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Analytic signal

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102: 1759: 1209: 1127: 654: 1754:{\displaystyle {\begin{aligned}s_{\mathrm {a} }(t)&\triangleq {\mathcal {F}}^{-1}\\&={\mathcal {F}}^{-1}\\&=\underbrace {{\mathcal {F}}^{-1}\{S(f)\}} _{s(t)}+\overbrace {\underbrace {{\mathcal {F}}^{-1}\{\operatorname {sgn}(f)\}} _{j{\frac {1}{\pi t}}}*\underbrace {{\mathcal {F}}^{-1}\{S(f)\}} _{s(t)}} ^{\text{convolution}}\\&=s(t)+j\underbrace {\left} _{\operatorname {\mathcal {H}} }\\&=s(t)+j{\hat {s}}(t),\end{aligned}}} 3749: 3331: 5739: 808: 359: 2782: 3065: 3733: 1122:{\displaystyle {\begin{aligned}S(f)&={\begin{cases}{\frac {1}{2}}S_{\mathrm {a} }(f),&{\text{for}}\ f>0,\\S_{\mathrm {a} }(f),&{\text{for}}\ f=0,\\{\frac {1}{2}}S_{\mathrm {a} }(-f)^{*},&{\text{for}}\ f<0\ {\text{(Hermitian symmetry)}}\end{cases}}\\&={\frac {1}{2}}.\end{aligned}}} 649:{\displaystyle {\begin{aligned}S_{\mathrm {a} }(f)&\triangleq {\begin{cases}2S(f),&{\text{for}}\ f>0,\\S(f),&{\text{for}}\ f=0,\\0,&{\text{for}}\ f<0\end{cases}}\\&=\underbrace {2\operatorname {u} (f)} _{1+\operatorname {sgn}(f)}S(f)=S(f)+\operatorname {sgn}(f)S(f),\end{aligned}}} 81:
of such a spectrum. These negative frequency components can be discarded with no loss of information, provided one is willing to deal with a complex-valued function instead. That makes certain attributes of the function more accessible and facilitates the derivation of modulation and demodulation
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with real coefficients can excise the portion of interest. Another motive is to reduce the highest frequency, which reduces the minimum rate for alias-free sampling. A frequency shift does not undermine the mathematical tractability of the complex signal representation. So in that sense, the
4435: 2537: 3054: 3326:{\displaystyle s_{\mathrm {a} }(t)={\begin{cases}e^{j(\omega t+\theta )}\ \ =\ e^{j|\omega |t}\cdot e^{j\theta },&{\text{if}}\ \omega >0,\\e^{-j(\omega t+\theta )}=\ e^{j|\omega |t}\cdot e^{-j\theta },&{\text{if}}\ \omega <0.\end{cases}}} 4899: 3527: 4252:
The instantaneous amplitude, and the instantaneous phase and frequency are in some applications used to measure and detect local features of the signal. Another application of the analytic representation of a signal relates to demodulation of
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The concept of analytic signal is well-defined for signals of a single variable which typically is time. For signals of two or more variables, an analytic signal can be defined in different ways, and two approaches are presented below.
2142: 4272: 5383:. The analytic signal is then produced by removing all negative frequencies and multiply the result by 2, in accordance to the procedure described for the case of one-variable signals. However, there is no particular direction for 2898: 5082: 2777:{\displaystyle {\begin{aligned}{\hat {s}}(t)&=\cos \left(\omega t-{\frac {\pi }{2}}\right)=\sin(\omega t),\\s_{\mathrm {a} }(t)&=s(t)+j{\hat {s}}(t)=\cos(\omega t)+j\sin(\omega t)=e^{j\omega t}.\end{aligned}}} 5381: 4742:
has no positive frequencies. In that case, extracting the real component restores them, but in reverse order; the low-frequency components are now high ones and vice versa. This can be used to demodulate a type of
3848: 1834: 3926: 4168: 4246: 5205: 4740: 3532: 2542: 1214: 813: 364: 69:, comprising the original function and its Hilbert transform. This representation facilitates many mathematical manipulations. The basic idea is that the negative frequency components of the 4005: 4792: 2918: 2904:
component, and doubling the positive frequency component. And the analytic representation of a sum of sinusoids is the sum of the analytic representations of the individual sinusoids.
