Study On Technology Of Sine-Like Signal Communication

The development of intelligent oil drilling technology depends on logging while drilling (LWD) technology. But the data transfer rate bottleneck and lack of energy of underground mine equipment restricts the development of the LWD and even the whole drilling technical. For the status of drilling technology, the topic focuses on improving the data transmission speed and the supply of underground power, with universal significance and wide applications.This paper studies the communications technology based on the principle of sine-like. The definition and basic principles of the sine-like modulation are introduced. Its time-domain waveform and spectrum are simulated, and the important parameters of the function formula are selected. The main advantage is analyzed in detail that one code element can be represented with 1 waveform cycle only and the signal carrier frequency is the bit rate of the information sent. Compared with other carrier means that one code element is shown with a dozen or several dozen waveform cycles, the data transmission speed is improved greatly. The requirement of real-time and high-speed data transmission can be satisfied. To highlight the sine-like characteristics, the waveform is further optimized, so the bandwidth becomes narrower, and the superposition noise is less, and also receiver filter design is more convenient. When the signal frequency is high, the sine-like modulation is difficult. So it is instead with the square waves of different duty, but the modulation parameter is unchanging.On the basis of the theory and simulation, the modulation and demodulation method is deep studied. This paper discusses the communication programs of the two channels that the power transmission line and magnetic induction transmission channel. The power line digital modem hardware and signal coupling circuit is designed with DSP as the core processing chip. However, coupling device design is difficult, so another channel is attempted. The magnetic induction transmission modem circuit is designed with CPLD as the processing chip, and the communication systems are built and tested for the two projects.The results of the communication experiment show that the data transmission method in this paper is reliable. The speed of the system is up to 600kbps with low bit- error rates.