Abstract: A fuzzy-logic spread-spectrum adaptive power control system comprising a base station and a plurality of remote units. The base station receives a spread-spectrum signal, and samples the despread spread-spectrum signal at a peak correlation time of the data channel, and at a non-peak correlation time of the data channel. This in turn generates a signal level and a noise level, respectively. A signal-to-noise ratio calculator generates a signal-to-noise ratio from the signal level and the noise level. A fuzzy-logic controller compares the signal-to-noise ratio to a set of predetermined thresholds, and using a state machine, generates a control signal which is thereby transmitted to the remote unit, indicating the amount by which to increase or decrease transmitted power. Each remote unit demodulates the control signal, and a transmitter controller adjusts a power level of the remote-unit spread-spectrum transmitter.
Abstract: A superior and scaleable architecture for implementing a large bit matched filter. The implementation of the bit matched filter requires less silicon and consumes less power as compared to the existing design. An effective way to turn the bit matched filter on and off for power saving is also disclosed.
Abstract: A system and method using a Costas loop to effect accelerated convergence with minimal system complexity. The system comprises an in-phase-limiter and a quadrature-phase limiter, operatively coupled to an EXCLUSIVE-OR gate, for exclusively-ORing an in-phase-sign signal and a quadrature-phase-sign signal to output a first error signal, responsive to the signals having same signs, or a second error signal, responsive to the signals having different signs. An AGC circuit, operatively coupled to an output of the EXCLUSIVE-OR gate, increases and decreases a voltage level of an AGC signal responsive to two consecutive first or second error signals and consecutive dissimilar error signals, respectively. A voltage-controlled oscillator, operatively coupled to an output of the AGC circuit and responsive to the increased or decreased voltage level, changes the frequency of a voltage-controlled-oscillator output signal.
Abstract: A spread-spectrum-matched-filter apparatus including a code generator, an in-phase-programmable-matched filter, a quadrature-phase-programmable-matched filter, an in-phase-frame-matched filter, a quadrature-phase-frame-matched filter, and a controller. The code generator generates replicas of a pilot-chip-sequence signal and a data-chip-sequence signal, which are used to set the programmable-impulse responses of the in-phase-programmable-matched filter and the quadrature-phase-programmable-matched filter. The programmable-impulse responses are alternately changed between that of the pilot-chip-sequence signal and the data-chip-sequence signal so that the in-phase-programmable-matched filter and the quadrature-phase-programmable-matched filter alternately detect the pilot-spread-spectrum channel and the data-spread-spectrum channel embedded in a received spread-spectrum signal, respectively.