This White Paper focuses on how the mud-pulse telemetry transmitter sends out blocks of encoded pulses after every flow cycle in the following order:

ErdosMiller-MudPulseTelemetry-Mary-graph

 

For an introduction to M-Ary telemetry, please see the MUD Pulse Telemetry M-ARY Encoding and Decoding white paper by Erdos Miller.

 

Inside the Advanced Mud Pulse Telemetry: M-Ary Encoding for MWD Tools (Chapter 2) White Paper you will find all about:

  • Synch blocks.
  • Survey sequence number blocks.
  • Toolface/Logging Sequence Number Blocks.
  • Data Block Formats.
  • Breaking Binary Data into 2 and 3-bit packets.
  • M-Ary Pulse Encoding (including examples).

 

ErdosMiller_CTA-Download-The-White-Paper

 

About M-Ary Pulse Encoding

M-Ary pulse encoding is a form of phase shift keying. The packets are encoded in 4 TU’s (for 2-bit) or 8 TU’s (for a 3-bit packet). The position of the rising edge of the pulse determines the packet value.

For instance, in a 2-bit packet, the pulse would start at position 0 TU when the packet value is 3, at 1 TU for a value of 2, at 2 TU for a value of 1 and at 3 TU for a value of 0. Note that the pulse width itself is 2 TUs. Each packet is separated from the next packet by 4 TU’s.

Here's an example:

Screen Shot 2021-03-05 at 1.13.57 PM