5439: 5410: 5316: 3408:. But it might not be a reversible representation, because the original spectrum is not symmetrical in general. So except for this example, the general discussion assumes real-valued 2382: 2215: 2308: 730: 1985: 692: 5338: 4693: 2500: 4608:. However, restoring the real-valued representation is no longer a simple matter of just extracting the real component. Up-conversion may be required, and if the signal has been 4086: 3489: 3377: 2434: 2265: 1201: 3728:{\displaystyle {\begin{aligned}{\hat {s}}(t)&=je^{-j\omega t},\\s_{\mathrm {a} }(t)&=e^{-j\omega t}+j^{2}e^{-j\omega t}=e^{-j\omega t}-e^{-j\omega t}=0.\end{aligned}}} 279: 5640:
B. Boashash, "Notes on the use of the Wigner distribution for time frequency signal analysis", IEEE Trans. on Acoustics, Speech, and Signal Processing, vol. 26, no. 9, 1987
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restores the suppressed positive frequency components. Another viewpoint is that the imaginary component in either case is a term that subtracts frequency components from
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B. Boashash, "Estimating and Interpreting the Instantaneous Frequency of a Signal-Part I: Fundamentals", Proceedings of the IEEE, Vol. 80, No. 4, pp. 519–538, April 1992
5255: 4961: 318: 5453:, as it is defined for one-variable signals. However, the monogenic signal can be extended to arbitrary number of variables in a straightforward manner, producing an 5104: 5257:
as defined above is interpreted as a time-dependent generalization of the complex amplitude. Their relationship is not unlike that in the real-valued case: varying
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Smith, J.O. "Analytic Signals and Hilbert Transform Filters", in Mathematics of the Discrete Fourier Transform (DFT) with Audio Applications, Second Edition,
2798: 5450: 89:), the conversion from complex back to real is just a matter of discarding the imaginary part. The analytic representation is a generalization of the 4430:{\displaystyle {s_{\mathrm {a} }}_{\downarrow }(t)\triangleq s_{\mathrm {a} }(t)e^{-j\omega _{0}t}=s_{\mathrm {m} }(t)e^{j(\phi (t)-\omega _{0}t)},} 93:
concept: while the phasor is restricted to time-invariant amplitude, phase, and frequency, the analytic signal allows for time-variable parameters.
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A straightforward generalization of the analytic signal can be done for a multi-dimensional signal once it is established what is meant by
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In general, the analytic representation of a simple sinusoid is obtained by expressing it in terms of complex-exponentials, discarding the
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This is another example of using the Hilbert transform method to remove negative frequency components. Nothing prevents us from computing
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Analytic signals are often shifted in frequency (down-converted) toward 0 Hz, possibly creating negative frequency components:
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In the field of time-frequency signal processing, it was shown that the analytic signal was needed in the definition of the
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components.  The real and imaginary parts of an analytic signal are real-valued functions related to each other by the
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The real and imaginary parts of the analytic signal correspond to the two elements of the vector-valued
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A function in blue and the magnitude of its analytic representation in red, showing the envelope effect.
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this can also be expressed as a filtering operation that directly removes negative frequency components
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As long as the manipulated function has no negative frequency components (that is, it is still
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which must be chosen unless there are some additional constraints. Therefore, the choice of
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and phase (or frequency) modulation, and effectively demodulates certain kinds of signals.
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so that the method can have the desirable properties needed for practical applications.
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operator removes the subtraction, giving the appearance of adding new components.
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https://www.dsprelated.com/freebooks/mdft/Analytic_Signals_Hilbert_Transform.html
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is selected to be somewhere in the middle of the desired passband. Then a simple
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can be chosen to minimize the mean square error in linearly approximating the
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Justice, J. (1979-12-01). "Analytic signal processing in music computation".
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https://ccrma.stanford.edu/~jos/r320/Analytic_Signals_Hilbert_Transform.html
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Sometimes the phrase "complex envelope" is given the simpler meaning of the
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Here we use Euler's formula to identify and discard the negative frequency.
