Abstract: A method is provided for decoding an encoded signal that includes a series of encoded digital data messages. Each message is encoded in such a way that each bit thereof is contained in the ordering of a complementary bit pair. Each encoded message is separated by a plurality of non-complementary bits. Decoding is provided by simultaneously analyzing a plurality of bit pairs of the encoded signal and producing an output when there are identified (i) a string of complementary bit pairs having a length in pairs equal to the number of bits in one of the messages and (ii) a plurality of non-complementary bits in at least one of the positions immediately preceding or immediately following the string.

Abstract: A non-binary digital encoding/decoding process wherein the serial bits to be transferred are encoded into a stream of complementary-bit-pairs, a predetermined bit of each pair corresponding to an original information bit, and the other bit of the pair being the complement of that bit. This stream of encoded complementary-bit-pairs is transferred, as by a communication or information-storage medium, to a decoder where the encoded stream is fed to and along a shift register. The bit-pairs in the decoder register are continuously examined for complementary relationship as the encoded stream is shifted along the register. The resulting signal generated in the decoder enables transferral of only error-free serial information out of the register, due to the error-detection properties inherent to the encoding/decoding process.

Abstract: An apparatus for producing a signal which varies as the ratio of the frequency of a first stream to a second stream. In a preferred embodiment of the apparatus, the first stream is transformed into a first signal of value proportional to the frequency of the first stream, and the second stream is transformed into a second signal that has a value proportional to the product of the second stream frequency times a feedback value. The feedback value is derived from a combination of the first and second signals.

Abstract: Apparatus and method for reducing flutter noise in a frequency-modulated data stream, wherein the data stream is combined with a reference stream which has been modified by the fed-back result of the combination. Before combination, the data stream is transformed into a first rectangular-pulse stream in which amplitude is constant and frequency is dependent on the frequency of modulation of the data stream, whereas the reference stream is transformed into a second rectangular pulse stream of amplitude which is dependent on the fed-back result of the combination of the streams, and the frequency is dependent on the frequency of modulation of the reference stream.