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1. (WO2017062009) MUD PULSE TELEMETRY PREAMBLE FOR SEQUENCE DETECTION AND CHANNEL ESTIMATION

Pub. No.:    WO/2017/062009    International Application No.:    PCT/US2015/054667
Publication Date: Fri Apr 14 01:59:59 CEST 2017 International Filing Date: Fri Oct 09 01:59:59 CEST 2015
IPC: E21B 47/12
E21B 47/18
Applicants: HALLIBURTON ENERGY SERVICES INC.
Inventors: BARAK, Ehud
Title: MUD PULSE TELEMETRY PREAMBLE FOR SEQUENCE DETECTION AND CHANNEL ESTIMATION
Abstract:
A method and system of mud pulse telemetry uses a preamble having a number of periods of a synchronization sequence followed by a single period of a channel estimation sequence. The synchronization may be characterized by a generally flat frequency spectrum, and the channel estimation sequence may be characterized by a low cross-correlation with said synchronization sequence. The sequences may be generated from a set of nonrepeating discrete sequences. The preamble may be suitable for both sequence detection and channel estimation, satisfy all the physical and/or electronic constraints of the system, and allow for fast convergence of an adaptive channel tracking or equalization system.