Motorola Corporation

Timothy P Froehling

Louis Jay Vannatta

William Paul Alberth, Jr

Scott A Steele

Joseph F Cramer

Scott L Chamberlain

A method ( ) of enabling automatic frequency control (AFC) concurrent with time alignment of information in a communication device includes a first step ( ) of providing a data stream to an AFC. A second step ( ) includes applying multiple frequency offsets to the data stream. The offsets are separated from each other by about &plusmn;2&pgr;/2 radians with m being the number of bits per symbol in the modulation system. A third step ( ) includes correlating each frequency offset signal with a predetermined symbol sequence until correlation is found. A fourth step ( ) includes coupling the correct data stream of the branch with the found correlation to an AFC logic circuit indicating AFC lock. A fifth step ( ) includes simultaneously supplying the correct data stream to the communication device along with the fourth step ( ) such that time alignment can take place concurrently with AFC in the communication device.

Method and apparatus for concurrent synchronization and improved automatic frequency control in a communication device

A mobile station (102) has electrical circuitry (301) that operates to reduce power consumption. A synthesizer (318) is tuned so that a receiver (314) receives a home radio frequency (RF) signal during a receive slot (504) of a PCH subframe (209). A controller (310) detects if an upcoming subframe has an uplink requirement and if data from the home RF signal indicates that an idle condition exists. If the upcoming subframe does not have an uplink requirement, synthesizer (318) is tuned during a long idle slot (506) of PCH subframe (209) to measure signal strengths of two peripheral RF signals. If the idle condition does exist, electrical circuitry (301) is placed into a low power mode throughout a transmit slot (508), a receive slot (512), a long idle slot (514), and a transmit slot (516).

Method of and apparatus for reducing a power consumption of a

A frequency control circuit, and associated method, for a receiver operative to receive a TDMA signal transmitted by a transmitter in a TDMA communication system. A first frequency detector generates a first frequency control signal. A second frequency detector, comprised of a portion of a decision-directed demodulator, generates a second frequency control signal. The first frequency control signal is utilized to effectuate frequency control when a signal is continuously received by the receiver, such as times immediately subsequent to initial powering of the receiver as the receiver becomes synchronized with the TDMA signal transmitted thereto. Onces a receiver becomes synchronized to the transmitter, the receiver need only be powered during intermittent time periods when the TDMA signal is transmitted to the receiver. The second frequency control signal is utilized to effectuate frequency control only after the receiver is synchronized with the transmitter to permit intermittent operation of the receiver, and the frequency differences between the signal transmitted to the receiver and a receiver-oscillator, oscillation frequency is less than a maximum level.

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Palatine, IL, United States of America

Timothy P Froehling