| At present, a lot of countries have already launched the digitized business of the TV in the whole world, among them the some developed countries of Europe are the most general, Japan and S. Korea of Asia are highly popular, such countries as Singapore, India, etc. have already started too. In the course of developing in digital TV, the more important thing is it to grasping and formulation of relevant standards with key technology of independent intellectual property rights. Have already formed two major coalitions of companies represented by U.S.A. ATSC and European DVB to organize in the world, have made the digital television standard which represents each interests separately, and popularize in the brute force from all parts of the world. But there is not a unified national standard yet in the digital TV at present in our country. So, master the key technology with independent intellectual property right , must accelerate the formulation about the national standard.The digital cable TV is in very important position in the transmission means of digital TV. The main access way that urban residents watch the TV is the cable TV at present in our country. It have huge user colony, transmit as to satellite and ground is it have the masses of development prospect to say to come to transmit. So, formulation and obtaining the digital television transmission with China's autonomy of the digital wired television transmission standard to our country of study on the channel code of DVB-C and transmission system The standard has very great meanings.And key technology that this text has explained popular digital TV is made up of line transmission system one in the world now, research ATSC and DVB-C two digital TV wired technical specification and performance characteristic of transmission system these, communicate to System View system artificial function of software do brief introduction , on this basis, utilize System View three QAM in DVB-C modulate demodulation , basic module and whole transmission system , compiled code of RS and person who interweave of convolution carry on emulation, and analyse , have evaluatedperformance of DVB-C system to the result.Through emulation analyse can find out , adopting DVB-C system that 32QAM modulate can hold valid load capacity of 32Mbit/s in channel of 8MHz.Error code rates is under 10"7 . Spectral efficiency is up to 4.3 bit/s/Hz . The systematic cost is relatively low.lt is the first-selected scheme carrying on the digital television transmission in our country's existing CATV network at present. |
PDF Full Text Request