89 results about "Adaptive antenna array" patented technology

An adaptive antenna array (14) includes a muliplicity of antenna elements (12a–12k, 48a–48k) responsive to uplink communications (16a–16k) and arranged to support directional-orientated downlink communication to subscriber units (18). The adaptive antenna array (14) is operationally responsive to a signal processor (28) that co-operates with direction of arrival estimation logic (36) to assess an angle of arrival of uplink communications incident to the array. To avoid inter-cell interference, especially during early stages of a call, the signal processor operates to ensure that a wide area downlink beam (108) is provided for a downlink path to an addressed subscriber unit. With time and / or with reported (68,84) downlink quality of service (QoS) metrics, the signal processor (28) regulates (74, 92, 96) a width of the downlink beam by altering the number of antenna elements used to support the downlink beam, thereby altering the downlink beam aperture. Generally, with time, more antenna elements (92) are used and so the beam is narrowed, although in-call fluctuations in downlink quality of service are dynamically addressed by the signal processor (28) by either narrowing or broadening the width of the downlink beam by respectively switching antenna elements (12a–12k, 48a–48k) into (92) or out (96) of the adaptive antenna array (14), as shown in FIG. 3.

Two or more antenna elements are arranged in the vertical direction to give vertical spatial adaptivity to a wireless discrete multitone spread spectrum communications system. The system is based on a combination of Discrete Multitone Spread Spectrum (DMT-SS) and multi-element adaptive antenna array technologies. This enables the automatic positioning of a beam in the vertical direction to position nulls where interferers are located on the same azimuth but are separated in elevation.

An apparatus comprises a distributed array of antenna elements for receiving a radio frequency signal on a satellite communications link, wherein the radio frequency signal includes a known preamble; a plurality of mixers for translating the radio frequency signal to a plurality of baseband signals having in-phase and quadrature components; a processor for applying weights to the baseband signals, wherein the weights are found adaptively in response to the preamble in combination with decision-directed feedback when the preamble is not present; and a receiver for processing the weighted baseband signals. A pre-processor can be used to create sub-arrays of the antenna elements using maximal-ratio weighting. A method performed by the apparatus is also provided.

A wireless network base station for optimizing the beam width of a downlink traffic beam in real time is provided. The base station includes a transceiver for receiving a pilot strength signal and a power control signal from a mobile station. The base station further includes beam forming circuitry operable to form a downlink traffic beam spatially directed to serve the mobile station having a beam width set as a function of the received pilot strength signal and power control signal.

This invention relates to a radio transmission method for multiple adaptive antenna arrays, in which, a mobile station utilizes MIMO empty time process technology to send signals from multiple antennas simultaneously when the mobile station transmits signals and the base station receives them, multiple intelligent antenna arrays receive signals simultaneously and transmit them to a base station process unit (BSH) via fiber links, which first of all carries out adaptive wave beam shaping process to the received signals of each intelligent antenna array then utilizes the MIMO technology to diversify and merge signals of the array, when the base station transmits signals and the mobile station receives them, the BSH divides the signals into multiple signals by MIMO empty time process then carries out adaptive wavebeam shaping to the multiple signals to be transmitted by multiple intelligent antennas at the same time, and the mobile station gets signals by related empty time process.

The present invention relates to use of a smart antenna for a RF reader on a Radio Frequency Identification (RFID) system to significantly increase the operating range of the RFID system. The smart antenna can be an adaptive antenna array. The smart antenna comprises a plurality of antenna elements and, by combining the signals from multiple antenna elements, significantly increases the received signal-to-noise ratio. In a noise limited environment, combining the signals to maximize the received signal-to-noise ratio can be based on the maximal ratio combining (MRC) principle. To achieve the best signal quality, the received signal from each antenna can be phase-shifted such that the resultant signals from all antennas are in phase. In addition, the signal from each antenna can be scaled in amplitude based on the square root of its received signal-to-noise ratio.

An adaptive antenna array has array elements arranged in element rows and element columns and subarrays arranged in subarray rows and subarray columns, for which the subarray phase centers have non-uniform spacing. The adaptive antenna array provides good detection and tracking performance when used in a radar system, while being inexpensive and easy to manufacture. A radar system and a method of adapting a radar array both employ the above described adaptive antenna array.

Systems and methods for on-the-fly characterization of an arbitrary array of antenna elements are provided. An array of arbitrary antenna elements and a reference receiver is provided. A location for a target source of signals is provided or assumed. Cross ambiguity functions are computed between the signal received by the reference receiver and the signal received by each antenna element. The cross ambiguity functions are analyzed to determine the phase and amplitude response of the antenna array to signals originating from the location of the target source of signals.

A group of inventions relate generally to radio engineering, and more particularly to a method of data transmission (embodiments) and apparatus of data transmission (embodiments) to be used, for example, in cellular communications systems when transmitting an information signal over the downlink from base station to mobile station. The goal of the present method of data transmission (embodiments) and the apparatus of data transmission (embodiments) is to increase the efficiency of the information signal transmission in the downlink and, thus, maximize the information signal reception quality at the mobile station. The claimed solution also reduces the feedback channel (from mobile to base station) load. The object of the invention is attained by correcting the spectrum of the transmitted information signal copies, transmitting the information signal copies from each adaptive antenna array in each efficient transmission direction, estimating the transfer functions of the directional transmission channels using the pilot signals transmitted from each antenna element, pilot signals for transmit diversity, transmitted from each adaptive antenna array in each efficient transmission direction, combining these two estimates, and by estimating the efficient transmission directions at the base station using the mobile station signal.