Design Of Multi-channel Digital Television Signal Combiner

In recent years, technology of terrestrial digital broadcast system has brokenthrough, in the implementation and the popularization process of terrestrial digitaltelevision broadcasting standard, it always refers to use the terrestrial digitaltelevision single frequency network transmission. This article designs a product tosuit for a variety of transmission methods for single frequency network transmissionspecifically to improve the utilization rate of the channel and save the spectrumresources, it calls ASI Combiner.ASI combiner is mainly composed of two parts, a control system and acombiner. This paper has designed the hardware part of the control system and thecombiner and chose based on ARM Cortex-M3kernel STM32F107RCT6chip asthe main control chip of the product. There is a Ethernet MAC controller in the chip,so it can realize the function of webpage control of the combiner. The peripheralcircuit of the main control chip contains reset circuit, power supply circuit, JTAGdebug circuit, clock circuit and so on. EEPROM memory circuit is designed byAT24C64chip, Circuit of Ethernet controller and the interface is designed byDP83848chip and HR911105chip. The paper designs the key circuit, LCD circuitand the load switch circuit of LCD to realize the key-press function of the combiner.The Combiner chooses the Cyclone II FPGA series EP2C8as the core function of thechip. The receiver and transmitter are designed by CY7B933/923chip.This paper completes the program of the combiner control system code with theC language in MDK compiler environment. It realize the real-time monitoring of thecode rate and the combiner webpage control by transplanting LwIP protocol,moreover it adds other functions such as Password modification, IP addressmodification. The paper designs the function of combiner key control for theconvenient operation, it controls the open or close state of the combiner by changingthe key, the port number and rate can be displayed on the LCD screen. This paper also designs the SPI communication procedures, controlling the combiner port andreturning the code rate are completed by reading and writing registers. PC andcombiner man-machine interface is developed by HTML language, it displays allcombiner control function.ASI Combiner can be used in CMMB, DVB-T, DTMB and other networksystems. It uses the shelf structure and the1U standard chassis, it is available for thedata information transmission in Military and Civilian, it can be also used in all kindsof radar intelligence transmission. The conbiner conbines6TS Stream into1TSStream for satellite launching transmission without changing each code streaminformation. It can deliver the information to all the launcher through a physicalaccess, in the aspect of the quality of transmission and anti-jamming ability, thesystem is guaranteed, it makes full use of the program network to allocate theresource efficient, reduce the transmission cost.