Research On New Generation Broadcast Wireless Network Based On Bidirectional IP

With the ever-changing demand for terrestrial digital TV broadcasting,the original ATSC 1.0(Advanced Television Systems Committee)has been unable to meet the needs of users and has not brought more benefits to broadcast service providers.Based on this,the ATSC(Advanced Television Systems Committee)has designated a new generation of digital TVs--ATSC3.0.ATSC 3.0 design goals,preparation ideas,especially the relevant advanced technologies based on the IP(Internet Protocol)protocol stack,which is undoubtedly of high reference value for countries and regions that may have similar needs,such as China's digital TV broadcasting system.Currently,China is vigorously researching and implementing the telephone network,the integration of the Internet and the broadcasting network.The advanced technology features of ATSC 3.0based on IP will provide practical support for China's development of a new generation of digital TV broadcasting systems.The main work of this paper includes three aspects.The first one is to address the waste of bandwidth resources in the existing commercial broadcast gateway data scheduling and bandwidth resource allocation,and proposes CANDA(Compare AND Adapt)based on statistical multiplexing.The algorithm implements rate adaptation and bandwidth dynamic allocation.The algorithm calculates the real-time code rate of each data stream in each physical frame duration in the ROHC(Robust Header Compression(ROHC)compression in the ALP package,and uses the exponential weighted moving mean function to the real-time code with the best value.The rate is smoothed to calculate the bandwidth required in real time.When the physical layer pipe(PLP)of the transport stream is multiplexed,the allocation is performed according to the required bandwidth.When the required bandwidth is slightly over 57 Mbps,this paper uses the method of adjusting the physical frame length to improve the transmission bandwidth of the system.When the required bandwidth exceeds the bandwidth limit of the transmission channel for a long time,the communication between the scheduler and the signal source informs the signal source to timely reduce the coding rate of the data stream.Compared with existing broadcast gateways,broadcast gateways that use CANDA algorithm to schedule data increase bandwidth resource utilization and diversity of transmission content.The second content of this paper addresses the problem of redundant information transmission in the inner layer encapsulation of the Studio-to-Transmitter Link Transport Protocol(STLTP).It is proposed to apply ROHC technology to STLTP.IP and UDP are fixed in the inner layer encapsulation of ATSC3.0.They are only used to extract the required preamble data and Timing data at the origin and the end,and there is no use of network layer addressing in the wireless transmission link..Therefore,we propose to apply ROHC to STLTP,which saves the overhead of RTP inner layer encapsulation IP/UDP header,thus improving the transmission efficiency of the system.The third content of this paper introduces two projects I participated in during my master's degree,namely the implementation of the ATSC3.0dedicated backhaul channel downlink and the 4K Ultra HD based on Multiple Input Multiple Output(MIMO).The downlink of the dedicated backhaul channel implements the scheduling and transmission of uplink data,and the proposal for the dedicated backhaul channel is included in the ATSC 3.0 standard to provide downlink guarantee.In the implementation process of MIMO-based 4K ultra-high definition program transmission link,the problem of originating power matching and receiving end spectrum overlapping is solved,thus realizing the industry's first MIMO-based 4K ultra-high definition program transmission in the external field environment.