Frequency hopping sounder signal for channel mapping and equalizer initialization
First Claim
1. A method performed by a drilling system in a drilling operation, the method comprising:
- identifying, by the drilling system, a frequency range for sounding a communication path between a first device at a first location within a wellbore and a second device at a second location within the wellbore;
generating a sounding signal being continuous in time and non-contiguous in frequency with the second device by;
assigning a center frequency, a bandwidth, and a timeframe to each of a plurality of sounding sequences, such that an entirety of the frequency range is assigned to the plurality of sounding sequences, and wherein the bandwidths assigned to at least two of the plurality of sounding sequences are configured to overlap, andplaying the plurality of sounding sequences in order according to the timeframe assigned to each sounding sequence in the plurality of sounding sequences;
transmitting the sounding signal through the communication path to produce an attenuated sounding signal;
receiving, at the first device, the attenuated sounding signal;
comparing, by the drilling system, the attenuated sounding signal to the sounding signal, to yield a comparison, wherein the comparison is used to estimate a transfer function for channel mapping and to initialize an equalizer to reduce distortion effect of frequency selective fading in the drilling operation; and
estimating, by the drilling system, the transfer function of the communication path based on the comparison.
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Accused Products
Abstract
A system for channel sounding and initializing an equalizer using a frequency hopping sounder signal. The system identifies a frequency range for sounding a channel between a first device at a first location within a wellbore and a second device at a second location within the wellbore. Center frequencies, bandwidths, and timeframes are assigned to each of a plurality of sounding sequences, such that an entirety of the frequency range is assigned to the plurality of sounding sequences, and wherein when played in order according to the timeframe assigned to each sounding sequence in the plurality of sounding sequences, a sounding signal having a non-contiguous frequency is produced. By comparing an attenuated sounding signal based on the sounding signal to the sounding signal, the system estimates a transfer function of the channel. The system also initializes the equalizer based on the comparison.
24 Citations
23 Claims
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1. A method performed by a drilling system in a drilling operation, the method comprising:
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identifying, by the drilling system, a frequency range for sounding a communication path between a first device at a first location within a wellbore and a second device at a second location within the wellbore; generating a sounding signal being continuous in time and non-contiguous in frequency with the second device by; assigning a center frequency, a bandwidth, and a timeframe to each of a plurality of sounding sequences, such that an entirety of the frequency range is assigned to the plurality of sounding sequences, and wherein the bandwidths assigned to at least two of the plurality of sounding sequences are configured to overlap, and playing the plurality of sounding sequences in order according to the timeframe assigned to each sounding sequence in the plurality of sounding sequences; transmitting the sounding signal through the communication path to produce an attenuated sounding signal; receiving, at the first device, the attenuated sounding signal; comparing, by the drilling system, the attenuated sounding signal to the sounding signal, to yield a comparison, wherein the comparison is used to estimate a transfer function for channel mapping and to initialize an equalizer to reduce distortion effect of frequency selective fading in the drilling operation; and estimating, by the drilling system, the transfer function of the communication path based on the comparison. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10, 11)
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12. A drilling system used in a drilling operation, the drilling system comprising:
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a processor; and a non-transitory computer-readable storage medium having instructions stored which, when executed by the processor, cause the processor to perform operations comprising; identifying a frequency range for sounding a communication path between a first device at a first location within a wellbore and a second device at a second location within the wellbore; generating a sounding signal being continuous in time and non-contiguous in frequency with the second device by; assigning a center frequency, a bandwidth, and a timeframe to each of a plurality of sounding sequences, such that an entirety of the frequency range is assigned to the plurality of sounding sequences, and wherein the bandwidths assigned to at least two of the plurality of sounding sequences are configured to overlap, and playing the plurality of sounding sequences in order according to the timeframe assigned to each sounding sequence in the plurality of sounding sequences; transmitting the sounding signal through the communication path to produce an attenuated sounding signal; receiving, at the first device, the attenuated sounding signal;
comparing the attenuated sounding signal to the sounding signal, to yield a comparison, wherein the comparison is used to estimate a transfer function for channel mapping and to initialize an equalizer to reduce distortion effect of frequency selective fading in the drilling operation; andestimating the transfer function of the communication path based on the comparison. - View Dependent Claims (13, 14, 15, 16, 17, 18, 19, 20, 21)
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22. A non-transitory computer-readable storage device having instructions stored which, when executed by a computing device in a drilling operation, cause the computing device to perform operations comprising:
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identifying a frequency range for sounding a communication path between a first device at a first location within a wellbore and a second device at a second location within the wellbore; generating a sounding signal being continuous in time and non-contiguous in frequency with the second device by; assigning a center frequency, a bandwidth, and a timeframe to each of a plurality of sounding sequences, such that an entirety of the frequency range is assigned to the plurality of sounding sequences, and wherein the bandwidths assigned to at least two of the plurality of sounding sequences are configured to overlap, and playing the plurality of sounding sequences in order according to the timeframe assigned to each sounding sequence in the plurality of sounding sequences;
transmitting the sounding signal through the communication path to produce an attenuated sounding signal;receiving, at the first device, the attenuated sounding signal; comparing the attenuated sounding signal to the sounding signal, to yield a comparison, wherein the comparison is used to estimate a transfer function for channel mapping and to initialize an equalizer to reduce distortion effect of frequency selective fading in the drilling operation; and estimating the transfer function of the communication path based on the comparison. - View Dependent Claims (23)
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Specification