Patent Publication Number: US-10333588-B2

Title: Communication via a magnio

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS 
     The present application is a divisional of co-pending U.S. patent application Ser. No. 15/003,677 filed Jan. 21, 2016, titled “COMMUNICATION VIA A MAGNIO”, which claims benefit of and priority to U.S. Provisional Patent Application No. 62/261,643 filed Dec. 1, 2015, titled “DIAMOND NITROGEN VACANCY PACKET MAGNETIC RADIO,” both of which are incorporated by reference herein in their entirety. 
    
    
     TECHNICAL FIELD 
     The present disclosure relates, in general, to magnetic communication. More particularly, the present disclosure relates to a diamond nitrogen vacancy magnio. 
     BACKGROUND 
     The following description is provided to assist the understanding of the reader. None of the information provided or references cited is admitted to be prior art. Information can be transmitted over the air using radio waves. For example, information can be coded into bits of 1s and 0s. A radio wave can be modulated in a manner that represents the series of 1s and 0s. A transmitter can receive the radio waves and decode the 1s and 0s to replicate the information. However, communication using radio waves is not perfect. Thus, communicating via alternative methods can be beneficial. 
     SUMMARY 
     An illustrative system includes a transmitting device and a receiving device. The transmitting device may include a first processor configured to transmit data to a transmitter and the transmitter. The transmitter may be configured to transmit the data via a magnetic field. The receiving device may include a magnetometer configured to detect the magnetic field and a second processor configured to decipher the data from the detected magnetic field. 
     An illustrative method includes receiving, at a first processor, data and transmitting, by the transmitter, the data via a magnetic field. The method may also include detecting, by a magnetometer, the magnetic field. The method may further include receiving, by a second processor, an indication of the magnetic field from the magnetometer and deciphering, by the second processor, the data form the indication of the magnetic field. 
     An illustrative device includes a processor and a transmitter. The processor may be configured to receive a stream of data and encode the stream of data into a plurality of streams of data. The transmitter may be configured to receive the plurality of streams of data and transmit the plurality of streams of data simultaneously via a plurality of magnetic fields. Each of the plurality of streams may be transmitted via a corresponding one of the plurality of magnetic fields. 
     An illustrative device includes a magnetometer configured to simultaneously measure the magnitude of a modulated magnetic field in a plurality of directions. The device may further include a processor operatively coupled to the magnetometer. The processor may be configured to receive, from the magnetometer, a time-varying signal corresponding to the modulated magnetic field and determine a plurality of transmission channels based on the time-varying signal. The processor may be further configured to monitor the plurality of transmission channels to determine data transmitted on each of the plurality of transmission channels. 
     The foregoing summary is illustrative only and is not intended to be in any way limiting. In addition to the illustrative aspects, embodiments, and features described above, further aspects, embodiments, and features will become apparent by reference to the following drawings and the detailed description. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIGS. 1A and 1B  are graphs illustrating the frequency response of a DNV sensor in accordance with an illustrative embodiment. 
         FIG. 2A  is a diagram of NV center spin states in accordance with an illustrative embodiment. 
         FIG. 2B  is a graph illustrating the frequency response of a DNV sensor in response to a changed magnetic field in accordance with an illustrative embodiment. 
         FIG. 3  is a block diagram of a magnetic communication system in accordance with an illustrative embodiment. 
         FIGS. 4A and 4B  show the strength of a magnetic field versus frequency in accordance with an illustrative embodiment. 
         FIG. 5  is a block diagram of a computing device in accordance with an illustrative embodiment. 
     
    
    
     The foregoing and other features of the present disclosure will become apparent from the following description and appended claims, taken in conjunction with the accompanying drawings. Understanding that these drawings depict only several embodiments in accordance with the disclosure and are, therefore, not to be considered limiting of its scope, the disclosure will be described with additional specificity and detail through use of the accompanying drawings. 
     DETAILED DESCRIPTION 
     In the following detailed description, reference is made to the accompanying drawings, which form a part hereof. In the drawings, similar symbols typically identify similar components, unless context dictates otherwise. The illustrative embodiments described in the detailed description, drawings, and claims are not meant to be limiting. Other embodiments may be utilized, and other changes may be made, without departing from the spirit or scope of the subject matter presented here. It will be readily understood that the aspects of the present disclosure, as generally described herein, and illustrated in the figures, can be arranged, substituted, combined, and designed in a wide variety of different configurations, all of which are explicitly contemplated and make part of this disclosure. 
     Radio waves can be used as a carrier for information. Thus, a transmitter can modulate radio waves at one location, and a receiver at another location can detect the modulated radio waves and demodulate the signals to receive the information. Many different methods can be used to transmit information via radio waves. However, all such methods use radio waves as a carrier for the information being transmitted. 