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Time-Frequency Signal Analysis and Processing: A Comprehensive Reference
4478:. The complex envelope is not unique; it is determined by the choice of 5376:{\displaystyle {\boldsymbol {\xi }}\cdot {\boldsymbol {\hat {u}}}<0} 4617: 4254: 5262: 3843:{\displaystyle s_{\mathrm {a} }(t)=s_{\mathrm {m} }(t)e^{j\phi (t)},} 2792: 1829:{\displaystyle {\hat {s}}(t)\triangleq \operatorname {\mathcal {H}} } 773:. And the operation is reversible, due to the Hermitian symmetry of 5479: 5221:
of a (constant-frequency) phasor; other times the complex envelope
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Extensions of the analytic signal to signals of multiple variables
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Other choices of reference frequency are sometimes considered:
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Multi-dimensional analytic signal based on an ad hoc direction
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is the real value denoting frequency), then the transform has
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IEEE Transactions on Acoustics, Speech, and Signal Processing
4257:. The polar coordinates conveniently separate the effects of 4180: 4163:{\displaystyle \omega (t)\triangleq {\frac {d\phi }{dt}}(t).} 4241:{\displaystyle f(t)\triangleq {\frac {1}{2\pi }}\omega (t).} 3853:
where the following time-variant quantities are introduced:
5534:"the complex envelope (or complex amplitude)", p. 586 3748: 3319: 1027: 516: 5680:
Encyclopedia of Optical Engineering: Abe-Las, pages 1-1024
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Practical considerations for computing Hilbert transforms
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which may seem counter-intuitive. The complex conjugate
77:) of a real-valued function are superfluous, due to the 5800:, vol. II, Cambridge University Press, Cambridge, 2009. 2801: 5418: 5389: 5346: 5324: 5318:
in the Fourier domain and label any frequency vector
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In the accompanying diagram, the blue curve depicts
3743: 4735:{\displaystyle {s_{\mathrm {a} }}_{\downarrow }(t)} 5433: 5404: 5375: 5332: 5310: 5249: 5199: 5098: 5076: 4955: 4922: 4893: 4781: 4734: 4687: 4646: 4591: 4557: 4530: 4497: 4456: 4429: 4240: 4162: 4080: 4042: 3999: 3920: 3842: 3727: 3509: 3483: 3429: 3400: 3371: 3325: 3048: 2892: 2776: 2520: 2494: 2428: 2408: 2376: 2302: 2259: 2209: 2136: 1979: 1909: 1883: 1861: 1828: 1753: 1195: 1157: 1121: 794: 765: 724: 686: 648: 345: 312: 273: 213: 183: 163: 130: 5571:, online book, 2007 edition, accessed 2021-04-29. 5425: 5396: 5361: 5302: 5286:for this case. This can be done by introducing a 3965: 2314:the negative frequency components. And therefore 5824: 5650:Hlawatsch, Franz; Auger, François (2013-03-01). 2147: 4654:is chosen larger than the highest frequency of 4505:. This concept is often used when dealing with 4000:{\displaystyle \phi (t)\triangleq \arg \!\left} 5818:Analytic Signals and Hilbert Transform Filters 5649: 105:Transfer function to create an analytic signal 5525:"the complex envelope (or complex amplitude)" 4467:This function goes by various names, such as 4464:is an arbitrary reference angular frequency. 