Apparatus for Identifying Coded Information without Internal Clock Synchronization.
DEPARTMENT OF THE NAVY WASHINGTON DC
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Document describes a self-synchronized apparatus for recognizing identifying codes especially on missiles and spacecraft. The apparatus compromises a video quantizer for receiving bipolar video input signals and providing an output of validly timed data to a decode register which is clocked by a free running oscillator. The decode register defines a valid mark as K high bits followed by K low bits where 2K is the capacity of the decode register. A constant width decoder compares the first K bits in a sequential, pairwise fashion with the inverse of the values of the second K bits. The constant width decoder ANDs the pairwise comparison outputs to insure that K high bits are followed by K low bits beforea mark signal is produced. A derivative data buffer receives the mark signals. A synchronous counter is coupled to the derivative buffer and the free running oscillator to produce one output pulse for every N oscillator output pulses. The inputs of the derivativel buffer presets the sync counter to synchronize the derivative clock output with the actual data as transmitted.
- Air- and Space-Launched Guided Missiles
- Unmanned Spacecraft