     However, radio waves are not well suited for all communication methods. For example, radio waves can be greatly attenuated by some materials. For example, radio waves do not generally travel well through water. Thus, communication through water can be difficult using radio waves. Similarly, radio waves can be greatly attenuated by the earth. Thus, wireless communication through the earth, for example for coal or other mines, can be difficult. It is often difficult to communicate wirelessly via radio waves from a metal enclosure. The strength of a radio wave signal can also be reduced as the radio wave passes through materials such as walls, trees, or other obstacles. Additionally, communication via radio waves is widely used and understood. Thus, secret communication using radio waves requires complex methods and devices to maintain the secrecy of the information. 
     According to some embodiments described herein, wireless communication is achieved without using radio waves as a carrier for information. Rather, modulated magnetic fields can be used to transmit information. For example, a transmitter can include a coil or inductor. When current passes through the coil, a magnetic field is generated around the coil. The current that passes through the coil can be modulated, thereby modulating the magnetic field. Accordingly, information converted into a modulated electrical signal (e.g., the modulated current through the coil) can be used to transfer the information into a magnetic field. A magnetometer can be used to monitor the magnetic field. The modulated magnetic field can, therefore, be converted into traditional electrical systems (e.g., using current to transfer information). Thus, a communications signal can be converted into a magnetic field and a remote receiver (e.g., a magnetometer) can be used to retrieve the communication from the modulated magnetic field. 
     A diamond with a nitrogen vacancy (DNV) can be used to measure a magnetic field. DNV sensors generally have a quick response to magnetic fields, consume little power, and are accurate. Diamonds can be manufactured with nitrogen vacancy (NV) centers in the lattice structure of the diamond. When the NV centers are excited by light, for example green light, and microwave radiation, the NV centers emit light of a different frequency than the excitation light. For example, green light can be used to excite the NV centers, and red light can be emitted from the NV centers. When a magnetic field is applied to the NV centers, the frequency of the light emitted from the NV centers changes. Additionally, when the magnetic field is applied to the NV centers, the frequency of the microwaves at which the NV centers are excited changes. Thus, by shining a green light (or any other suitable color) through a DNV and monitoring the light emitted from the DNV and the frequencies of microwave radiation that excite the NV centers, a magnetic field can be monitored. 
     NV centers in a diamond are oriented in one of four spin states. Each spin state can be in a positive direction or a negative direction. The NV centers of one spin state do not respond the same to a magnetic field as the NV centers of another spin state. A magnetic field vector has a magnitude and a direction. Depending upon the direction of the magnetic field at the diamond (and the NV centers), some of the NV centers will be excited by the magnetic field more than others based on the spin state of the NV centers. 
       FIGS. 1A and 1B  are graphs illustrating the frequency response of a DNV sensor in accordance with an illustrative embodiment.  FIGS. 1A and 1B  are meant to be illustrative only and not meant to be limiting.  FIGS. 1A and 1B  plot the frequency of the microwaves applied to a DNV sensor on the x-axis versus the amount of light of a particular frequency (e.g., red) emitted from the diamond.  FIG. 1A  is the frequency response of the DNV sensor with no magnetic field applied to the diamond, and  FIG. 1B  is the frequency response of the DNV sensor with a seventy gauss (G) magnetic field applied to the diamond. 
     As shown in  FIG. 1A , when no magnetic field is applied to the DNV sensor, there are two notches in the frequency response. With no magnetic field applied to the DNV sensor, the spin states are not resolvable. That is, with no magnetic field, the NV centers with various spin states are equally excited and emit light of the same frequency. The two notches shown in  FIG. 1A  are the result of the positive and negative spin directions. The frequency of the two notches is the axial zero field splitting parameter. 
     When a magnetic field is applied to the DNV sensor, the spin states become resolvable in the frequency response. Depending upon the excitation by the magnetic field of NV centers of a particular spin state, the notches corresponding to the positive and negative directions separate on the frequency response graph. As shown in  FIG. 1B , when a magnetic field is applied to the DNV sensor, eight notches appear on the graph. The eight notches are four pairs of corresponding notches. For each pair of notches, one notch corresponds to a positive spin state and one notch corresponds to a negative spin state. Each pair of notches corresponds to one of the four spin states of the NV centers. The amount by which the pairs of notches deviate from the axial zero field splitting parameter is dependent upon how strongly the magnetic field excites the NV centers of the corresponding spin states. 
