DIGICIPHER - ALL DIGITAL, CHANNEL COMPATIBLE, HDTV BROADCAST SYSTEM

General Instrument's DigiCipher(TM) System is an all digital HDTV system that can be transmitted over a single 6 MHz VHF or UHF channel. It provides full HDTV performance with virtually no visible transmission impairments due to noise, multipath, and interference. It offers high picture quality, while the complexity of the decoder is low. Furthermore, low transmitting power can be used, making it ideal for simulcast HDTV transmission using unused or taboo channels. The DigiCipher(TM) HDTV System can also be used for cable and satellite transmission of HDTV. There is absolutely no satellite receive dish size penalty (compared to FM-NTSC) in the satellite delivery of DigiCipher(TM) HDTV. This is important not only for DBS, but for broadcast and cable since broadcast network and cable programming is typically delivered to affiliates via satellite. To achieve the full HDTV performance in a single 6 MHz bandwidth, a highly efficient unique compression algorithm based on DCT transform coding is used. Through the extensive use of the computer simulation, the compression algorithm has been refined and optimized. Computer simulation results show excellent video quality for a variety of HDTV material. For error free transmission of the digital data, powerful error correction coding combined with adaptive equalization is used. At a carrier-to-noise ratio of above 19 dB, essentially error free reception can be achieved.