Architecture and Construction of a Hardware Sequential Encoder for Speech

Recent work has shown the usefulness of sequential or "tree" encoding of speech. We report on construction of a TTL hardware multi-path sequential encoder which uses the so-called
M
algorithm search procedure. The device attains a signal-to-noise ratio of about 20 dB at 16 kbits/s. Hardware peculiar to this type of encoder is discussed, including architecture of the search algorithm sorter, the squared error calculator, and the code generator.