     As mentioned above, the magnetic field at a point can be characterized with a magnitude and a direction. By varying the magnitude of the magnetic field, all of the NV centers will be similarly affected. Using the graph of  FIG. 1A  as an example, the ratio of the distance from 2.87 GHz of one pair to another will remain the same when the magnitude of the magnetic field is altered. As the magnitude is increased, each of the notch pairs will move away from 2.87 GHz at a constant rate, although each pair will move at a different rate than the other pairs. 
     When the direction of the magnetic field is altered, however, the pairs of notches do not move in a similar manner to one another.  FIG. 2A  is a diagram of NV center spin states in accordance with an illustrative embodiment.  FIG. 2A  conceptually illustrates the four spin states of the NV centers. The spin states are labeled NV A, NV B, NV C, and NV D. Vector  201  is a representation of a first magnetic field vector with respect to the spin states, and Vector  202  is a representation of a second magnetic field vector with respect to the spin states. Vector  201  and vector  202  have the same magnitude, but differ in direction. Accordingly, based on the change in direction, the various spin states will be affected differently depending upon the direction of the spin states. 
       FIG. 2B  is a graph illustrating the frequency response of a DNV sensor in response to a changed magnetic field in accordance with an illustrative embodiment. The frequency response graph illustrates the frequency response of the DNV sensor from the magnetic field corresponding to vector  201  and to vector  202 . As shown in  FIG. 2B , the notches corresponding to the NV A and NV D spin states moved closer to the axial zero field splitting parameter from vector  201  to vector  202 , the negative (e.g., lower frequency notch) notch of the NV C spin state moved away from the axial zero field splitting parameter, the positive (e.g., high frequency notch) of the NV C spin state stayed essentially the same, and the notches corresponding to the NV B spin state increased in frequency (e.g., moved to the right in the graph). Thus, by monitoring the changes in frequency response of the notches, the DNV sensor can determine the direction of the magnetic field. 
     Additionally, magnetic fields of different directions can be modulated simultaneously and each of the modulations can be differentiated or identified by the DNV sensor. For example, a magnetic field in the direction of NV A can be modulated with a first pattern, a magnetic field in the direction of NV B can be modulated with a second pattern, a magnetic field in the direction of NV C can be modulated with a third pattern, and a magnetic field in the direction of NV D can be modulated with a fourth pattern. The movement of the notches in the frequency response corresponding to the various spin states can be monitored to determine each of the four patterns. 
     However, in some embodiments, the direction of the magnetic field corresponding to the various spin states of a DNV sensor of a receiver may not be known by the transmitter. In such embodiments, by monitoring at least three of the spin states, messages transmitted on two magnetic fields that are orthogonal to one another can be deciphered. Similarly, by monitoring the frequency response of the four spin states, messages transmitted on three magnetic fields that are orthogonal to one another can be deciphered. Thus, in some embodiments, two or three independent signals can be transmitted simultaneously to a receiver that receives and deciphers the two or three signals. Such embodiments can be a multiple-input multiple-output (MIMO) system. Diversity in the polarization of the magnetic field channels provides a full rank channel matrix even through traditionally keyhole channels. In an illustrative embodiment, a full rank channel matrix allows MIMO techniques to leverage all degrees of freedom (e.g., three degrees of polarization). Using a magnetic field to transmit information circumvents the keyhole effect that propagating a radio frequency field can have. 
       FIG. 3  is a block diagram of a magnetic communication system in accordance with an illustrative embodiment. An illustrative magnio system  300  includes input data  305 , a  310 , a transmitter  345 , a modulated magnetic field  350 , a magnetometer  355 , a magnio receiver  360 , and output data  395 . In alternative embodiments, additional, fewer, and/or different elements may be used. 
     In an illustrative embodiment, input data  305  is input into the magnio system  300 , transmitted wirelessly, and the output data  395  is generated at a location remote from the generation of the input data  305 . In an illustrative embodiment, the input data  305  and the output data  395  contain the same information. 
     In an illustrative embodiment, input data  305  is sent to the magnio transmitter  310 . The magnio transmitter  310  can prepare the information received in the input data  305  for transmission. For example, the magnio transmitter  310  can encode or encrypt the information in the input data  305 . The magnio transmitter  310  can send the information to the transmitter  345 . 
     The transmitter  345  is configured to transmit the information received from the magnio transmitter  310  via one or more magnetic fields. The transmitter  345  can be configured to transmit the information on one, two, three, or four magnetic fields. That is, the transmitter  345  can transmit information via a magnetic field oriented in a first direction, transmit information via a magnetic field oriented in a second direction, transmit information via a magnetic field oriented in a third direction, and/or transmit information via a magnetic field oriented in a fourth direction. In some embodiments in which the transmitter  345  transmits information via two or three magnetic fields, the magnetic fields can be orthogonal to one another. In alternative embodiments, the magnetic fields are not orthogonal to one another. 
