Design and construction of the simple digital signal transmission performance analyzer
Feng Jie · Journal of Huanggang Normal University · 2011
The article proposes an approach to implement the measurement of the digital signal transmission performance on the project by using FPGA and the eye pattern,which mainly introduces its structure,the algorithm and the detailed principle of the implementation.Encoding and decoding the digital signal is based on EP1C6Q240C8N of ALTER company.By using three 2-order Butterworth low-pass filters and a pseudo-random signal generator to simulate the transmission channel.The filters use TI's OPA842 as the core chips.The addition circuit is THS4001.The shaping circuit uses LM331.The clock signal,M series,pseudo-random sequence and Manchester code are generated by FPGA,it's also used to recover the synchronous clock signal from Manchester code and decode at the same time.The 10MHZ pseudo-random sequence simulates the actual environment noise in the system.The system can encode the original signal,transmit it and get the demodulated signal finally,which implements the design and production of a simple digital transmission performance analyzer and ultimately measure the correct eye pattern.