Abstract:
Systems and methods for creating and using a conditioning signal are provided. In some embodiments, systems for creating a conditioning signal providing information regarding an input signal are provided, wherein the systems comprise: a signal conditioning developer that receives the input signal and produces the conditioning signal; a delay device that receives the input signal and produces a delayed input signal, wherein the delayed input signal is delayed to simultaneously transmit with the conditioning signal and form a vector signal with the delayed input signal and the conditioning signal; and a receiving circuit coupled to the signal conditioning developer and the delay device that receives the vector signal and dynamically adjusts according to the conditioning signal.

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS  
       [0001]     This application claims benefit of U.S. Provisional Patent Application No. 60/728,677, filed Oct. 19, 2005, which is hereby incorporated by reference herein in its entirety. 
     
    
     TECHNICAL FIELD  
       [0002]     The disclosed subject matter relates to systems and methods for creating and using a conditioning signal.  
       BACKGROUND  
       [0003]     Signals are widely used to represent and carry information. Signals are typically propagated in a medium, such as an electrical charge in a wire or radio waves in the air. Signals generally come in two forms, digital signals and analog signals. Digital signals are discrete and quantized, while analog signals are continuous. Both of these types of signals may be modified by using devices such as amplifiers, filters, and signal processors. These devices can change the amplitude of a signal or some frequencies of a signal. Devices such as analog-to-digital (A/D) converters and digital-to-analog (D/A) converters change a signal from being analog to digital and vice versa. Typically, to perform this conversion, the signal is measured at time instants, which is usually referred to as sampling, and then assigned a discrete value after a comparison is performed.  
       SUMMARY  
       [0004]     The disclosed subject matter relates to systems and methods for creating and using a conditioning signal. In some embodiments, systems for creating a conditioning signal providing information regarding an input signal are provided, wherein the systems comprise: a signal conditioning developer that receives the input signal and produces the conditioning signal; a delay device that receives the input signal and produces a delayed input signal, wherein the delayed input signal is delayed to simultaneously transmit with the conditioning signal and form a vector signal with the delayed input signal and the conditioning signal; and a receiving circuit coupled to the signal conditioning developer and the delay device that receives the vector signal and dynamically adjusts according to the conditioning signal.  
         [0005]     In some embodiments, methods for creating and using a conditioning signal providing information regarding an input signal are provided, wherein the methods comprise: deriving from an input signal a conditioning signal that contains information regarding how a receiving circuit is to handle the input signal; delaying the input signal to synchronize the input signal with the conditioning signal where a delayed input signal and the conditioning signal form a vector signal; transmitting the vector signal to the receiving circuit; and adjusting the receiving circuit dynamically according to the conditioning signal.  
         [0006]     In some embodiments, systems for creating and using a conditioning signal providing information regarding an input signal are provided, wherein the systems comprise: a means for providing a signal conditioning developer that receives the input signal and produces the conditioning signal; a means for providing a delay that receives the input signal and produces a delayed input signal that is delayed to simultaneously transmit with the conditioning signal and form a vector signal with the delayed input signal and the conditioning signal; and a means for providing a receiving circuit coupled to the means for providing a signal conditioning developer and the means for providing a delay device that receives the vector signal and dynamically adjusts according to the conditioning signal.  
         [0007]     In some embodiments, systems for creating and using a conditioning signal providing information regarding an input signal are provided, wherein the systems comprise: a signal conditioning developer that receives the input signal and produces the conditioning signal that is transmitted simultaneously with the input signal to form a vector signal; and a receiving circuit coupled to the signal conditioning developer that receives the vector signal and dynamically adjusts according to the conditioning signal. 
     
    
     BRIEF DESCRIPTION OF THE DRAWINGS  
       [0008]      FIG. 1  is a schematic diagram of a signal developer in accordance with some embodiments of the disclosed subject matter;  
         [0009]      FIG. 2  is a schematic diagram of digital signal conditioning in accordance with some embodiments of the disclosed subject matter;  
         [0010]      FIG. 3  is an illustration of a stored word in accordance with some embodiments of the disclosed subject matter;  
         [0011]      FIG. 4  is an illustration of digitizing in accordance with some embodiments of the disclosed subject matter;  
         [0012]      FIG. 5  is an illustration of a signal range in accordance with some embodiments of the disclosed subject matter;  
         [0013]      FIG. 6A  is an illustration of a signal;  
         [0014]      FIG. 6B  is an illustration of a signal and a conditioning signal, together forming a vector in accordance with some embodiments of the disclosed subject matter; and 
     
    
     DETAILED DESCRIPTION  
       [0015]     Systems and methods for creating a conditioning signal are provided. In some embodiments, a conditioning signal is created from an input signal and possibly other information, such as preset settings or system variables. The conditioning signal can provide information relating to this input signal to a circuit so that a circuit receiving the conditioning signal can dynamically adapt to the input signal. The conditioning signal can be used to provide a variety of information about the input signal such as necessary range to accommodate the signal, the acceptable distortion level for the signal, and the tolerance of the signal to noise.  