     The transmitter  345  can be any suitable device configured to create a modulated magnetic field. For example, the transmitter  345  can include one or more coils. Each coil can be a conductor wound around a central axis. For example, in embodiments in which the information is transmitted via three magnetic fields, the transmitter  345  can include three coils. The central axis of each coil can be orthogonal to the central axis of the other coils. 
     The transmitter  345  generates the modulated magnetic field  350 . The magnetometer  355  can detect the modulated magnetic field  350 . The magnetometer  355  can be located remotely from the transmitter  345 . For example, with a current of about ten Amperes through a coil (e.g., the transmitter) and with a magnetometer magnetometer  355  with a sensitivity of about one hundred nano-Tesla, a message can be sent, received, and recovered in full with several meters between the transmitter and receiver and with the magnetometer magnetometer  355  inside of a Faraday cage. The magnetometer  355  can be configured to measure the modulated magnetic field  350  along three or four directions. As discussed above, a magnetometer  355  using a DNV sensor can measure the magnetic field along four directions associated with four spin states. The magnetometer  355  can transmit information, such as frequency response information, to the magnio receiver  360 . 
     The magnio receiver  360  can analyze the information received from the magnetometer  355  and decipher the information in the signals. The magnio receiver  360  can reconstitute the information contained in the input data  305  to produce the output data  395 . 
     In an illustrative embodiment, the magnio transmitter  310  includes a data packet generator  315 , an outer encoder  320 , an interleaver  325 , an inner encoder  330 , an interleaver  335 , and an output packet generator  340 . In alternative embodiments, additional, fewer, and/or different elements may be used. The various components of the magnio transmitter  310  are illustrated in  FIG. 3  as individual components and are meant to be illustrative only. However, in alternative embodiments, the various components may be combined. Additionally, the use of arrows is not meant to be limiting with respect to the order or flow of operations or information. Any of the components of the magnio transmitter  310  can be implemented using hardware and/or software. 
     The input data  305  can be sent to the data packet generator  315 . In an illustrative embodiment, the input data  305  is a series or stream of bits. The data packet generator  315  can break up the stream of bits into packets of information. The packets can be any suitable size. In an illustrative embodiment, the data packet generator  315  includes appending a header to the packets that includes transmission management information. In an illustrative embodiment the header can include information used for error detection, such as a checksum. Any suitable header may be used. In some embodiments, the input data  305  is not broken into packets. 
     The stream of data generated by the data packet generator  315  can be sent to the outer encoder  320 . The outer encoder  320  can encrypt or encode the stream using any suitable cypher or code. Any suitable type of encryption can be used such as symmetric key encryption. In an illustrative embodiment, the encryption key is stored on memory associated with the magnio transmitter  310 . In an illustrative embodiment, the magnio transmitter  310  may not include the outer encoder  320 . For example, the messages may not be encrypted. In an illustrative embodiment, the outer encoder  320  separates the stream into multiple channels. In an illustrative embodiment, the outer encoder outer encoder  320  performs forward error correction (FEC). In some embodiments, the forward error correction dramatically increases the reliability of transmissions for a given power level. 
     In an illustrative embodiment, the encoded stream from the outer encoder  320  is sent to the interleaver  325 . In an illustrative embodiment, the interleaver  325  interleaves bits within each packet of the stream of data. In such an embodiment, each packet has the same bits, but the bits are shuffled according to a predetermined pattern. Any suitable interleaving method can be used. In an alternative embodiment, the packets are interleaved. In such an embodiment, the packets are shuffled according to a predetermined pattern. In some embodiments, the magnio transmitter  310  may not include the interleaver  325 . 
     In some embodiments, interleaving data can be used to prevent loss of a sequence of data. For example, if a stream of bits are in sequential order and there is a communication loss during a portion of the stream, there is a relatively large gap in the information corresponding to the lost bits. However, if the bits were interleaved (e.g., shuffled), once the stream is de-interleaved (e.g., unshuffled) at the receiver, the lost bits are not grouped together but are spread across the sequential bits. In some instances, if the lost bits are spread across the message, error correction can be more successful in determining what the lost bits were supposed to be. 
     In an illustrative embodiment, the interleaved stream from the interleaver  325  is sent to the inner encoder  330 . The inner encoder  330  can encrypt or encode the stream using any suitable cypher or code. Any suitable type of encryption can be used such as symmetric key encryption. In an illustrative embodiment, the encryption key is stored on memory associated with the magnio transmitter  310 . In an illustrative embodiment, the magnio transmitter  310  may not include the inner encoder  330 . In an illustrative embodiment, the inner encoder  330  and the outer encoder  320  perform different functions. For example, the inner encoder  330  can use a deep convolutional code and can perform most of the forward error correction, and the outer encoder can be used to correct residual errors and can use a different coding technique from the inner encoder  330  (e.g., a block-parity based encoding technique). 
