Online compressiong and reconstruction of nuclear power plant signals using wavelet transform

Abstract

Many measurement signals are produced from nuclear power plants. We need huge storage to store these needful signals. So we consider signal compressions to reduce storage than saving raw signals. Classical signal compressions are combined lossy compression like Discrete Cosine Transform (DCT) and lossless compression like Huffman coding. In this paper we introduce wavelet transform instead of using DCT and expand this method to online compression. Wavelet transform is a series expansion of signal in wavelet and scaling functions. If a signal is transformed, the signal content is divided into two parts, high and low frequency part. For reducing information, we use threshold concept after transform. For online compression, we use the best time partitioning concept. This wavelet compression method has very high compression ratio without serious signal distortion. It is verified by tests. It will be a useful method when we add Huffman coding for saving in storage and modify the signal recieving part. The cost for saving signals may be reduced using this method.