用于MWD遥传系统的联合编码调制方法

Joint Coding and Modulation Method for MWD Telemetry

遥传技术是随钻测量(MWD,measurement while drilling)系统中的一项关键技术,目前大多数MWD系统均采用泥浆脉冲方式进行数据传输。随着井深的增加,单纯的脉冲调制的传输性能会快速恶化。提出了一种联合卷积编码与脉冲间隔调制,构造出一种网格编码脉冲间隔调制(TC-PIM)方法。TC-PIM最大化调制输出序列之间的最小时间距离,从而获得显著的编码增益。TC-PIM可以用于随钻测量系统,以提高泥浆脉冲遥传系统的传输距离。

The telemetry technology is a key technology of measurement while drilling（MWD）,and at present,the mud pulse is used for most of the MWD telemetry system.The transmission performance of the simple pulse modulation will deteriorate rapidly with the increase of the well depth.A joint convolution coding and pulse interval modulation is presented,so the trellis coded pulse interval modulation（TC-PIM） is constructed.The TCPIM maximizes the minimal time distance between the modulation output sequences,and gets the significant coding gain.The TC-PIM can be applied to measurement while drilling system to extend the transmission distance of the mud pulse telemetry system.