     In an illustrative embodiment, the encoded stream from the inner encoder  330  is sent to the interleaver  335 . In an illustrative embodiment, the interleaver  335  interleaves bits within each packet of the stream of data. In such an embodiment, each packet has the same bits, but the bits are shuffled according to a predetermined pattern. Any suitable interleaving method can be used. In an alternative embodiment, the packets are interleaved. In such an embodiments, the packets are shuffled according to a predetermined pattern. In an illustrative embodiment, interleaving the data spreads out burst-like errors across the signal, thereby facilitating the decoding of the message. In some embodiment, the magnio transmitter  310  may not include the interleaver  335 . 
     In an illustrative embodiment, the interleaved stream from the interleaver  335  is sent to the output packet generator  340 . The output packet generator  340  can generate the packets that will be transmitted. For example, the output packet generator  340  may append a header to the packets that includes transmission management information. In an illustrative embodiment the header can include information used for error detection, such as a checksum. Any suitable header may be used. 
     In an illustrative embodiment, the output packet generator  340  appends a synchronization sequence to each of the packets. For example, a synchronization sequence can be added to the beginning of each packet. The packets can be transmitted on multiple channels. In such an embodiment, each channel is associated with a unique synchronization sequence. The synchronization sequence can be used to decipher the channels from one another, as is discussed in greater detail below with regard to the magnio receiver  360 . 
     In an illustrative embodiment, the output packet generator  340  modulates the waveform to be transmitted. Any suitable modulation can be used. In an illustrative embodiment, the waveform is modulated digitally. In some embodiments, minimum shift keying can be used to modulate the waveform. For example, non-differential minimum shift key can be used. In an illustrative embodiment, the waveform has a continuous phase. That is, the waveform does not have phase discontinuities. In an illustrative embodiment, the waveform is sinusoidal in nature. 
     In an illustrative embodiment, the modulated waveform is sent to the transmitter  345 . In an illustrative embodiment, multiple modulated waveforms are sent to the transmitter  345 . As mentioned above, two, three, or four signals can be transmitted simultaneously via magnetic fields with different directions. In an illustrative embodiment, three modulated waveforms are sent to the transmitter  345 . Each of the waveforms can be used to modulate a magnetic field, and each of the magnetic fields can be orthogonal to one another. 
     The transmitter  345  can use the received waveforms to produce the modulated magnetic field  350 . The modulated magnetic field  350  can be a combination of multiple magnetic fields of different directions. The frequency used to modulate the modulated magnetic field  350  can be any suitable frequency. In an illustrative embodiment, the carrier frequency of the modulated magnetic field  350  can be 10 kHz. In alternative embodiments, the carrier frequency of the modulated magnetic field  350  can be less than or greater than 10 kHz. In some embodiments, the carrier frequency can be modulated to plus or minus the carrier frequency. That is, using the example in which the carrier frequency is 10 kHz, the carrier frequency can be modulated down to 0 Hz and up to 20 kHz. In alternative embodiments, any suitable frequency band can be used. 
       FIGS. 4A and 4B  show the strength of a magnetic field versus frequency in accordance with an illustrative embodiment.  FIGS. 4A and 4B  are meant to be illustrative only and not meant to be limiting. In some instances, the magnetic spectrum is relatively noisy. As shown in  FIG. 4A , the noise over a large band (e.g., 0-200 kHz) is relatively high. Thus, communicating over such a large band may be difficult.  FIG. 4B  illustrates the noise over a smaller band (e.g., 1-3 kHz). As shown in  FIG. 4B , the noise over a smaller band is relatively low. Thus, modulating the magnetic field across a smaller band of frequencies can be less noisy and more effective. In an illustrative embodiment, the magnio transmitter  310  can monitor the magnetic field and determine a suitable frequency to modulate the magnetic fields to reduce noise. That is, the magnio transmitter  310  can find a frequency that has a high signal to noise ratio. In an illustrative embodiment, the magnio transmitter  310  determines a frequency band that has noise that is below a predetermined threshold. 
     In an illustrative embodiment, the magnio receiver  360  includes the demodulator  365 , the de-interleaver  370 , the soft inner decoder  375 , the de-interleaver  380 , the outer decoder  385 , and the output data generator  390 . In alternative embodiments, additional, fewer, and/or different elements may be used. For example, the magnio receiver  360  can include the magnetometer  355  in some embodiments. The various components of the magnio receiver  360  are illustrated in  FIG. 3  as individual components and are meant to be illustrative only. However, in alternative embodiments, the various components may be combined. Additionally, the use of arrows is not meant to be limiting with respect to the order or flow of operations or information. Any of the components of the magnio receiver  360  can be implemented using hardware and/or software. 
