Device and method for improved data transfer

Abstract

A device that can reduce the effects of interference on an electromagnetic field emitted from a buried, underground or otherwise inaccessible object is provided. The device generates quality metrics relating to a plurality of sideband signals from one or more input signals, compares the quality metrics and selects one or more sideband signals, dependent on the respective quality metrics. A method of selecting one of a plurality of sideband signals using quality metrics is also disclosed.

1 . A signal interference reduction system for reducing the effects of magnetic interference in an electromagnetic field from a buried or inaccessible object, comprising: 
 at least one receiving means for receiving at least one input signal, each input signal comprising a plurality of sideband signals;    determining means for determining a plurality of quality metrics for the plurality of sideband signals;    comparison means for comparing the determined quality metrics; and    output means for selectively outputting at least one sideband signal dependent on the compared quality metrics.    
     
     
         2 . The system as in  claim 1 , further comprising demodulating means for demodulating the plurality of sideband signals of said at least one input signal.  
     
     
         3 . The system as in  claim 2 , wherein the demodulating means for demodulating the double sideband signal comprises a phase locked loop demodulator.  
     
     
         4 . The system as in  claim 2 , wherein the demodulating means for demodulating each single sideband signal are Hilbert transformer demodulators.  
     
     
         5 . The system as in  claim 1 , further comprising selecting means for selecting a number of the plurality of sideband signals of said at least one input signal for comparison.  
     
     
         6 . The system as in  claim 5 , wherein the selecting means is arranged to select sideband signals from a group containing upper, lower and double sideband signals of a single input signal.  
     
     
         7 . The system according to  claim 5 , wherein the selecting means is arranged to select sideband signals from a group containing upper, lower and double sideband signals of a plurality of input signals.  
     
     
         8 . The system as in  claim 1 , wherein the output means is arranged to output said at least one sideband signal with a highest quality metric.  
     
     
         9 . The system as in  claim 1 , wherein the determining means is arranged to determine at least one quality metric by measuring the ratio between the peak and RMS voltages of a respective sideband signal of said at least one input signal.  
     
     
         10 . The system as in  claim 1 , wherein the determining means is arranged to determine at least one quality metric by measuring the bit error rate of a respective sideband signal.  
     
     
         11 . The system as in  claim 1 , wherein the determining means is arranged to determine at least one quality metric by measuring modulation of the bit width of a respective sideband signal.  
     
     
         12 . The system as in  claim 1 , wherein the determining means and the comparison means comprise a processor.  
     
     
         13 . A method of reducing effects of magnetic interference in an electromagnetic field from a buried or inaccessible object, the method comprising: 
 receiving at least one input signal, each input signal comprising a plurality of sideband signals;    determining a plurality of quality metrics for the plurality of sidebands signals;    comparing the determined quality metrics; and    selectively outputting a sideband signal dependent on the comparison of the quality metrics.    
     
     
         14 . A method as in  claim 13 , further comprising selecting a number of the plurality of sideband signals of said at least one input signal to be compared.  
     
     
         15 . A method as in  claim 13 , wherein the sideband signals of the at least one input signal are chosen from a group containing upper, lower and double sideband signals of a single input signal.  
     
     
         16 . A method as in  claim 13 , wherein the sideband signals of the at least one input signal are chosen from a group containing upper, lower and double sideband signals of a plurality of input signals.  
     
     
         17 . A method as in  claim 13 , wherein the sideband signal with a highest quality metric is output.  
     
     
         18 . A method as in  claim 13 , wherein at least one quality metric is determined by measuring the ratio between the peak and RMS values of a respective sideband signal.  
     
     
         19 . A method as in  claim 13 , wherein at least one quality metric is determined by measuring the bit error rate of a respective sideband signal.  
     
     
         20 . A method as in  claim 13 , wherein at least one quality metric is determined by measuring the bit width modulation of a respective sideband signal.  
     
     
         21 . A method as in  claim 13 , wherein the method is carried out by a processor.  
     
     
         22 . A signal interference reduction device for reducing the effects of magnetic interference in an electromagnetic field from a buried or inaccessible object, the device comprising: 
 a receiver to receive at least one input signal, each input signal comprising a plurality of sideband signals;    a processor connected to the receiver to determine a plurality of quality metrics for the plurality of sideband signals, and to compare the determined quality metrics; and    an output device connected to the processor to selectively output one or more sideband signals dependent on the compared quality metrics.    
     
     
         23 . The device as in  claim 22 , further comprising a plurality of demodulators connected to the receiver to demodulate the plurality of sideband signals.  
     
     
         24 . The device as in  claim 22 , wherein one of the demodulators is a phase locked loop demodulator.  
     
     
         25 . The device as in  claim 23 , wherein one of the demodulators is a phase locked loop demodulator.  
     
     
         26 . The device as in  claim 22 , wherein one of the demodulators is a Hilbert transformer, demodulator to demodulate a single sideband signal.  
     
     
         27 . A device according to  claim 25 , further comprising a further Hilbert transformer demodulator to demodulate a further single sideband signal.  
     
     
         28 . A device as in  claim 22 , wherein the processor is adapted to select a number of the plurality of sideband signals in said at least one input signal for comparison.  
     
     
         29 . The device as in  claim 28 , wherein the processor is adapted to select sideband signals from a group containing upper, lower and double sideband signals of a single input signal.  
     
     
         30 . The device as in  claim 28 , wherein the processor is arranged to select sideband signals from a group containing upper, lower and double sideband signals of a plurality of input signals.  
     
     
         31 . The device as in  claim 22 , wherein the output device is arranged to output the sideband signal of said at least one input signal with a highest quality metric.  
     
     
         32 . The device as in  claim 22 , wherein the processor is adapted to determine at least one quality metric by measuring the ratio between the peak and RMS voltages of a respective sideband signal.  
     
     
         33 . The device as in  claim 22 , wherein the processor is adapted to determine at least one quality metric by measuring the bit error rate of a respective sideband signal.  
     
     
         34 . The device as in  claim 23 , wherein the processor is adapted to determine at least one quality metric by measuring modulation of the bit width of a respective sideband signal.