Study on the Real-Time Lossless Data Compression Method Used in the Readout System for Micropattern Gas Detector

Nowadays, the data compression technique is fully developed and widely used in many fields, such as communication, multi-media, image processing, and so on. In large physics experiments, especially the ones with micropattern gas detectors (MPGDs), there are always large numbers of readout channels and many data to be transferred. However, the data compression technique is seldom applied in this field. In this paper, a real-time lossless data compression method, which can reduce the data transmission bandwidth while keeping all information of data is proposed and successfully implemented in a general-purpose MPGD readout system. The compression method discussed in this paper mainly consists of two steps: The first step is to preprocess the data according to the signal characteristics and the second step is to compress the preprocessed data using a common lossless compression algorithm. In addition, the whole compression method is implemented in the field-programmable gate array (FPGA) and can run in real time. The compression method is validated with two different signals and the compression ratios reach 43% and 30%, respectively.