| 摘要 |
<p>A hybrid D-PCM transmission system includes a transmitter in which an information signal x(n) is converted into a DPCM signal d(n) and an error reduction circuit in which this information signal x(n), or an estimated version thereof, is quantized and encoded to provide an error reduction signal y(n) which is added to the DPCM signal d(n), resulting in a sum signal s(n). In an associated receiver, a locally obtained error reduction signal y'(n) is subtracted from this sum signal s'(n) and the difference signal d'(n) thus produced is converted into a local version x'(n) of the information signal. This last-mentioned information signal is quantized in a local error reduction circuit and encoded to produce the local error reduction signal y'(n). In the transmitter, means are also provided for producing a quantization error signal component q(n) which is added to the sum signal s(n) for transmission. Equivalent means are provided in the receiver for producing a local quantization error signal component q'(n) which is subtracted from the received signal z'(n).</p> |