     The magnetometer  355  is configured to measure the modulated magnetic field  350 . In an illustrative embodiment, the magnetometer  355  includes a DNV sensor. The magnetometer  355  can monitor the modulated magnetic field  350  in up to four directions. As illustrated in  FIG. 2A , the magnetometer  355  can be configured to measure the magnetometer  355  in one or more of four directions that are tetrahedronally arranged. As mentioned above, the magnetometer  355  can monitor n+1 directions where n is the number of channels that the transmitter  345  transmits on. For example, the transmitter  345  can transmit on three channels, and the magnetometer  355  can monitor four directions. In an alternative embodiment, the transmitter  345  can transmit via the same number of channels (e.g., four) as directions that the magnetometer  355  monitors. 
     The magnetometer  355  can send information regarding the modulated magnetic field  350  to the demodulator  365 . The demodulator  365  can analyze the received information and determine the direction of the magnetic fields that were used to create the modulated magnetic field  350 . That is, the demodulator  365  can determine the directions of the channels that the transmitter  345  transmitted on. As mentioned above, the transmitter  345  can transmit multiple streams of data, and each stream of data is transmitted on one channel. Each of the streams of data can be preceded by a unique synchronization sequence. In an illustrative embodiment, the synchronization sequence includes 1023 bits. In alternative embodiments, the synchronization sequence includes more than or fewer than 1023 bits. Each of the streams can be transmitted simultaneously such that each of the channels are time-aligned with one another. The demodulator  365  can monitor the magnetic field in multiple directions simultaneously. Based on the synchronization sequence, which is known to the magnio receiver  360 , the demodulator  365  can determine the directions corresponding to the channels of the transmitter  345 . When the streams of synchronization sequences are time-aligned, the demodulator  365  can monitor the modulated magnetic field  350  to determine how the multiple channels mixed. Once the demodulator  365  determines how the various channels are mixed, the channels can be demodulated. 
     For example, the transmitter  345  transmits on three channels, with each channel corresponding to an orthogonal direction. Each channel is used to transmit a stream of information. For purposes of the example, the channels are named “channel A,” “channel B,” and “channel C.” The magnetometer  355  monitors the modulated magnetic field  350  in four directions. The demodulator  365  can monitor for three signals in orthogonal directions. For purposes of the example, the signals can be named “signal  1 ,” “signal  2 ,” and “signal  3 .” Each of the signals can contain a unique, predetermined synchronization sequence. The demodulator  365  can monitor the modulated magnetic field  350  for the signals to be transmitted on the channels. There is a finite number of possible combinations that the signals can be received at the magnetometer  355 . For example, signal  1  can be transmitted in a direction corresponding to channel A, signal  2  can be transmitted in a direction corresponding to channel B, and signal  3  can be transmitted in a direction corresponding to channel C. In another example, signal  2  can be transmitted in a direction corresponding to channel A, signal  3  can be transmitted in a direction corresponding to channel B, and signal  1  can be transmitted in a direction corresponding to channel C, etc. The modulated magnetic field  350  of the synchronization sequence for each of the possible combinations that the signals can be received at the magnetometer  355  can be known by the demodulator  365 . The demodulator  365  can monitor the output of the magnetometer  355  for each of the possible combinations. Thus, when one of the possible combinations is recognized by the demodulator  365 , the demodulator  365  can monitor for additional data in directions associated with the recognized combination. In another example, the transmitter  345  transmits on two channels, and the magnetometer  355  monitors the modulated magnetic field  350  in three directions. 
     The demodulated signals (e.g., the received streams of data from each of the channels) is sent to the de-interleaver  370 . The de-interleaver  370  can undo the interleaving of the interleaver  335 . The de-interleaved streams of data can be sent to the soft inner decoder  375 , which can undo the encoding of the inner encoder  330 . Any suitable decoding method can be used. For example, in an illustrative embodiment the inner encoder  330  uses a three-way, soft-decision turbo decoding function. In an alternative embodiment, a two-way, soft-decision turbo decoding function may be used. For example, the expected cluster positions for signal levels are learned by the magnio receiver  360  during the synchronization portion of the transmission. When the payload/data portion of the transmission is processed by the magnio receiver  360 , distances from all possible signal clusters to the observed signal value are computed for every bit position. The bits in each bit position are determined by combining the distances with state transition probabilities to find the best path through a “trellis.” The path through the trellis can be used to determine the most likely bits that were communicated. 
