Nippon Hoso' Kyokai

Satoru Koizumi

Toshiyuki Takegahara

Hideki Suganami

Takeshi Kimura

Yoshiharu Hoshino

Yoshimichi Otsuka

Kozo Kameda

Yutaka Tanaka

Shoichi Suzuki

Kaoru Watanabe

Taiji Nishizawa

Taiichiro Kurita

Kazumasa Enami

Yasuaki Kanatsugu

Haruo Okuda

Ryoichi Yajima

Hisakazu Kato

As to a differential code (DPCM) transmission system for an input signal as such as an audio signal, in case higher frequency components thereof are dominant, every another samples of the input signal are alternately into two groups, in each of which differential coding effected, so as to maintain a dynamic range in higher frequency range; in case no frequency components exceeding one fourth of the sampling frequency are contained in the input signal, successive 3 MSB's having a pattern '1, 0, 1' or '0, 1, 0' are corrected into '1, 1, 1' or '0, 0, 0' respectively; and in case 2 symbols of a tertiary code converted from 3 bits of a binary code are transmitted and restored, peripheral bit arrangement of a matrix having rows consisting of the first symbols of the converted tertiary codes and columns consisting of the second symbols thereof are allotted such as Gray codes are obtained, while an inner 2.times.2 matrix of a 4.times.4 matrix formed by inserting a new threshold level between two threshold levels provided for detecting the tertiary code is allotted with bits relating to bits arranged at adjacent positions, so as to reduce the bit error rate of the restored binary code.

Differential code transmission system

A signal transmission system for high definition television that can handle a second television signal which is superior in quality to a first television signal such as an NTSC (National Television System Committee) television signal. The transmitting end of the system transmits a first television signal including a video signal, audio signals, etc., through a main transmission line, as well as a third television signal including a high definition components obtained as the difference between the second and the first television signal through an auxiliary transmission line. The receiving end of the system receives and synthesizes the first television signal transmitted through the main transmission line and the third television signal transmitted through the auxiliary transmission line to produce the second television signal.

Signal transmission system for high definition television

A differential code (DPCM) transmission system for an audio signal, in case higher frequency components thereof are dominant, every another samples of the input signal are alternately into two groups, in each of which differential coding effected, so as to maintain a dynamic range in higher frequency range; when a near instantaneously compressed DPCM signal is transmitted, coding errors caused by the compression are corrected by varying the difference between samples in response to the comparison between a locally decoded signal and the original signal; when the frequency components exceeding one fourth of the sampling frequency are contained in the input signal, successive 3 MSB's having a pattern '1, 0, 1' or '0, 1, 0' are corrected into '1, 1, 1' or '0, 0, 0' respectively; and in case 2 symbols of a tertiary code converted from 3 bits of a binary code are transmitted and restored, peripheral bit arrangement of a matrix having rows consisting of the first symbols of the converted tertiary codes and columns consisting of the second symbols thereof are allotted such as Gray codes are obtained, while an inner 2.times.2 matrix of a 4.times. 4 matrix formed by inserting a new threshold level between two threshold levels provided for detecting the tertiary code is allocated with bits relating to bits arranged at adjacent positions, so as to reduce the bit error rate of the restored binary code.

Differential coding system

Growing community of inventors

Tokyo, Japan

Satoru Koizumi