Abstract: Simultaneous improvement in resolution, frequency range, dynamic ranges, as well as signal-to-noise ratio of spectrum analysis is possible by the huge increase in speed and capacity of digital data processing. In coherent pulse sounding (especially in monostatic Radar and Sonar), precise determination of the frequency, amplitude, and phase of wanted signals and unwanted interferers in the frequency domain and their elimination in the time domain data set leads to substantial improvement in the dynamic range of the analysis. Thus, a new apparatus and method of unevenly spaced transmitter pulses becomes feasible to increase the number of samples in a time period limited by the coherency requirements of the data set. The invented apparatus and method overcomes the inherent limitation in dynamic range of the spectral amplitudes due to cross-talk and sparse sampling. Non-linear spectrum analysis can improve signal-to noise further. Pre-cleaning of spread-spectrum data is another application of this method.

Abstract: Simultaneous improvement in resolution, frequency range, dynamic ranges, as well as signal-to-noise ratio of spectrum analysis is possible by the huge increase in speed and capacity of digital data processing. In coherent pulse sounding (especially in monostatic Radar and Sonar), precise determination of the frequency, amplitude, and phase of wanted signals and unwanted interferers in the frequency domain and their elimination in the time domain data set leads to substantial improvement in the dynamic range of the analysis. Thus, a new apparatus and method of unevenly spaced transmitter pulses becomes feasible to increase the number of samples in a time period limited by the coherency requirements of the data set. The invented apparatus and method overcomes the inherent limitation in dynamic range of the spectral amplitudes due to cross-talk and sparse sampling. Non-linear spectrum analysis can improve signal-to noise further. Pre-cleaning of spread-spectrum data is another application of this method.

Abstract: A method and apparatus for transmitting a message, in digital form, to or from a remote location. In a transmitter, a sequence of predetermined multiple-bit phase codes corresponding to the individual characters in the message phase modulate a carrier wave which also shifts frequency. At a receiving station, the various modulated carrier waves propagated through a dispersive medium constitute incoming signals with both frequency and range diversity. The receiver transforms the incoming signals into a sequence of quadrature component signals which it correlates with the multiple-bit phase code sequences to yield the digital representation of a transmitted message character at the receiving station.