         [0016]     Signal processors and circuits are typically designed to accommodate a range of signals expected plus some safety factor. Many times, a difficulty arises in designing a circuit to both function over the expected range and to remain precise when handling signals that operate within a fraction of the expected range.  FIG. 5  is an illustration of a signal range  514 . Signal  510  varies in voltage over time, but is typically between 0.1 volt and 2 volts. Circuits that are designed to process signal  510  may need to handle a signal range from 0 volts to 2 volts in order to avoid distortion or loss of information. The circuits may be over-designed as far as processing of other, less demanding signals--for example, a signal whose range is 0.5 volts to 1.5 volts, are concerned. The circuits can also be over-designed with respect to one parameter, but sacrifice performance in terms of another parameter. For example, to provide a circuit whose range is 0 volts to 2 volts, the circuit&#39;s signal-to-noise ratio may be degraded over a frequency range such as 100 Hz to 1.5 KHz. In general, circuits cannot be designed optimally for all the types of signals that can be received.  
         [0017]     A solution to this problem, in some embodiments, is to provide a conditioning signal with the input signal. This conditioning signal, which synchronously accompanies the input signal, provides information regarding how the input signal can be processed. Further, the conditioning signal can specify how the circuit is to handle the signal (i.e., the circuit may be conditioned for some levels of performance). For example, the conditioning signal can provide information such as an amplitude  512  or an signal range  514  of signal  510  to the receiving circuit. This information from the conditioning signal can be used to dynamically establish a point of operation in the circuit for achieving some types of conditions such as setting the amount of power dissipated, the tolerance for noise in the signal, the desired frequency response, and/or the tolerance for distortion. The conditioning signal can also contain instructions regarding what level of service the circuit should maintain for some types of conditions.  
         [0018]     A classical representation of a signal  610  x(t) is illustrated in  FIG. 6A . Signal  610  x(t) has a value that can vary as a function of time.  FIG. 6B  illustrates a signal  612  and a conditioning signal  614  in accordance with some embodiments of the disclosed subject matter. Signal  612  and conditioning signal  614  are represented by a pair {x(t), C x (t)} as a vector signal. In some embodiments, C x (t) is the envelope of x(t), and the envelope is used for the purposes of resizing a signal so that the signal&#39;s envelop is compressed or expanded in the dynamic range. Conditioning signal  614  C x (t) can also be used to adjust a receiving circuit for the purposes of dynamic biasing for low power and low noise. An example of dynamic biasing is adjusting a DC bias level voltage in an amplifier to reduce power dissipation, while avoiding signal clipping or other forms of distortion from degrading signal  612 . In other embodiments, conditioning signal  614  can carry information relating to the acceptable distortion level, or the needed driving ability. An example of an acceptable distortion level can be in a telephony system where the acceptable distortion level is set to the worst level acceptable for a call. By conditioning other components to process a signal allowing for the acceptable level of distortion, so that the call is within the acceptable distortion level when received, one can ensure the signal is not over-processed.  
         [0019]      FIG. 1  is a schematic diagram of a signal developer  100  in accordance with some embodiments of the disclosed subject matter. Signal developer  100  includes a receiving circuit  108 , delay circuit  110 , and a conditioning signal developer  112 . When generating a conditioning signal  114 , C x (t), from a signal  116 , x(t), a delay is added by delay circuit  110  to account for time spent processing or otherwise analyzing signal  116  in conditioning signal developer  112 . Delay is added to signal  116  to keep delayed signal  118  and conditioning signal  114  synchronized. In some embodiments, the delay added may be negligible or zero, in which case the delay circuit  110  can be omitted. Receiving circuit  108  receives conditioning signal  114  and delayed signal  118  and uses conditioning signal  114  to adjust the processing of delayed signal  118 .  
         [0020]     Conditioning signal developer  112  may be implemented using, for example, an envelope detector, a peak detector, an average level detector, or any suitable device that can develop a conditioning signal for the desired application. Additionally, combinations of detectors, such as an envelope detector and an average level detector, can be used in combination to produce a conditioning signal. Delay circuit  110  may be implemented using any suitable mechanism. For example, with analog signals, capacitors may be used to hold an input signal&#39;s value for a period of time in an analog-to-digital converter. As another example, with digital signals, an input signal may be stored in a digital delay circuit, such as a digital buffer, register, or memory.  