4264: 4050:and the red curve depicts the corresponding 3756:An analytic signal can also be expressed in 2126: 2108: 1552: 1537: 1483: 1465: 1413: 1398: 5579: 5577: 5793:, Prentice Hall, Upper Saddle River, 1995. 5585:The Fourier Transform and Its Applications 5776:Learn how and when to remove this message 5187: 5086:or another alternative (for some optimum 5067: 4881: 5676: 5574: 5434:{\displaystyle {\boldsymbol {\hat {u}}}} 5405:{\displaystyle {\boldsymbol {\hat {u}}}} 5311:{\displaystyle {\boldsymbol {\hat {u}}}} 3747: 2377:{\displaystyle s(t)=\operatorname {Re} } 2210:{\displaystyle s(t)=\operatorname {Re} } 100: 5703: 5605: 5444: 5422: 5393: 5358: 5348: 5326: 5299: 2303:{\displaystyle s_{\mathrm {a} }^{*}(t)} 5825: 725:{\displaystyle \operatorname {sgn}(f)} 1980:{\displaystyle s(t)=s(t)*\delta (t),} 687:{\displaystyle \operatorname {u} (f)} 82:techniques, such as single-sideband. 16:Particular representation of a signal 5732: 5441:is ad hoc, or application specific. 5333:{\displaystyle {\boldsymbol {\xi }}} 4688:{\displaystyle s_{\mathrm {a} }(t),} 2495:{\displaystyle s(t)=\cos(\omega t),} 1165:is the inverse Fourier transform of 4620:) might also be necessary to avoid 4081:{\displaystyle s_{\mathrm {m} }(t)} 3484:{\displaystyle s(t)=e^{-j\omega t}} 3372:{\displaystyle s_{\mathrm {a} }(t)} 2429:{\displaystyle \operatorname {Re} } 2260:{\displaystyle \operatorname {Im} } 1196:{\displaystyle S_{\mathrm {a} }(f)} 13: 5728: 5677:Driggers, Ronald G. (2003-01-01). 5129: 5121: 5040: 4986: 4978: 4854: 4809: 4710: 4667: 4365: 4315: 4284: 4063: 3977: 3898: 3869: 3800: 3776: 3598: 3354: 3075: 2642: 2351: 2280: 2239: 2189: 2094: 2006: 1800: 1667: 1523: 1451: 1384: 1302: 1271: 1248: 1223: 1178: 1084: 1060: 969: 909: 859: 669: 537: 373: 14: 5854: 5811: 5807:, Elsevier Science, Oxford, 2003. 5707:Global Environment Remote Sensing 4095:instantaneous phase has units of 3744:Instantaneous amplitude and phase 5737: 5704:Okamoto, KenĘĽichi (2001-01-01). 5587:. McGraw-Hill, 2000. pp. 361-362 142:function with Fourier transform 5697: 5537: 5490: 4604:down-converted signal is still 4101:instantaneous angular frequency 274:{\displaystyle S(-f)=S(f)^{*},} 5670: 5643: 5634: 5599: 5590: 5557: 5528: 5519: 5244: 5238: 5178: 5174: 5152: 5146: 5140: 5134: 5057: 5052: 5046: 5030: 5020: 5003: 4997: 4991: 4950: 4944: 4871: 4866: 4860: 4844: 4834: 4814: 4729: 4723: 4718: 4679: 4673: 4525: 4519: 4419: 4400: 4394: 4388: 4377: 4371: 4327: 4321: 4303: 4297: 4292: 4232: 4226: 4202: 4196: 4154: 4148: 4122: 4116: 4075: 4069: 4037: 4031: 3989: 3983: 3956: 3950: 3914: 3910: 3904: 3888: 3881: 3875: 3832: 3826: 3812: 3806: 3788: 3782: 3610: 3604: 3553: 3547: 3541: 3456: 3450: 3424: 3418: 3395: 3389: 3366: 3360: 3266: 3258: 3238: 3223: 3158: 3150: 3124: 3109: 3087: 3081: 3036: 3021: 3002: 2987: 2958: 2943: 2931: 2925: 2874: 2865: 2817: 2808: 2745: 2736: 2721: 2712: 2700: 2694: 2688: 2673: 2667: 2654: 2648: 2626: 2617: 2563: 2557: 2551: 2486: 2477: 2465: 2459: 2400: 2394: 2371: 2368: 2362: 2342: 2330: 2324: 2297: 2291: 2254: 2251: 2245: 2230: 2204: 2201: 2195: 2180: 2168: 2162: 2123: 2117: 2056: 2050: 2033: 2027: 2018: 2012: 1971: 1965: 1956: 1950: 1941: 1935: 1856: 1850: 1823: 1820: 1814: 