Design And Verification Of Multiple DSL Signal Transmission On Hardware Platform

Access network as a product of the era of the communications network, from birth to the development has been more than twenty years. In this short period of more than twenty years, the access network technology innovates from earlier copper access technology to the hybrid fiber-coaxial access in recent years, and even fiber DTH.These innovative technologies are driven by the rapid growth in demand for broadband services, but also need the support of sufficient funds for construction. Faced with all-fiber renovation costs, many countries and regions actually can not afford. Furthermore, in those areas where old buildings occupy the main proportion, copper access is still meet users’ requirements for broadband access. Just need to upgrade the center devices that near the client, strengthen its capacity to cover the end-user devices.Faced with these problems, on the basis of existing copper fibers mixed scheme, this thesis improves and optimizes the hardware device. At the same time hardware processing platform is validated.Firstly, this thesis presents the innovative solutions of multiple DSL signal multiplexing transmission access network. Originally closer to the user side of the central office equipments are pulled away to the center of the room, greatly enhance the ability of data processing and the service number of users of the center room. Near the user side to increase remote devices, leaving only the signal aggregation and separation function. Connected the distal and proximal device equipment via optical fiber.Then, depending on the overall demand for digital hardware platforms, from the signal processing module, data acquisition and reconstruction module, power module, the local clock modules are put forward their needs and performance analysis. According to the detailed requirements of each module processing platform is designed to support a set of 48 user channels and a single user up to 17.664 MHz channel bandwidth DSL access network RF direct sampling digital signal.Finally, in accordance with the requirements of the test project, under laboratory conditions fully test has been carried out. Relying on advanced hardware laboratory test platform and mature software testing technology, respectively between the FPGA core power supply voltage, clock source OCXO clock performance, PLL output clock frequency and performance, ADC or DAC key indicators one by one test. For the test results, a detailed analysis, and also the subsequent suggestions are promoted to improve the design.The thesis designed and successfully implemented the multiple DSL signal multiplexing transmission access network digital hardware platform, which passed the acceptance of the project performance and functionality. Program mix of fiber and copper, in the current DSL users still abound, the case of the last kilometer twisted need access still has a high feasibility.