A method of compressing or expanding the frequency of signals while keeping the signals' original gross temporal relationship relies upon an electrooptical processor. An apertured mask is interposed between an area-array charge coupled device (CCD) and a light emitting diode (LED). Optical signals are emitted from the LED at a clock rate which is the same as the vertical shift rate of charge packets in the CCD. Sampling the CCD's horizontal shift register output at varying rates allows a changing of the frequencies of the optical signals or a reoccurring reversal of sequential portions. Weighting the apertured mask to define at least one Gaussian curve or triangular waveform smooths and eliminates breaks in the compressed or expanded frequencies. Sampling the CCD output at a slower rate than the vertical clock rate compresses the frequency of the representative optical signals and if the CCD output is sampled at a faster rate then the signals will be expanded or rearranged in a sequentially reoccurring order. Thus, the electrooptic processor accomplishes a compression or expansion of signals with the signal's original gross temporal relationship and does not rely upon any mechanically displaceable parts. An optional approach employs a line-array CCD detector and a bidirectionally movable apertured mask to accomplish substantially the same end results; however, this introduces the problems usually associated with mechanical devices.
A method for underwater, acoustic transmission, characterized in that at the transmitting side, the signal to be transmitted first is sampled, digitized and stored and then un-sampled and un-digitized at a frequency less than the sampling frequency and is thus transmitted in analogue form, and in that at the receiving side the signal is correspondingly sampled, digitized and stored at the said un-sampling and un-digitizing frequency and then is re-read at the said sampling frequency.
An optical bit rate for communication systems. The optical bit rate converter converts an ultra-high speed optical data stream to a lower rate optical data stream. In one embodiment, the optical bit rate converter converts the ultra-high speed optical data stream to a lower rate optical data stream that can be detected and processed electronically. The optical rate converter includes a buffer presenting a repeating optical data bit pattern, an optical sampler presenting an optical sampling bit stream, and an optical correlator. The optical correlator has a first input in communication with the output of the buffer and a second input in communication with the output of the optical sampler. The optical correlator produces a rate-converted optical data bit stream at its output in response to the repeating optical data bit pattern produced by the buffer and the optical sampling bit stream produced by the optical sampler. In one embodiment, the buffer has a data input and stores an optical data bit stream received from a high speed optical data source. In another embodiment, the optical bit rate converter time dilates the repeating optical data bit pattern received from the buffer. In yet another embodiment, the optical bit rate converter demultiplexes the repeating optical data bit pattern received from the buffer. The invention also relates to a method for rate-converting an ultra-high speed optical data stream to a lower rate optical data stream.
The general purpose of the present invention is to provide a optimized procedure for performing matrix by matrix multiplication in a parallel architecture computer, either digital or optical, that is generally capable of handling two-dimensionally structured image data sets. The present invention provides a process for performing matrix by matrix multiplication in a parallel computer architecture having first and second means for representing spatially distributed data values obtainable from corresponding first and second matrices of values, said matrices having therein defined rows and columns of said values and said first and second data representing means having defined therein rows and columns of data representation positions, said architecture further having means for accumulating spatially distributed resultant values, the process comprising the steps of: (a) representing the respective data values of a first column of values of said first matrix in the corresponding rows of said first data representing means; (b) representing the respective data values of a first row of values of said second matrix in the corresponding columns of said second data representing means; (c) multiplying each of the values represented by said first data representing means with the spatially corresponding values represented by said second data representing means such that a matrix of resultant values is obtained, each resultant value being the product of the value of its corresponding row of said first column of said first matrix of values and the value of its corresponding column of said first row of said second matrix of values; (d) accumulating the respective resultant values as a matrix of cummulative resultant values; and (e) repeating steps (a)-(d) above for each successive column of said first matrix and correspondingly successive row of said second matrix.
A signal processing system processes an input signal in real time. The system includes a light valve array for selectively attenuating light incident thereupon in response to electronic control signals, a light source for providing illumination, a light-sensitive array for producing electronic output signals representing a processed version of the input signal in response to light incident thereupon, and control circuitry for generating and applying electronic control signals to the light valve array in response to the input signal. The electronic control signals are generated from the input signal and are adapted for implementing an arbitrarily-selected signal processing operation. The light valve array is situated between the light source and the light-sensitive array, such that the light source is selectively attenuated by the light valve array, and such that the selectively attenuated light is incident upon the light-sensitive array.