1808: 1792: 1786: 1780: 1741: 1735: 1729: 1714: 1708: 1690: 1687: 1681: 1675: 1651: 1645: 1607: 1601: 1571: 1565: 1549: 1543: 1480: 1474: 1432: 1426: 1410: 1404: 1364: 1361: 1355: 1346: 1340: 1328: 1322: 1316: 1286: 1283: 1277: 1262: 1235: 1229: 1190: 1184: 1152: 1146: 1109: 1100: 1090: 1072: 1066: 1051: 985: 975: 921: 915: 871: 865: 825: 819: 789: 783: 760: 754: 719: 713: 681: 675: 636: 630: 624: 618: 606: 600: 591: 585: 577: 571: 549: 543: 456: 450: 415: 409: 385: 379: 340: 334: 301: 294: 259: 252: 243: 234: 158: 152: 125: 119: 1: 5760:and help improve the section. 5550: 3738: 2521:{\displaystyle \omega >0.} 2148:Negative frequency components 96: 3510:{\displaystyle \omega >0} 3336: 2907: 2444: 7: 5468: 4923:{\displaystyle \omega _{0}} 4782:{\displaystyle \omega _{0}} 4647:{\displaystyle \omega _{0}} 4592:{\displaystyle \omega _{0}} 4558:{\displaystyle \omega _{0}} 4498:{\displaystyle \omega _{0}} 4457:{\displaystyle \omega _{0}} 4091:The time derivative of the 2439: 10: 5859: 5620:10.1109/TASSP.1979.1163321 5497:Single-sideband modulation 18: 5656:. John Wiley & Sons. 5212:Wigner–Ville distribution 4265:Complex envelope/baseband 5512: 5250:{\displaystyle s_{m}(t)} 4956:{\displaystyle \phi (t)} 4565:might be equated to its 313:{\displaystyle S(f)^{*}} 19:Not to be confused with 5838:Time–frequency analysis 5791:Time-frequency analysis 5653:Time-Frequency Analysis 5099:{\displaystyle \theta } 4538:is a modulated signal, 4176:instantaneous frequency 3930:instantaneous amplitude 696:Heaviside step function 59:analytic representation 44:complex-valued function 5435: 5406: 5377: 5334: 5312: 5261:generalizing constant 5251: 5201: 5100: 5078: 4957: 4924: 4895: 4789:is chosen to minimize 4783: 4736: 4689: 4648: 4593: 4559: 4532: 4499: 4458: 4431: 4242: 4164: 4082: 4044: 4001: 3922: 3844: 3753: 3729: 3511: 3485: 3431: 3402: 3373: 3327: 3050: 2894: 2778: 2522: 2496: 2430: 2410: 2378: 2304: 2261: 2211: 2138: 1981: 1911: 1885: 1863: 1830: 1755: 1197: 1159: 1123: 796: 767: 742:non-negative frequency 726: 688: 650: 347: 314: 275: 215: 185: 165: 132: 106: 5436: 5407: 5378: 5335: 5313: 5252: 5202: 5101: 5079: 4958: 4925: 4896: 4784: 4737: 4690: 4649: 4594: 4560: 4533: 4500: 4459: 4432: 4243: 4165: 4083: 4045: 4002: 3923: 3845: 3751: 3730: 3512: 3486: 3432: 3403: 3379:for a complex-valued 3374: 3328: 3051: 2895: 2787:The last equality is 2779: 2523: 2497: 2431: 2411: 2409:{\displaystyle s(t).} 2379: 2305: 2262: 2212: 2139: 1982: 1912: 1886: 1864: 1831: 1756: 1198: 1160: 1124: 797: 768: 727: 689: 651: 348: 315: 276: 216: 186: 166: 133: 104: 5445:The monogenic signal 5416: 5387: 5344: 5322: 5293: 5284:negative frequencies 5225: 5110: 5090: 4967: 4938: 4934:instantaneous phase 4907: 4793: 4766: 4699: 4658: 4631: 4576: 4542: 4531:{\displaystyle s(t)} 4513: 4482: 4441: 4273: 4259:amplitude modulation 4190: 4110: 4099:, and is called the 4054: 4043:{\displaystyle s(t)} 4025: 3944: 3860: 3767: 3528: 3495: 3444: 3430:{\displaystyle s(t)} 3412: 3401:{\displaystyle s(t)} 3383: 3345: 3066: 2919: 2799: 2538: 2506: 2453: 2420: 2388: 2318: 2271: 2221: 2156: 1997: 1929: 1901: 1875: 1862:{\displaystyle s(t)} 1844: 1771: 1210: 1169: 1158:{\displaystyle s(t)} 1140: 1021:(Hermitian symmetry) 809: 795:{\displaystyle S(f)} 777: 766:{\displaystyle S(f)} 748: 704: 666: 360: 346:{\displaystyle S(f)} 328: 288: 228: 199: 175: 164:{\displaystyle S(f)} 146: 131:{\displaystyle s(t)} 113: 5796:Frederick W. King, 5465:-variable signals. 