         [0021]      FIG. 2  is a schematic diagram of a digital signal conditioning circuit  200  in accordance with some embodiments of the disclosed subject matter. Digital signal conditioning circuit  200  includes a digital delay  210 , a digital-to-analog (D/A) converter  212 , and conditioning signal developer  214 . A digital input signal  216  x(n) is used by conditioning signal developer  214  to develop conditioning signal  218  C x (n). The conditioning signal  218 , in some embodiments, can be provided to D/A converter  212  by line  220  to condition the converter for handling delayed signal  222 . Conditioning signal  218  can also be provided as a digital signal in some embodiments to external devices such as digital signal processors. If the conditioning signal  218  C x (n) and delayed signal  222  x(t-d) are represented by a pair as a digital vector signal, the conditioning information C x (n) can be stored with the delayed signal  222  x(n-m).  
         [0022]     When a signal, such as  216 , is being processed by conditioning signal developer  214 , in some embodiments, present, past, and future values of signal  216  are used to determine information regarding signal  216 . A reproduction engine, for example, D/A converter  212  when connected with line  220 , can be used to interpret conditioning signal  218 . The reproduction engine can use a pre-determined standard, in some embodiments, to modify delayed signal  222 . In some embodiments, the delay and the conditioning signal developer can be under software control or implemented in software.  
         [0023]      FIG. 3  illustrates a digital stored pair  300  in accordance with some embodiments of the disclosed subject matter. Stored pair  300  includes conditioning signal information  310  and signal information  312 . Conditioning signal information  310  is interspersed with signal information  312 , and is provided as a header to signal information  312 , in some embodiments. Conditioning signal information  310  and signal information  312  can be stored together on a CD, DVD, a magnetic film, flash memory, or any computer readable medium. For example, on a CD, with a digital word, a number of bits may be used for signal information  312  x(n-m), and a number of bits may be used for conditioning signal information  310  C x (n).  
         [0024]     The signal information  312  part of stored pair  300  is “what to handle” the conditioning signal information  310  part of stored pair  300  is “how to handle.” In some embodiments, the conditioning signal C x  can be used as a signal to prepare the circuit for upcoming input signal values. Since both conditioning signal information  310  and signal  312  are in stored pair  300 , conditioning signal information  310  can be accessed in conjunction with reading signal information  312  and the two can be re-aligned properly in time so that the conditioning information  310  can be in conjunction with signal information  312 .  
         [0025]     In another example, conditioning signal information  310  C x (n) can include information that specifies how many bits are used to form signal information  312  x(n-m). In some embodiments, conditioning signal information  310  C x (n) can be used to dynamically alter the precision at which a signal is quantized. This may be accomplished by changing the level lines with respect to the signal so that precise measurements can be taken over the range of the signal. This will be explained in more detail below in connection with digitizing.  
         [0026]      FIG. 4  illustrates conditioning signaling in combination with digitizing in accordance with some embodiments of the disclosed subject matter. Input signal  450  shows a signal that can be digitized with a greater degree of precision compared to input signal  452  when level lines  454  are used for digitizing. A conditioning signal can be used with input signal  452 , for example, to resize the signal envelope while the signal is being digitized by a digitizer or dynamically change the digitizer to quantize input signal  452  more precisely. This is shown in  FIG. 4  by additional level lines  456 . In some embodiments, amplitude digitizing can be used. Amplitude digitizing is signal quantization that uses level line thresholds and the time crossed to digitally represent a signal, and is further described in US Patent Publication No. 20040263375, entitled “Continuous-Time Digital Signal Generation, Transmission, Storage and Processing,” which is hereby incorporated by reference herein in its entirety.  
         [0027]     The conditioning signal information can be used to provide a quantized representation that is uses 16 bits, but gives a quantized precision of a 24-bit digitizer, for example. This representation can be stored on a computer readable medium such as a CD or DVD. The conditioning signal information can be used when processing the signal for use, such as playing a song. Input signal  452  can be re-constituted by using the conditioning signal information along with the digitized signal in, for example, the circuitry of a CD player.  
         [0028]     Typically, in CDs, low-amplitude signals are stored using only a few bits because like signal  452 , these low-amplitude signals are not resolved well and experience quantization error. In some embodiments, conditioning signal information can be used to more precisely measure input signal  452 , and the conditioning signal can store information for the receiving circuit to reconstitute input signal  452  from the stored bits which are altered to more precisely measure the signal.  
         [0029]     Although the disclosed subject matter has been described and illustrated in the foregoing exemplary embodiments, it is understood that the present disclosure has been made only by way of example, and that numerous changes in the details of implementation of the disclosed subject matter may be made without departing from the spirit and scope of the disclosed subject matter, which is limited only by the claims which follow.