Motorola Corporation

Westell, Inc.

Javier J Tapia

Jeff L Pfeil

Stephen W Henderson

Alan P Rottinghaus

Paul E O'Neil

Richard R McBeth

An apparatus (,) and method dynamically allocates radio frequency receive path resources as required by a programmable location engine (,). The programmable location engine (,) employs cascaded time of arrival and direction of arrival algorithms to determine per remote unit location data. The apparatus (,) employs a phased array antenna (,) and a programmable receiver switching apparatus (,). A plurality of radio frequency receivers (,) receive a plurality of different carriers, such as CDMA carriers, on each of a different phased array antenna element (,). An RF switching matrix (,) and mobile location shared resource controller (,) dynamically switch the plurality of radio frequency receivers (,) to not only receive the different carriers on each of the different phased antenna radio elements to determine time of arrival information, but alternately receive a same carrier signal over all or a portion of the phased array antenna element to determine direction of arrival information.

Method and apparatus for determining remote unit location using phased array antenna elements

A method and apparatus for estimating mobile radio channel parameters by dynamically determining the delay offset, carrier frequency offset, and coherent averaging length that yields the optimum despreading gain for current channel conditions. Obtaining the optimal despreading gain increases the fidelity of desired channel parameter estimates, (such as delay, phase, and the complex impulse response), and also expands the range of conditions under which they can be feasibly measured. A plurality of delay offsets, carrier frequency offsets, and coherent averaging lengths are considered for each measurement of channel parameters. An energy metric assigned to each combination of delay offset and coherent averaging length, and this value measures the despreading gain for these conditions.

Method and apparatus for estimating a channel parameter

Determining a timing offset for remote-unit (,) location is accomplished by comparing a known sequence (,) to the information (,) transmitted by the remote unit (,) and received by the remote site (,). In the preferred embodiment of the present invention a correlation window length (or size of the known sequence (,)) is allowed to vary based on a fundamental geometry of the serving and non-serving base stations, and a distance that the remote unit (,) is from the serving and non-serving base stations (,).

Method and apparatus for locating a remote unit within a communication system

A base station (101) calculates a location of a remote unit (113) using a first location technique. The first location technique is a single-site estimation of a PN offset for the remote unit (PN.sub.primary.sbsb.--.sub.site). PN.sub.primary.sbsb.--.sub.site is then forwarded by the base station (101), along with its base station identification, to locating equipment (107). Equipment (107) then passes a second location request to the serving base station (101) and those base stations neighboring the serving base station (neighbor base stations). PN.sub.primary.sbsb.--.sub.site is sent with the second location request, along with an identity of the base station that made the first location estimate. The neighboring base stations then calculate a 'search window' for each base station to search when locating the remote unit (113). The search range is based on the first location, and the identity of the base station that made the first location estimate.

Method and apparatus for locating a remote unit within a communication

A multi-variate system having a microprocessor-based telecommunications interface which has a digital adaptive all-pass filter and automatically variable delay distortion equalization circuitry which in combination provide both pre and post delay distortion equalization on the transmit and receive sides of bidirectional data lines (or dedicated telephone lines), which interfaces a conventional 4-wire analog facility and a data station termination at the customer premises equipment. A method of practicing the preferred embodiment of the invention is also disclosed.

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Wheaton, IL, United States of America

Javier J Tapia