Research And Design On Multi-channel And Multi-rate Signal Transmission Using FPGA

Nowadays, with the acceleration of peple’s life, reqiurements for each industry is being improved, and each industry that based on electric technique also does that. Due to the high development of computer and integrated circuit technology, A/D and D/A sample rate is highly improved, and the fact that data collection, processing and transportation are widely used in the smart control, communication and medical treatment, the research for signal transportation become much more important. The signals received before signal transportation are analog signals.However, as we all know, computers only can recognise digital signals, so those analog signals need to be transformed into digital signals, and then controlling euipments will be realsied based on different needs, during which it is involved with signal collection and processing.Owing to the fact that many fields need measure different signals such as aircraft, madical treatment etc. and need receive and process many kinds of signals, it requires multi-channel and multi-rate signal transportation research, because different signals need different receiving time and the signal receiving rate may be different. In this thesis, the research for multi-channel and multi-rate signal tansportation is finished based on data-collection system. Now the data collection system needs more signals and their types also become more, so it nees multui-channel and multi-rate technologies. The current digital system is developing towards large volume, small size and high speed. FPGA has such advantages as highly integrating, lower energy-consuming and can put these functions: collecting, controlling, dealing, transporting into a small chip. FPGA follows such trend of technological development, so it can be widely used.The thesis concentrates on the collected relative signals and their transportations during the process of studying four channels. The data collection system can use three means: MCU, DSP and FPGA. MCU can be used to control, because it must carry out the program based on the order. What’s worse, it can only be used to collect small data. If DSP is used to finish the collection of multi-channel data, more DSPs are needed to realise synchronous acquisition, which leads to the increament of the cost and the system’s complexity. However, FPGA can realise paralle processing and sequential processing. By using FPGA’s parallel processing, we propose an avilable method of synchronous acquisition and processing which is based on FPGA’s high speed, multi-channel and multi-rate.In this system, most peocessing are based on extracting and interpolation by using a filter to achieve the exchange of data sampling rate by using input and output data from FPGA’S IP Core’s asynchronous FIFO cache. During this course, sampling for the input data is various and flexible. However, when the data comes into FPGA, the encoding system will automatially recognise the length of the data, and by some algorithm, it will realise extracting and interpolation or their combination in order to acheive the suitable length of sample rate what the peocessing system needs. Multi-channel FPGA will independently dealing these multi-channel data and they will interfer with each other which increase the system’s stablity. In the same time, each channel’s interior will divide one channel’s signal into two parts which will improve processing speed and these dealing information is from the serial port.By exploration, simulation and debug, the system can work well. After 24 hours’ s testing, this system can gunction for a long time. By designing and debuging, we come to the conclusion: the system using 4 channel parallel processing highly improves the data processing speed and the efficiency. By using multi-rate signal processing system, we realise the high precision of system. At the same time, the work place is also expanded and its stability will be improved.