5133: 4990: 4813: 4010:instantaneous phase 2502:  where   2361: 2290: 214:{\displaystyle f=0} 195:symmetry about the 21:analytic expression 5798:Hilbert Transforms 5485:Negative frequency 5431: 5402: 5373: 5330: 5308: 5247: 5197: 5113: 5096: 5074: 4970: 4953: 4920: 4891: 4796: 4779: 4732: 4685: 4644: 4589: 4555: 4528: 4495: 4454: 4427: 4238: 4160: 4078: 4040: 3997: 3918: 3840: 3754: 3725: 3723: 3507: 3481: 3427: 3398: 3369: 3323: 3318: 3046: 2902:negative frequency 2890: 2774: 2772: 2518: 2492: 2426: 2406: 2374: 2345: 2300: 2274: 2257: 2207: 2134: 2130: 2088: 1977: 1907: 1881: 1859: 1826: 1751: 1749: 1694: 1662: 1575: 1559: 1512: 1490: 1436: 1420: 1193: 1155: 1119: 1117: 1026: 792: 763: 740:contains only the 722: 684: 646: 644: 581: 556: 515: 343: 310: 271: 211: 181: 161: 128: 107: 79:Hermitian symmetry 48:negative frequency 5833:Signal processing 5786: 5785: 5778: 5502:Quadrature filter 5428: 5399: 5364: 5305: 5219:complex amplitude 4753:inverted sideband 4612:(discrete-time), 4567:carrier frequency 4255:modulated signals 4221: 4146: 3758:polar coordinates 3544: 3306: 3302: 3248: 3195: 3191: 3140: 3134: 3131: 2972: 2831: 2691: 2601: 2554: 2078: 2041: 2039: 1910:{\displaystyle j} 1884:{\displaystyle *} 1838:Hilbert transform 1783: 1732: 1637: 1618: 1616: 1587: 1585: 1580: 1518: 1516: 1509: 1446: 1444: 1379: 1377: 1049: 1022: 1018: 1006: 1002: 961: 936: 932: 886: 882: 851: 532: 530: 503: 499: 471: 467: 430: 426: 322:complex conjugate 184:{\displaystyle f} 71:Fourier transform 52:Hilbert transform 36:signal processing 25:analytic function 5850: 5843:Fourier analysis 5781: 5774: 5770: 5767: 5761: 5756:Please read the 5752:may need cleanup 5741: 5740: 5733: 5722: 5721: 5701: 5695: 5694: 5674: 5668: 5667: 5647: 5641: 5638: 5632: 5631: 5603: 5597: 5594: 5588: 5583:Bracewell, Ron. 5581: 5572: 5561: 5544: 5541: 5535: 5532: 5526: 5523: 5460: 5451:monogenic signal 5440: 5438: 5437: 5432: 5430: 5429: 5421: 5411: 5409: 5408: 5403: 5401: 5400: 5392: 5382: 5380: 5379: 5374: 5366: 5365: 5357: 5351: 5339: 5337: 5336: 5331: 5329: 5317: 5315: 5314: 5309: 5307: 5306: 5298: 5256: 5254: 5253: 5248: 5237: 5236: 5206: 5204: 5203: 5198: 5186: 5185: 5164: 5163: 5132: 5124: 5105: 5103: 5102: 5097: 5083: 5081: 5080: 5075: 5066: 5065: 5060: 5045: 5044: 5043: 5033: 5028: 5027: 5018: 5017: 4989: 4981: 4962: 4960: 4959: 4954: 4929: 4927: 4926: 4921: 4919: 4918: 4900: 4898: 4897: 4892: 4880: 4879: 4874: 4859: 4858: 4857: 4847: 4842: 4841: 4832: 4831: 4812: 4804: 4788: 4786: 4785: 4780: 4778: 4777: 4741: 4739: 4738: 4733: 4722: 4721: 4716: 4715: 4714: 4713: 4694: 4692: 4691: 4686: 4672: 4671: 4670: 4653: 4651: 4650: 4645: 4643: 4642: 4598: 4596: 4595: 4590: 4588: 4587: 4572:In other cases, 4564: 4562: 4561: 4556: 4554: 4553: 4537: 4535: 4534: 4529: 4507:passband signals 4504: 4502: 4501: 4496: 4494: 4493: 4469:complex envelope 4463: 4461: 4460: 4455: 4453: 4452: 4436: 4434: 4433: 4428: 4423: 4422: 4415: 4414: 4370: 4369: 4368: 4355: 4354: 4350: 4349: 4320: 4319: 4318: 4296: 4295: 4290: 4289: 4288: 4287: 