Research And FPGA Design Of Terrane Communication System Based On M-ary Spread Spectrum

UTC (Underground Terrane Communication) plays a very important role in many kinds of rescue missions. Especially in coal mine disasters, for transferring emergent, efficient and actual information about mineworkers’security, its responsibility can never be substituted. Focus on the deficiencies, such as short propagation distance and worse anti-interference performance, of existing emergent system, this thesis proposed a new UWB terrane communication system based on impulse wave-forming technique. The main researches and innovations of this thesis can be summarized as follows:1. Based on the deep analysis of M-ary spread spectrum and RS (Reed-Solomon) coding techniques, a scheme of terrane communication system combined with M-ary double orthogonal spread spectrum and RS code techniques is designed. The contents which this system transfers are audio and short message data. Different technique parameters are chosen for different requirements on reliability by audio and short message communications. Simulation results show that the SNRs of audio and short message communication schemes are-12dB and-29dB when the BER (bit error ratio) is10-3.2. A new signaling format, consisting of3bits, is designed to indicate the communication contents, beginning and ending of the contents. The design is prone to establish and disconnect the communication channel. Moreover, the signaling is designed with differential coding technique, and so it can rid the influence caused by180degree phase confusion. Simulation results show that the signaling acquisition probability reaches95%in the case of Eb/N0=7dB.3. Designs a new impulse waveform. The waveform has characteristics of low Duty Ratio, high PAPR (Peak to Average Power Ratio), great instantaneous power and strong drive capability, which adapt the electromagnetic wave to the complex channel properties in underground terrane medium.4. Designs the FPGA modules for transmitter and receiver, including M-ary double orthogonal spread spectrum, RS coding, wave-forming and signaling sending modules at the transmitter and match filter, signaling capture, de-spread spectrum and RS decoding modules at the receiver. What’s more, the functional simulation and timing simulation of each module are implemented.5. Completes part of the FPGA modules’ test work both transmitter and receiver, and verifies the function of each module.