Wireless Communication for Drilling Using Acoustic Wave Based on MIMO-OFDM

Underground data transmission methods are divided into wired and wireless. Wired transmission includes traditional cable and optical fiber. Wireless transmission includes pressure wave and electromagnetic wave. The limitation of the down-hole data upload rate has become the bottleneck. The wireless transmission system of an acoustic wave using a drilling fluid channel is studied. Drilling fluid channel is a multi-path channel with frequency selective fading characteristics. In the process of drilling, the shape of drill string is spatial spiral bending. This paper provides an exhaustive research in OFDM-MIMO for drilling acoustic telemetry system. The characteristics of drilling fluid channel are discussed. The performances of multiple input multiple output (MIMO), multiple input single output (MISO) and single input single output (SISO) wireless acoustic transmission systems are compared. Acoustic waves transmitted along the drilling fluid channel can realize underground wireless communication with a high transmission rate and a low bit error rate.