Pulse or digital communications – Spread spectrum – Direct sequence
Patent
1989-01-19
1992-08-04
Chin, Stephen
Pulse or digital communications
Spread spectrum
Direct sequence
358426, 381 29, H04B 166
Patent
active
051366185
ABSTRACT:
A method and apparatus for transmitting and/or storing a modulated signal via a medium whose bandwidth is less than the signal's bandwidth. The modulated signal is first broken into segments or sampled in discrete finite equl increments of time. Within the segment, the analog waveform is converted to digital elemental representations, such as by analog to digital conversion at a predetermined sampling rate, whereupon the analog amplitudes are converted to a sequence of a number of elements of digital numeric values. The quantity or number of elements within the sequence is selected as a function of a pre-selected finite unit of time of the bandwidth of the original modulated signal. An algorithm then processes the sequence to reduce the numerical sequence of the group into a single integer and a key number(s), which is unique to the sequence. These integers are then transmitted, in sequence, in digital form, via low bandwidth mediums. Alternatively, the integers may be stored for subsequent processing. Another matching, or inverse, formula is used to reconstruct the sequence from the integer and key(s), which is then read in order, and in real time, to recreate a representation of the digital waveform. This digital waveform is then converted to an analog modulated signal output.
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Chin Stephen
Redband Technologies, Inc.
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