Abstract: An intervote modulator (10) includes a majority voting logic unit (12) and an interplex modulator (14). The majority voting logic unit receives plural signal codes (e.g., five codes x1, x2, x3, x4, x5) together with their respective target gains G1, G2, G3, G4, G5 representing the desired transmit power for the individual signal codes. The majority voting logic unit combines three of these five signal codes to form a majority vote composite signal while keeping the other two signal codes uncombined. The majority vote composite signal and the two uncombined signals are then supplied to the interplex modulator as signals s1, s2 and s3. The interplex modulator applies interplex modulation to signals s1, s2 and s3 to form the in-phase and quadrature components of the final composite signal. The majority voting logic unit employs a generalized majority vote involving an interlace of sub-majority votes determined on a chip-by-chip basis.

Abstract: Systems and methods are described here for locating the position of a mobile terminal in a cellular communications system. A base station in the cellular communication system broadcasts a communication signal having embedded therein a navigation signal. The navigation signal uses a chirp technique in which the chirp signal includes two portions, an up-chirp portion and a down-chirp portion. Each portion of the chirp signal is synchronized with a frame in the communication signal. The chirp navigation signal is at a power level much lower than the communication signal so as not to interfere with the communication signal. A mobile terminal generates a corresponding chirp signal to correlate with the incoming signal and to extract the navigation signal. The mobile terminal uses the detected navigation signal to determine a time of arrival of the communication signal for use in determining the position of the mobile terminal either at the terminal or to send to a network center for location processing.

Abstract: CDMA codes are multiplexed into a constant-envelope composite signal using weighted majority logic. Based on a commanded power allocation among the signal codes, each signal code is assigned a weighting coefficient dictating the voting power the signal code has each time a vote is conducted, in a manner analogous to corporate shareholder voting. To multiplex the signal codes, a majority vote is conducted each chip period by summing the weighted chip values of the signal codes and assigning a binary value to the majority-voted composite chip based on the sign of the sum. An RF carrier is modulated in accordance with the value of the composite chip. The desired power distribution is achieved by requiring the power ratio of each signal code to be proportional to the square of the expected value of the cross-correlation between the signal code and a stored replica of the signal code at the receiver.

Abstract: A multiplexer and a method for chip-synchronous code-division multiple access (CDMA) signals produces a constant envelope signal. The output signal of the multiplexer permits use of a saturating (Class C) high power amplifier (HPA) resulting in a net increase in effective transmitter power usage. This multiplexer applies to a variety of CDMA spread spectrum modulation formats and has many applications, such as the IS-95 forward link interface, and CDMA and CDMA/FDMA (frequency-division multiple access) applications, including general cellular base station forward traffic channels, cellular subscriber station multiple-channel reverse traffic channels (e.g. IS-95 subscriber Internet access) and satellite downlinks.

Abstract: CDMA codes are multiplexed into a constant-envelope composite signal using weighted majority logic. Based on a commanded power allocation among the signal codes, each signal code is assigned a weighting coefficient dictating the voting power the signal code has each time a vote is conducted, in a manner analogous to corporate shareholder voting. To multiplex the signal codes, a majority vote is conducted each chip period by summing the weighted chip values of the signal codes and assigning a binary value to the majority-voted composite chip based on the sign of the sum. An RF carrier is modulated in accordance with the value of the composite chip. The desired power distribution is achieved by requiring the power ratio of each signal code to be proportional to the square of the expected value of the cross-correlation between the signal code and a stored replica of the signal code at the receiver.

Abstract: An intervote modulator (10) includes a majority voting logic unit (12) and an interplex modulator (14). The majority voting logic unit receives plural signal codes (e.g., five codes x1, x2, x3, x4, x5) together with their respective target gains G1, G2, G3, G4, G5 representing the desired transmit power for the individual signal codes. The majority voting logic unit combines three of these five signal codes to form a majority vote composite signal while keeping the other two signal codes uncombined. The majority vote composite signal and the two uncombined signals are then supplied to the interplex modulator as signals S1, S2 and S3. The interplex modulator applies interplex modulation to signals S1, S2 and S3 to form the in-phase and quadrature components of the final composite signal. The majority voting logic unit employs a generalized majority vote involving an interlace of sub-majority votes determined on a chip-by-chip basis.

Abstract: A water storage tank in the coolant water loop of a nuclear reactor contains a tubular heat exchanger. The heat exchanger has tubesheets mounted to the tank connections so that the tubesheets and tubes may be readily inspected and repaired. Preferably, the tubes extend from the tubesheets on a square pitch and then on a rectangular pitch therebetween. Also, the heat exchanger is supported by a frame so that the tank wall is not required to support all of its weight.

Abstract: The movable air baffle shield means in accordance with the present invention provides an efficient method of cooling the space surrounding the containment vessel while also providing the capability of being moved away from the containment vessel during inspection. The containment apparatus comprises a generally cylindrical sealed containment vessel for containing at least a portion of a nuclear power generation plant, a disparate shield building surrounding and housing the containment vessel therein and spaced outwardly thereof so as to form an air annulus in the space between the shield building and the containment vessel, a shield baffle means positioned in the air annulus around at least a portion of the sides of the containment vessel providing a coolant path between the baffle means and the containment vessel to permit cooling of the containment vessel by air, the shield baffle means being movable to afford access to the containment vessel.

Abstract: There is disclosed a method for rapid refueling of a nuclear reactor. The upper package including the head and upper internals and control rods of the reactor includes a missile shield and by engagement with the shield is moved to a refueling position in a single lifting operation exposing the core in the lower package. The fuel assemblies are then replaced. The removal of the control rods from the core with the upper package is compensated for by an increase in the concentration of neutron absorber, such as boron including B.sup.10, in the medium in which the core is immersed. Typically, the refueling can take place in a few days, at intervals of two to six months. During refueling a fraction of the assemblies are replaced. Because of the facility for rapid refueling and consequent lower time cycle for refueling, the fuel can be of low enrichment and the concentration of neutron absorber in the reactor coolant medium can be decreased.