Pattern recognition-based decoding method for the negative pulsed downlink signal with a narrow pulse width

Abstract The negative pulsed downlink communication system is used to send surface control commands the downhole rotary steering tool at thousands of meters, which a significant part current technology. At present, transmission efficiency very low, and only simple can be transmitted in few minutes, limits development technology with complex functions. To improve rate system, pulse width needs shortened. However, due influence signal characteristics, waveform narrow will severely distorted, increases difficulty decoding signal. Therefore, method based on pattern recognition for proposed this paper, establishes Euclidean distance matrix model between similar characteristic segments rising or falling edge signal, coding timing among segment each analyzed, instruction are achieved, solves problem large deviation threshold method. experimental results show that paper achieve accurate 6 s Compared method, it seen accuracy greatly improved, smaller width, more advantage.