     The decoded stream can be transmitted to the de-interleaver  380 . The de-interleaver  380  can undo the interleaving of the interleaver  325 . The de-interleaved stream can be sent to the outer decoder  385 . In an illustrative embodiment, the outer decoder  385  undoes the encoding of the outer encoder  320 . The unencoded stream of information can be sent to the output data generator  390 . In an illustrative embodiment, the output data generator  390  undoes the packet generation of data packet generator  315  to produce the output data  395 . 
       FIG. 5  is a block diagram of a computing device in accordance with an illustrative embodiment. An illustrative computing device  500  includes a memory  510 , a processor  505 , a transceiver  515 , a user interface  520 , and a power source  525 . In alternative embodiments, additional, fewer, and/or different elements may be used. The computing device  500  can be any suitable device described herein. For example, the computing device  500  can be a desktop computer, a laptop computer, a smartphone, a specialized computing device, etc. The computing device  500  can be used to implement one or more of the methods described herein. 
     In an illustrative embodiment, the memory  510  is an electronic holding place or storage for information so that the information can be accessed by the processor  505 . The memory  510  can include, but is not limited to, any type of random access memory (RAM), any type of read only memory (ROM), any type of flash memory, etc. such as magnetic storage devices (e.g., hard disk, floppy disk, magnetic strips, etc.), optical disks (e.g., compact disk (CD), digital versatile disk (DVD), etc.), smart cards, flash memory devices, etc. The computing device  500  may have one or more computer-readable media that use the same or a different memory media technology. The computing device  500  may have one or more drives that support the loading of a memory medium such as a CD, a DVD, a flash memory card, etc. 
     In an illustrative embodiment, the processor  505  executes instructions. The instructions may be carried out by a special purpose computer, logic circuits, or hardware circuits. The processor  505  may be implemented in hardware, firmware, software, or any combination thereof. The term “execution” is, for example, the process of running an application or the carrying out of the operation called for by an instruction. The instructions may be written using one or more programming language, scripting language, assembly language, etc. The processor  505  executes an instruction, meaning that it performs the operations called for by that instruction. The processor  505  operably couples with the user interface  520 , the transceiver  515 , the memory  510 , etc. to receive, to send, and to process information and to control the operations of the computing device  500 . The processor  505  may retrieve a set of instructions from a permanent memory device such as a ROM device and copy the instructions in an executable form to a temporary memory device that is generally some form of RAM. An illustrative computing device  500  may include a plurality of processors that use the same or a different processing technology. In an illustrative embodiment, the instructions may be stored in memory  510 . 
     In an illustrative embodiment, the transceiver  515  is configured to receive and/or transmit information. In some embodiments, the transceiver  515  communicates information via a wired connection, such as an Ethernet connection, one or more twisted pair wires, coaxial cables, fiber optic cables, etc. In some embodiments, the transceiver  515  communicates information via a wireless connection using microwaves, infrared waves, radio waves, spread spectrum technologies, satellites, etc. The transceiver  515  can be configured to communicate with another device using cellular networks, local area networks, wide area networks, the Internet, etc. In some embodiments, one or more of the elements of the computing device  500  communicate via wired or wireless communications. In some embodiments, the transceiver  515  provides an interface for presenting information from the computing device  500  to external systems, users, or memory. For example, the transceiver  515  may include an interface to a display, a printer, a speaker, etc. In an illustrative embodiment, the transceiver  515  may also include alarm/indicator lights, a network interface, a disk drive, a computer memory device, etc. In an illustrative embodiment, the transceiver  515  can receive information from external systems, users, memory, etc. 
     In an illustrative embodiment, the user interface  520  is configured to receive and/or provide information from/to a user. The user interface  520  can be any suitable user interface. The user interface  520  can be an interface for receiving user input and/or machine instructions for entry into the computing device  500 . The user interface  520  may use various input technologies including, but not limited to, a keyboard, a stylus and/or touch screen, a mouse, a track ball, a keypad, a microphone, voice recognition, motion recognition, disk drives, remote controllers, input ports, one or more buttons, dials, joysticks, etc. to allow an external source, such as a user, to enter information into the computing device  500 . The user interface  520  can be used to navigate menus, adjust options, adjust settings, adjust display, etc. 
     The user interface  520  can be configured to provide an interface for presenting information from the computing device  500  to external systems, users, memory, etc. For example, the user interface  520  can include an interface for a display, a printer, a speaker, alarm/indicator lights, a network interface, a disk drive, a computer memory device, etc. The user interface  520  can include a color display, a cathode-ray tube (CRT), a liquid crystal display (LCD), a plasma display, an organic light-emitting diode (OLED) display, etc. 
