Abstract: A method of performing duty cycle correction of an input signal having a non-uniform duty cycle is provided. A signal representative of the difference in duration between the positive and negative portions of the input signal duty cycle is formed. A switching level is derived from the signal. An output signal is then formed through a switching action, whereby durations of positive and negative portions of the output signal duty cycle are defined by crossover points between the input signal and the switching level. The signal (and switching level) are adjusted, if necessary, until the output signal duty cycle is at least substantially uniform.

Abstract: A system and method for automatically directing a communication antenna to point to a desired wireless communication transceiver, is presented herein. The system includes a position location receiver, which receives signals indicating the position location information of the antenna and a position location transmitter and a processing mechanism, which determines calibration information of the antenna. The calibration information is achieved by first establishing a reference vector between the location of the antenna and position location transmitter and establishing a vector reference space and then calculate the necessary elevation and azimuthal components, within the vector reference space, to identify the proper calibration of the antenna. Once the calibration information has been determined, an alignment mechanism automatically orients the antenna.

Abstract: An efficient turbo decoder. The disclosed turbo decoder includes a first mode of operation in which the turbo decoder uses a first functional loop. The first functional loop includes a memory bank, a read interleaver, a first multiplexer (MUX), a RAM file, a log-MAP decoder, a write interleaver, and a second MUX. The disclosed turbo decoder further includes a second mode of operation in which a second functional loop is used. The second functional loop includes the memory bank, the first MUX, the RAM file, the log-MAP decoder, and the second MUX. The memory bank is a dual port extrinsic memory. The disclosed turbo decoder circuit switches between the first mode and the second mode.

Abstract: A method and apparatus whereby a remote unit in a slotted mode wireless communication system may calculate accurate time throughout its entire active state. In the remote unit a “wall clock time” is calculated from a modulo 80 counter called a combiner time counter. When a remote unit enters its inactive state, counters within the remote unit, including the combined time counter, are deactivated. When the remote unit reenters its active state, the value in the combiner time counter may not be correct in relationship to slotted mode time. A controller in the remote unit forces the combiner time counted to the correct phase resulting in the combiner being within 26.66 of the correct value. The controller then determines a combiner offset to compensate for any remaining error in the combiner time counter. The control may then use the combiner time counter and the combiner offset to calculate accurate wall clock time.

Abstract: An arrangement for protecting an element from electro-static discharge. A switch is provided to inhibit the flow of energy through the element in response to the control signal. In the illustrative embodiment, the switch is a transistor switch. A resistor is disposed between an input terminal of the transistor and the positive supply to keep the transistor on during normal operation. A capacitor is disposed between the input terminal of the transistor and ground to prevent the input voltage of the transistor from fast changing. The RC time constant is chosen to be much larger than the time constant of the ESD pulse. Consequently, input voltage of the transistor will remain unchanged near ØV and the transistor will remain off during ESD event preventing the element from conducting the discharge current and providing ESD protection.

Abstract: The present invention is a novel and improved method and system for performing the pilot frequency tracking operation for coherent demodulation in a system employing a gated pilot signal. In particular, the present invention describes a method and apparatus in which two frequency tracking loops operate in parallel. The first frequency tracking loop performs its tracking operation based on the hypothesis that the received pilot is continuous throughout the frame's duration. The second frequency tracking loop performs the tracking operation based on the hypothesis that the received pilot is discontinuous and is only present for a portion of the frame's duration.

Abstract: A transconductance filter (200) comprises multiple stages of a transconductor (110,120,130) having an input and an output, and a switch (260,265,270) coupled between the output and the voltage source. The switch is operatively responsive to the control signal for coupling and decoupling the voltage source directly to the output of the transconductor at least prior to the time the filter is required to filter the input voltage signal. The voltage source is within a predetermined input voltage range of the transconductor defined by a region in which a transconductance of the transconductor is substantially constant and positive.

Abstract: Radio frequency reuse between two or more radio frequency communications systems is facilitated by having a beacon transmitter broadcast information globally throughout an area, which information identifies to users of a second system, which radio frequency resources are already in use by a first communications system. The global broadcast of information as to what channels are in use, permits users in the second system to avoid interfering use of those frequencies.