Self-adapting anti-jamming device having (n + 1) sensors and enabling the restituting of the signal emitted by a source in the presence of n punctiform noise sources, comprising a combination assembly having an adder and n subtractors, an orthonormalization assembly comprising n AGC circuits, n (n - 1)/2! subtractors each combined with a correlation module, an intercorrelation set comprising n correlation modules, an adder and a subtractor.

Adaptive antenna processing

A system and method for transmitting a plurality of spread-spectrum signals over a communications channel having fading. The plurality of spread-spectrum signals are radiated by a plurality of antennas, with each antenna preferably spaced by one-quarter wavelength. A plurality of receiver antennas receive the plurality of spread-spectrum signals and a plurality of fading spread-spectrum signals. Each receiver antenna is coupled to a plurality of matched filters having a respective plurality of impulse responses matched to the chip-sequence signals of the plurality of spread-spectrum signals. A RAKE and space-diversity combiner combines, for each respective chip-sequence signal, a respective plurality of detected spread-spectrum signals and a respective multiplicity of detected-multipath-spread-spectrum signals, to generate a plurality of combined signals. The symbol amplitudes can be measured and erasure decoding employed to improve performance.

Multiple-input multiple-output (MIMO) spread-spectrum system and method

An adaptive signal processor including a network that adjusts itself on the basis of power maximization to resolve a raw composite input signal structure at least approximately into its separate statistically independent self-correlated components, or eigenvectors, and automatic gain control circuits for equalizing the power levels, or eigenvalues, of these components. The equalized component signals may be used as inputs to conventional adaptive systems, providing improved settling speed and dynamic range, or may in some cases be used directly, without further adaptive processing.

Signal processing method and apparatus

A space diversity communication system is presented in which the effects of signal fading are reduced through the cooperative receipt by closely spaced antenna sensor elements and the processing in a hybrid network of signals originally transmitted as a single intelligence-modulated carrier, though susceptible of multiple path propagation. Sum and difference signals are developed for analysis in a novel diversity signal selector or combiner. In one form, the latter may develop signals for electronically steering the system receptivity pattern so as to maximize the reception signal-to-noise ratio.

Angle diversity communication system

When two substantially identical signals contaminated by uncorrelated noise are received over two channels, combining of the contaminated signals in a linear manner results in a maximum signal-to-noise ratio improvement of 3 dB. The present disclosure relates to combining such contaminated signals through a process whose parameters vary as short time functions of the signal and noise powers in each channel. This processing produces a signal-to-noise ratio improvement which is greater than that achievable through linear processing.

Processing of two noise contaminated, substantially identical signals to improve signal-to-noise ratio

Device for improving the signal/noise ratio S + B1 and S + B2 coming from two aerials, comprising two correlators with polarity coincidence, whose first inputs receive chopped tensions x + y and x - y, x and y being sinusoidal voltages depending respectively on the correlation coefficients of noise B1, B2 and of the said noise put in phase coincidence, and whose second inputs receive chopped tensions S + B1 and S + B2, the required signal being collected at the output of an adder whose inputs are connected to the outputs of the said correlators.

Georges Levasseur

Papers

Apparatus for improving the signal to noise ratio of signals received at two antennas