| 主权项 |
1. A method for use with a drill string positioned within a borehole, the method comprising:
receiving, by a receiver, a baseband signal transmitted via vibrations through the drill string using a plurality of elastic waves; oversampling the received baseband signal at the receiver to duplicate a spectrum of the baseband signal a plurality of times, determining whether a single passband of a plurality of available passbands has a predetermined signal to noise ratio and sufficient bandwidth to include an entire spectrum of the baseband signal of one of the plurality of spectrums of the baseband signal created by the oversampling; selecting, by the receiver, if the single passband is available, the single passband from the plurality of passbands that are caused by the reflection of the baseband signal within the drill string based on one of the plurality of passbands having the predetermined signal to noise ratio and sufficient bandwidth to include the entire spectrum of the baseband signal of one of the plurality of spectrums of the baseband signal created by the oversampling, in order to recover the baseband signal from the duplicated spectrum; selecting, by the receiver if the single passband is not available, multiple passbands from the plurality of passbands including different portions of the spectrum of the baseband signal; combining portions of the spectrum of the baseband signal recovered from each of the selected multiple passbands to recover the entire spectrum of the baseband signal, the combination based upon a signal to noise ratio of each of the passbands, such that higher quality passbands contribute more to the combination than the passbands with lower quality signals; and decoding, by the receiver, the baseband signal to recover a bit stream contained within the baseband signal. |
