Motorola Corporation

Jeff L Pfeil

Javier J Tapia

Stephen W Henderson

Louay A Jalloul

Paul M Erickson

Alan P Rottinghaus

Edward S Golovin

Darek Blasiak

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 method and apparatus for determining an angle-of-arrival (AOA) of the prompt ray at an adjacent sector of a base station is provided. High precision parameter estimates from a main sector location searcher (,) are provided to an adjacent sector location searcher (,) in order to enhance the accuracy of the parameter estimates generated by the adjacent sector location searcher (,). Main sector time-delay and phase estimates may be used as estimates for the adjacent sector time-delay, and phase estimates to increase the coherent averaging window within the adjacent sector location searcher, and hence to increase the accuracy of the amplitude estimation from the adjacent sector location searcher.

Method and apparatus for determining an angle of arrival of a transmitted signal in 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-site communication system (100) includes a plurality of communication units (106, 107) roaming among communication sites (108-111). The communication sites (108-111) are controlled by a central controller (100), via repeaters (102-105), and are thereby capable of establishing communication among sites. A method for minimizing message interruptions during a hand-off, of a first communication unit between two sites, includes the step of receiving (200) a message (300) from a second communication unit. During the message (300), which may be delivered at varying information rates, the first communication unit determines (202) the signal quality. If the signal quality of the message is unfavorable, the receiving communication unit determines (204) when the varying information rate of the message is favorable for a hand-off. Lastly, when the varying information rate is favorable for a hand-off, the first communication unit requests (205) the hand-off.

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Bartlett, IL, United States of America

Jeff L Pfeil