization transformation between the transmitted polarization profile and the received polarization of the respective wavelength, for each of the at least one wavelength. The processing also compares the respective calculated polarization transformations to the at least one respective stored radiation polarization transformations for at least one of the plurality of material compositions and based on those comparisons, estimates a most likely material composition for the object.
摘要:
An antenna system (205) includes an antenna structure (215), a receiver (220), and an antenna system controller (225). The antenna structure includes an arrangement of antennas (237), a signal combiner (240), and a switching matrix (235). The arrangement of antennas is designed to have a set of antenna element separations that are optimized to provide lowest correlation coefficients of intercepted radio signals for a corresponding set of electromagnetic environment types that vary from a very low density scattering environment to a maximum density scattering environment. The antennas (230), (231), (232), (233), (234) in the antenna arrangement each include at least one element that has a common polarization. There is at least one antenna that is a dual polarized antenna. The antenna system selects an antenna element pair that corresponds to the environment type which it is operating and thereby receives a best combined signal.
摘要:
A system (100) and method (400) for improving Radio Frequency (RF) Antenna Simulation is provided. The method can include determining (402) a proximity of an antenna (250) to a scattering structure (210), determining (410) a switching distance to the scattering structure that establishes when to switch the antenna on (416) and off (418) from a composite antenna pattern to a free space antenna pattern, and predicting RF coverage of the antenna responsive to the switching. The switching distance can be a function of a material type and a surface geometry of the scattering structure and a wavelength of the antenna. The method can also include evaluating a sensory mismatch in the antenna, and using a composite antenna pattern corresponding to the sensory mismatch.