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This is repeated, transmitting prescribed signals from other antenna elements using other transmit apparatus chains until prescribed signals have been transmitted from all antenna elements for which calibration factors are required. It would be clear to those of ordinary skill in the art that various modifications may be made to the methods, including without limitation, using segments of unequal length, using two sets of two tone signals separated by a known amount , and transmitting different combinations. The invention may be applied in a system comprising any antenna-array-equipped transceiver and another transceiver communicating with the array-equipped transceiver. With the above-mentioned method of determining signature reliability, Q ij has value 0 if the component is deemed unreliable or value 1 if it is deemed reliable. If the length of each convolving function is K, then rather than determining a complex valued M-weight vector w rx , one determines a complex valued M by K matrix W rx.

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Repetitive paging from a wireless data base station having a smart antenna system. The above generalization for determining the signature for M elements simultaneously can be modified to avoid transmitting the sum of all the M tones on one antenna element in the first segment.

General Purpose Limit Switches

Another feature of the invention generzl-purpose enabling determining the downlink spatial signature of a subscriber unit communicating with a communication station, the determining using only the communication station and the subscriber unit. The data then is repeatedly read out as a sequence of periods.

Remote calibration system for metering instrument and remote calibration method for metering instrument. The correction can be described as amplitude and phase corrections, or as corrections in in-phase I and quadrature Q components. There is no inherent need to define the concept of a base station or subscriber unit, and how to modify this description to accommodate the peer-to-peer case would be clear to one of ordinary skill in the art.

The function may be, for example, a principal component, an average, or a centroid. We have previously disclosed adaptive smart antenna processing including spatial processing with antenna arrays to increase the spectrum efficiency of SDMA and non-SDMA systems.


Another desirable feature is that the method can be used for signature estimation in order to also account for differences in the RF paths. It is known that compensation can be achieved by convolving each of the M signals received or transmitted by the antenna elements by a calibration function i. In addition, there are RF propagation effects that take place on the uplink between the subscriber unit and a particular receiving antenna, such effects including without limitation the path loss, fading and shading effects, multipath, and near-field scattering, and these effects may be different from antenna element to antenna element.

The mobile radio connection setup method and apparatus in a communication system. Radio communication method, radio communication system, and radio communication device.

Test Equipment & Calibration (new & used) Websites – RF Cafe

Calibration and repair of our electronic instruments is performed in our in house NIST traceable calibration lab. In another aspect of the Parish et al.

In order, there are four receive timeslots labeled 0 through 3 items,and followed by four transmit timeslots labeled 0 through 3 items25, and in FIG. The vectors a rx and a tx may be recognized as the un-normalized uplink spatial signature and downlink spatial signature, respectively, for the subscriber unit for this base station.

However, our invention also works when less signal processing power is available. Between each base station antenna element an element in [] and the antenna of the subscriber unit, there is a complex valued number that describes the phase and amplitude distortion that occurs in a baseband signal generxl-purpose to the RF propagation effects on the uplink and on the downlink.

The invention preferably is implemented in wireless cellular communication systems which include a base station i. In one embodiment, during calibration each antenna element of a particular subarray transmits a complex valued sine wave at a swirch frequency.

Multipath channel emulator formed by building rotary reflector in metal closed space. We also provide NIST traceable calibration services with quick turn-around, electrical systems training, and services. Compliance testing, signal generation, signal analysis and manufacturing test solutions, that are designed as per ZigBee IEEE Assuming identical RF propagation on the uplink and downlink, a single subscriber unit can be used together with its base station to carry out the calibration.


General-phrpose method of 1where the downlink signature related signals comprise the downlink signature for the remote transceiver. PIM testers and calibration services. Compensation techniques for group delay effects in transmit beamforming radio communication.

PXI Relay Module

The signals pass from the antenna elements through respective low noise amplifiers, and the signals thus received by each antenna element are measured by a beam forming apparatus. In this preferred implementation, one or more additional uplink calibration bursts and one or more additional downlink calibration bursts may needed, each for each additional subarray, and these additional steps are shown as dotted lines [] andrespectively in FIG. Another desirable characteristic for a calibration method micronetids the ability to determine whether calibration is accurate, switcu example by performing statistical measurements, together with the ability to feed back such information to the communication station to determine, for example, if the combining from several remote stations may be necessary.

CAE Online Menlo Park, CA CAE Online is the world’s largest marketplace for the purchase and sale of surplus semiconductor manufacturing and test equipment; We put buyers and sellers of like items in direct contact immediately. In an alternate embodiment, a local sense antenna at the satellite’s communication station is used to sample outputs of the transmit antenna elements. Year of general-;urpose payment: Provisional Patent Application Serial No.