     In an illustrative embodiment, the power source  525  is configured to provide electrical power to one or more elements of the computing device  500 . In some embodiments, the power source  525  includes an alternating power source, such as available line voltage (e.g., 120 Volts alternating current at 60 Hertz in the United States). The power source  525  can include one or more transformers, rectifiers, etc. to convert electrical power into power useable by the one or more elements of the computing device  500 , such as 1.5 Volts, 8 Volts, 12 Volts, 24 Volts, etc. The power source  525  can include one or more batteries. 
     In an illustrative embodiment, any of the operations described herein can be implemented at least in part as computer-readable instructions stored on a computer-readable memory. Upon execution of the computer-readable instructions by a processor, the computer-readable instructions can cause a node to perform the operations. 
     The herein described subject matter sometimes illustrates different components contained within, or connected with, different other components. It is to be understood that such depicted architectures are merely exemplary, and that in fact many other architectures can be implemented which achieve the same functionality. In a conceptual sense, any arrangement of components to achieve the same functionality is effectively “associated” such that the desired functionality is achieved. Hence, any two components herein combined to achieve a particular functionality can be seen as “associated with” each other such that the desired functionality is achieved, irrespective of architectures or intermedial components. Likewise, any two components so associated can also be viewed as being “operably connected,” or “operably coupled,” to each other to achieve the desired functionality, and any two components capable of being so associated can also be viewed as being “operably couplable,” to each other to achieve the desired functionality. Specific examples of operably couplable include but are not limited to physically mateable and/or physically interacting components and/or wirelessly interactable and/or wirelessly interacting components and/or logically interacting and/or logically interactable components. 
     With respect to the use of substantially any plural and/or singular terms herein, those having skill in the art can translate from the plural to the singular and/or from the singular to the plural as is appropriate to the context and/or application. The various singular/plural permutations may be expressly set forth herein for sake of clarity. 
     It will be understood by those within the art that, in general, terms used herein, and especially in the appended claims (e.g., bodies of the appended claims) are generally intended as “open” terms (e.g., the term “including” should be interpreted as “including but not limited to,” the term “having” should be interpreted as “having at least,” the term “includes” should be interpreted as “includes but is not limited to,” etc.). It will be further understood by those within the art that if a specific number of an introduced claim recitation is intended, such an intent will be explicitly recited in the claim, and in the absence of such recitation no such intent is present. For example, as an aid to understanding, the following appended claims may contain usage of the introductory phrases “at least one” and “one or more” to introduce claim recitations. However, the use of such phrases should not be construed to imply that the introduction of a claim recitation by the indefinite articles “a” or “an” limits any particular claim containing such introduced claim recitation to inventions containing only one such recitation, even when the same claim includes the introductory phrases “one or more” or “at least one” and indefinite articles such as “a” or “an” (e.g., “a” and/or “an” should typically be interpreted to mean “at least one” or “one or more”); the same holds true for the use of definite articles used to introduce claim recitations. In addition, even if a specific number of an introduced claim recitation is explicitly recited, those skilled in the art will recognize that such recitation should typically be interpreted to mean at least the recited number (e.g., the bare recitation of “two recitations,” without other modifiers, typically means at least two recitations, or two or more recitations). Furthermore, in those instances where a convention analogous to “at least one of A, B, and C, etc.” is used, in general such a construction is intended in the sense one having skill in the art would understand the convention (e.g., “a system having at least one of A, B, and C” would include but not be limited to systems that have A alone, B alone, C alone, A and B together, A and C together, B and C together, and/or A, B, and C together, etc.). In those instances where a convention analogous to “at least one of A, B, or C, etc.” is used, in general such a construction is intended in the sense one having skill in the art would understand the convention (e.g., “a system having at least one of A, B, or C” would include but not be limited to systems that have A alone, B alone, C alone, A and B together, A and C together, B and C together, and/or A, B, and C together, etc.). It will be further understood by those within the art that virtually any disjunctive word and/or phrase presenting two or more alternative terms, whether in the description, claims, or drawings, should be understood to contemplate the possibilities of including one of the terms, either of the terms, or both terms. For example, the phrase “A or B” will be understood to include the possibilities of “A” or “B” or “A and B.” Further, unless otherwise noted, the use of the words “approximate,” “about,” “around,” “substantially,” etc., mean plus or minus ten percent. 
     The foregoing description of illustrative embodiments has been presented for purposes of illustration and of description. It is not intended to be exhaustive or limiting with respect to the precise form disclosed, and modifications and variations are possible in light of the above teachings or may be acquired from practice of the disclosed embodiments. It is intended that the scope of the invention be defined by the claims appended hereto and their equivalents.