Abstract: An amplifier circuit 11 comprises an amplifier 12, an indicator of desired power 15, a power control circuit 14 and a power measuring circuit 13. The amplifier 12 amplifies an input signal to produce an output signal, and has an input for controlling a supply current I and an input for receiving a supply voltage V and supply current I, for driving the amplifier. The power control circuit calculates and applies values of both a supply voltage V and a supply current I, according to any one of a plurality of desired power levels, in order to operate the amplifier with maximum efficiency over a wide range of power levels. The power control circuit may further comprise a power control loop whereby adjustment of the output power can also be effected according to a measurement of output power and a desired level of output power.

Abstract: The present invention is a novel and improved method for providing broadcast short message services (SMS) in a communication network. It is an objective of the present invention to provide a method and apparatus that insures the successful transmission of the broadcast message while minimizing the impact of providing the short messaging service on overall system capacity. It is further the objective of the present invention to provide a method and apparatus for receiving broadcast messages without depriving the receiver of the benefits of slotted paging, that being the savings in power consumption.

Abstract: A system and method for communicating information signals using spread spectrum communication techniques. PN sequences are constructed that provide orthogonality between the users so that mutual interference will be reduced, allowing higher capacity and better link performance. With orthogonal PN codes, the cross-correlation is zero over a predetermined time interval, resulting in no interference between the orthogonal codes, provided only that the code time frames are time aligned with each other. In an exemplary embodiment, signals are communicated between a cell-site and mobile units using direct sequence spread spectrum communication signals. In the cell-to-mobile link, pilot, sync, paging and voice channels are defined. Information communicated on the cell-to-mobile link channels are, in general, encoded, interleaved, bi-phase shift key (BPSK) modulated with orthogonal covering of each BPSK symbol along with quadrature phase shift key (QPSK) spreading of the covered symbols.

Abstract: A method and system that enables faster acquisition of the forward link signal of a target base station in a mixed network of synchronous and asynchronous base stations is disclosed. The serving base station transmits in a neighbor list an estimated timing error 417 between the serving base station and a target base station. By utilizing the timing information, a mobile station estimates the relative time offset 408 between forward link signals received from the serving base station and signals received from the target base station. Timing information acquired during handoff enables accurate updating of the estimated timing error 417 subsequently transmitted in the neighbor lists by the base stations.

Abstract: A phase-locked loop has associated with it a first register set (21) for holding data defining a mode of operation of the phase-locked loop; and a second register set (22) for holding data defining a mode of operation of the phase-locked loop. Switches (27 to 30) for coupling one of the first and second register sets to receive data defining a new mode of operation while the other of the first and second register sets is connected to the phase-locked loop to cause the same to operate in the mode defined by the data in the other register set. The switches are reconfigurable to change the coupling so that the other register set is coupled to receive data defining a further new mode of operation while the one register set is connected to the phase-locked loop to operate in the new mode of operation.

Abstract: A system and method for rapidly acquiring timing of an access transmission that uses an access probe that is transmitted in stages. A first stage of the access probe is spread with a short pseudonoise (PN) code pair. A second stage of the access probe is spread with both the short PN code pair and a long PN code. Transmitting the access probe in stages reduces the number of hypotheses, and hence the time, required by a receiver attempting to acquire the access probe.

Abstract: A stripline tapped-line filter is disclosed including a first substrate upon which a plurality of N hairpin resonators are disposed alternately on opposite surfaces of the first substrate. Each one of the hairpin resonators is in a parallel coupled relationship with an adjacent hairpin resonator disposed on an opposite surface of the first substrate. The first and last hairpin resonators each have an interconnected member disposed on the substrate for respectively coupling a signal into and out of the plurality of N hairpin resonators. Second and third substrates are included with each being respectively located adjacent to ones of the plurality of N hairpin resonators on opposite surfaces of the first substrate. First and second groundplanes are included with each respectively located adjacent the second and third substrates.

Abstract: A ballistic comparative ohmmeter for use in testing the resistance between different selected pairs of a plurality of terminals in a test circuit in comparison to the resistance between corresponding pairs of terminals in a reference circuit. the ohmmeter is particularly useful for making resistance tests in circuits included in assembled products. The ohmmeter makes comparative resistance tests during a transient response period following application of the current to the selected pair of terminals as well as under steady state conditions. Solid state stepping switches that are sequentially stepped by pulse counters are utilized to sequentially connect different combinations of terminals in the test circuit and the reference circuit. Protection circuits limit the voltages applied across the test circuit and master circuit terminals. Indicator panels immediately provide a steady state indication of the pair of terminals in the test circuit at which a fault is detected.

Abstract: Apparatus is provided for detecting the presence of acoustic signals which includes a laser source, and a detector coupled to opposite end of an acousto-optic transducer. The transducer may employ fiber optic waveguides, etched to allow evanescent coupling therebetween, and disposed within a flexible housing. Integrated and planar optic transducers are provided in various forms employing two integrated optic waveguide channels, two planar waveguides, or a planar waveguide and absorber combination. Each configuration is disposed within a flexible housing and the waveguides are separated from each other by a predetermined distance. Any flexing of the housing is transformed into a displacement of the waveguides relative to one another. The coupling between the waveguides is a very sensitive function of distance, and hence detection of variations in the energy coupled by the waveguides provides an indication of the presence of the acoustic signals.

Abstract: Apparatus is provided including a light source, a transducer and a detector, which is capable of detecting applied acoustic signals. The transducer employs first and second ridged members which have parallel rippled surfaces which contact opposite sides of a fiber optic waveguide. Each rippled surface has a different predetermined ripple pitch which provides for variable sensitivity along one dimension of the transducer. Modulation of the position of the ridged members relative to one another by means of applied acoustic signals causes microbend attenuation of light transmitted through the waveguide. The modulation of the light provides an indication of the presence of the acoustic signals. The variation in dimensional sensitivity provided by the transducer allows for a determination of the direction of arrival of the acoustic signals. Appropriate selection of pitch and pitch ratio of the two rippled surfaces provides any desired spatial sensitivity distribution of the hydrophone.