4247: 4245: 4244: 4239: 4222: 4220: 4209: 4183:) is therefore: 4169: 4167: 4166: 4161: 4147: 4145: 4137: 4129: 4087: 4085: 4084: 4079: 4068: 4067: 4066: 4049: 4047: 4046: 4041: 4006: 4004: 4003: 3998: 3996: 3992: 3982: 3981: 3980: 3927: 3925: 3924: 3919: 3917: 3903: 3902: 3901: 3891: 3874: 3873: 3872: 3849: 3847: 3846: 3841: 3836: 3835: 3805: 3804: 3803: 3781: 3780: 3779: 3734: 3732: 3731: 3726: 3724: 3714: 3713: 3692: 3691: 3670: 3669: 3651: 3650: 3638: 3637: 3603: 3602: 3601: 3584: 3583: 3546: 3545: 3537: 3516: 3514: 3513: 3508: 3490: 3488: 3487: 3482: 3480: 3479: 3436: 3434: 3433: 3428: 3407: 3405: 3404: 3399: 3378: 3376: 3375: 3370: 3359: 3358: 3357: 3332: 3330: 3329: 3324: 3322: 3321: 3304: 3303: 3300: 3293: 3292: 3274: 3273: 3269: 3261: 3246: 3242: 3241: 3193: 3192: 3189: 3182: 3181: 3166: 3165: 3161: 3153: 3138: 3132: 3129: 3128: 3127: 3080: 3079: 3078: 3055: 3053: 3052: 3047: 3045: 3041: 3040: 3039: 3006: 3005: 2973: 2965: 2899: 2897: 2896: 2891: 2886: 2882: 2881: 2880: 2853: 2852: 2832: 2824: 2783: 2781: 2780: 2775: 2773: 2766: 2765: 2693: 2692: 2684: 2647: 2646: 2645: 2607: 2603: 2602: 2594: 2556: 2555: 2547: 2527: 2525: 2524: 2519: 2501: 2499: 2498: 2493: 2435: 2433: 2432: 2427: 2415: 2413: 2412: 2407: 2383: 2381: 2380: 2375: 2360: 2355: 2354: 2309: 2307: 2306: 2301: 2289: 2284: 2283: 2266: 2264: 2263: 2258: 2244: 2243: 2242: 2216: 2214: 2213: 2208: 2194: 2193: 2192: 2143: 2141: 2140: 2135: 2129: 2107: 2106: 2098: 2097: 2089: 2084: 2080: 2079: 2077: 2066: 2011: 2010: 2009: 1986: 1984: 1983: 1978: 1916: 1914: 1913: 1908: 1890: 1888: 1887: 1882: 1868: 1866: 1865: 1860: 1835: 1833: 1832: 1827: 1804: 1803: 1785: 1784: 1776: 1760: 1758: 1757: 1752: 1750: 1734: 1733: 1725: 1698: 1693: 1671: 1670: 1663: 1658: 1654: 1638: 1636: 1625: 1591: 1586: 1583: 1581: 1576: 1574: 1560: 1555: 1536: 1535: 1527: 1526: 1511: 1510: 1508: 1497: 1491: 1486: 1464: 1463: 1455: 1454: 1442: 1440: 1435: 1421: 1416: 1397: 1396: 1388: 1387: 1370: 1315: 1314: 1306: 1305: 1292: 1276: 1275: 1274: 1261: 1260: 1252: 1251: 1228: 1227: 1226: 1202: 1200: 1199: 1194: 1183: 1182: 1181: 1164: 1162: 1161: 1156: 1128: 1126: 1125: 1120: 1118: 1108: 1107: 1089: 1088: 1087: 1065: 1064: 1063: 1050: 1042: 1034: 1030: 1029: 1023: 1020: 1016: 1004: 1003: 1000: 993: 992: 974: 973: 972: 962: 954: 934: 933: 930: 914: 913: 912: 884: 883: 880: 864: 863: 862: 852: 844: 801: 799: 798: 793: 772: 770: 769: 764: 731: 729: 728: 723: 693: 691: 690: 685: 655: 653: 652: 647: 645: 580: 557: 552: 523: 519: 518: 501: 500: 497: 469: 468: 465: 428: 427: 424: 378: 377: 376: 353:. The function: 352: 350: 349: 344: 319: 317: 316: 311: 309: 308: 280: 278: 277: 272: 267: 266: 220: 218: 217: 212: 190: 188: 187: 182: 170: 168: 167: 162: 137: 135: 134: 129: 5858: 5857: 5853: 5852: 5851: 5849: 5848: 5847: 5823: 5822: 5814: 5782: 5771: 5765: 5762: 5755: 5748:Further reading 5742: 5738: 5731: 5729:Further reading 5726: 5725: 5718: 5702: 5698: 5691: 5675: 5671: 5664: 5648: 5644: 5639: 5635: 5604: 5600: 5595: 5591: 5582: 5575: 5562: 5558: 5553: 5548: 5547: 5542: 5538: 5533: 5529: 5524: 5520: 5515: 5493: 5471: 5454: 5447: 5420: 5419: 5417: 5414: 5413: 5391: 5390: 5388: 5385: 5384: 5356: 5355: 5347: 5345: 5342: 5341: 5340:as negative if 5325: 5323: 5320: 5319: 