Key Problem Research On Data Transmission Of Large-scale Seismic Acquision And Recording System

The fusion of sensor, computer, communication and storage technologies greatly accelerates the development of seismic exploration technology, and therefore stimulates the need of geological exploration further. Nowadays, large-scale, full-digitalization and high real-time are the three development trends of current seismic exploration equipment, which make it urgent to improve the real-time ability of data transmission system. Based on the research of channel capacity and reliability of seismic specific cable in Large-scale Seismic Acquisition and Recording System (LSARS), this dissertation analyzes, researches, improves and realizes a low power data transmission system, and consequently provides a theory and experiment foundation for the applications of LSARS. The main contents of this dissertation are described as follows:First, the dissertation analyzes and studies the Inter Symbol Interference (ISI) and the relationship between ISI and frequency in one transmission line, and the interaction between different transmission lines at the same time. Second, because of the full duplex characteristic of LSARS, the general MIMO (Multiple-Input Multiple-Output) model is improved, a new model, i.e. the extended MIMO model, and crosstalk elimination based on it are proposed. Therefore, the Signal-to-Noise Ratio (SNR) and channel capacity are improved, and the transmission power requirement is also reduced.To improve the reliability of data transmission, this dissertation also studies the energy-efficient frame synchronization algorithm and error correction algorithm on 8B/10B modulated channel. According to the characteristic of 8B/10B coding and programmable logic, the inadequate performance of conventional synchronization scheme with single control word on 8B/10B channel is solved by hard decision correlation algorithm and lengthening of synchronization code. The theory analysis and experiment results show that the improved algorithm has lower error synchronization rate, lower complexity and makes the hardware and programmable logic easier to implement. By the serialization of Reformulated inversionless Berlekamp-Massey (RiBM) algorithm of Reed-Solomon (RS) decoder, an Area-efficient RiBM (ARiBM) algorithm and a multiplex decoder based on it are proposed. The improved algorithm solves the problem of high complexity and high power consumption of RiBM decoder, and makes RS code be applied successfully in LSARS. The theory analysis and experiment results show that the improved algorithm meets the requirements of the decoding speed of LSARS, and decreases the decoding complexity significantly.Indoor tests and filed experiments are carried out on the developed data transmission system and relative experiment platform of LSARS. The comparison results with foreign similar equipments show that the data transmission system performs better in the fields of real-time ability, high reliability and low power consumption.