| 摘要 |
PURPOSE: To efficiently transmit high-quality pictures by performing transmission with adaptive modulation in the case of high frequency components of a video signal and performing transmission by the method, which switches a wide band width to improve S/N, in the case of low frequency components. CONSTITUTION: The video signal supplied from a TV camera 10 is digitized by an ADC 12 and is sent to a filter bank 14 and is decomposed to many space components. A low frequency part including DC out of these components is coupled with an audio signal and a data signal by a preprocessor 16, and a high frequency part is processed by an adaptive modulator and is scrambled, and they are scent to a memory 20 through a multiplexer 22 and are converted into analog signals and are subjected to orthogonal modulation and are transmitted with a single carrier. On the reception side, a reception radio wave signal is sent to a tuner 28 and is shifted to a low frequency range and is converted into a digital signal by an ADC 30 and is subjected to digital detection in a means 32 and to automatic equalization in a means 34. The corrected signal is descrambled and is stored in a memory 36 indicated by an address generator 38 and is demultiplexed by a means 42, and low frequency components and high frequency components are demodulated by a means 46. |
