Bit-rate reduction method "HE-TCM"is described for high-definition television signals using Time Compression Multiplexing (TCM) and adaptive subsampling. Newly proposed adaptive subsampling method optimally applies four modes, corresponding to input video characteristics. This is applicable to an 8 MHz analog transmission system for HDTV signals, also compatible with 100 Mb/s transmission using intraframe DPCM. Simulation results show that the proposed method is superior to the method using non-adaptive quincunx subsampling not only in moving picture quality, but also naturalness and smoothness of picture.
A highly efficient coding algorithm called extrapolative and interpolative coding which uses an adaptive intraframe/interframe prediction has been proposed for HDTV signals. In this paper, a concrete system confniguration based on this coding algorithm is studied to transmit HDTV signals at about 100Mb/s-140Mb/s. which is the H4 channel rate of broadband ISDN. High quality coding system involving coding control techniques are investigated in detail taking into account of the hardware implementation. Computer simulation results showed that the proposed method can attain high quality coding for HDTV signals at a rate of H4 channel.
In this paper we describe a new DC-suppressed channel coding for DPCM. This coding method realizes effective DC-suppression by mapping a pair of 4-bit of neighbouring prediction error to an 8-bit transmission code. Simulated results about this channel coding are described as well as experimental results about HDTV digital VTR that uses this coding method.
New transmission method of Extended-Definition TV was developed. Quadrature modulation of picture carrier by the multiplex signal and reversal Nyquist filtering before adding to the main modulated NTSC signal reduce the interference of the multiplex signal on the conventional NTSC TV receivers which employ Nyquist filter on the IF stage. The transmission channel has about 1MHz capacity and suitable for various analog and digital signals as well as highs-component of luminance signal.
This paper provides some experimental results of serial transmission for component-coded digital video signals using optical fibers. The error rate is compared between two channel coding schemes ; scrambled-NRZ with a bit rate of 216 Mbps and 8-9 block coding with a bit rate of 243 Mbps. The scrambled-NRZ transmission has a lower error rate than that for the 8-9 code transmission. If the required transmission length is shorter than 1 km, a low cost laser diode, such as that used with Compact Disk, may be used.