5297: 5296: 5294: 5291: 5290: 5280: 5271: 5232: 5228: 5226: 5223: 5222: 5181: 5177: 5159: 5155: 5125: 5117: 5111: 5108: 5107: 5091: 5088: 5087: 5061: 5056: 5055: 5039: 5038: 5034: 5029: 5023: 5019: 5013: 5009: 4982: 4974: 4968: 4965: 4964: 4939: 4936: 4935: 4914: 4910: 4908: 4905: 4904: 4903:Alternatively, 4875: 4870: 4869: 4853: 4852: 4848: 4843: 4837: 4833: 4827: 4823: 4805: 4800: 4794: 4791: 4790: 4773: 4769: 4767: 4764: 4763: 4745:single-sideband 4717: 4709: 4708: 4704: 4703: 4702: 4700: 4697: 4696: 4666: 4665: 4661: 4659: 4656: 4655: 4638: 4634: 4632: 4629: 4628: 4601:low-pass filter 4583: 4579: 4577: 4574: 4573: 4549: 4545: 4543: 4540: 4539: 4514: 4511: 4510: 4489: 4485: 4483: 4480: 4479: 4448: 4444: 4442: 4439: 4438: 4410: 4406: 4384: 4380: 4364: 4363: 4359: 4345: 4341: 4334: 4330: 4314: 4313: 4309: 4291: 4283: 4282: 4278: 4277: 4276: 4274: 4271: 4270: 4267: 4213: 4208: 4191: 4188: 4187: 4138: 4130: 4128: 4111: 4108: 4107: 4062: 4061: 4057: 4055: 4052: 4051: 4026: 4023: 4022: 3976: 3975: 3971: 3970: 3966: 3945: 3942: 3941: 3913: 3897: 3896: 3892: 3887: 3868: 3867: 3863: 3861: 3858: 3857: 3819: 3815: 3799: 3798: 3794: 3775: 3774: 3770: 3768: 3765: 3764: 3746: 3741: 3722: 3721: 3700: 3696: 3678: 3674: 3656: 3652: 3646: 3642: 3624: 3620: 3613: 3597: 3596: 3592: 3589: 3588: 3570: 3566: 3556: 3536: 3535: 3531: 3529: 3526: 3525: 3496: 3493: 3492: 3466: 3462: 3445: 3442: 3441: 3413: 3410: 3409: 3384: 3381: 3380: 3353: 3352: 3348: 3346: 3343: 3342: 3339: 3317: 3316: 3299: 3297: 3282: 3278: 3265: 3257: 3253: 3249: 3216: 3212: 3209: 3208: 3188: 3186: 3174: 3170: 3157: 3149: 3145: 3141: 3105: 3101: 3094: 3093: 3074: 3073: 3069: 3067: 3064: 3063: 3014: 3010: 2983: 2979: 2978: 2974: 2964: 2920: 2917: 2916: 2910: 2861: 2857: 2842: 2838: 2837: 2833: 2823: 2800: 2797: 2796: 2789:Euler's formula 2771: 2770: 2755: 2751: 2683: 2682: 2657: 2641: 2640: 2636: 2633: 2632: 2593: 2583: 2579: 2566: 2546: 2545: 2541: 2539: 2536: 2535: 2507: 2504: 2503: 2454: 2451: 2450: 2447: 2442: 2421: 2418: 2417: 2389: 2386: 2385: 2356: 2350: 2349: 2319: 2316: 2315: 2285: 2279: 2278: 2272: 2269: 2268: 2238: 2237: 2233: 2222: 2219: 2218: 2188: 2187: 2183: 2157: 2154: 2153: 2150: 2099: 2093: 2092: 2091: 2090: 2070: 2065: 2046: 2042: 2040: 2005: 2004: 2000: 1998: 1995: 1994: 1930: 1927: 1926: 1902: 1899: 1898: 1876: 1873: 1872: 1845: 1842: 1841: 1799: 1798: 1775: 1774: 1772: 1769: 1768: 1748: 1747: 1724: 1723: 1696: 1695: 1666: 1665: 1664: 1629: 1624: 1623: 1619: 1617: 1589: 1588: 1582: 1561: 1528: 1522: 1521: 1520: 1519: 1517: 1501: 1496: 1492: 1456: 1450: 1449: 1448: 1447: 1445: 1443: 1441: 1422: 1389: 1383: 1382: 1381: 1380: 1378: 1368: 1367: 1307: 1301: 1300: 1299: 1290: 1289: 1270: 1269: 1265: 1253: 1247: 1246: 1245: 1238: 1222: 1221: 1217: 1213: 1211: 1208: 1207: 1177: 1176: 1172: 1170: 1167: 1166: 1141: 1138: 1137: 1134:analytic signal 1116: 1115: 1103: 1099: 1083: 1082: 1078: 1059: 1058: 1054: 1041: 1032: 1031: 1025: 1024: 1019: 999: 997: 988: 984: 968: 967: 963: 953: 950: 949: 929: 927: 908: 907: 903: 900: 899: 879: 877: 858: 857: 853: 843: 836: 835: 828: 812: 810: 807: 806: 778: 775: 774: 749: 746: 745: 705: 702: 701: 667: 664: 663: 643: 642: 558: 533: 531: 521: 520: 514: 513: 496: 494: 485: 484: 464: 462: 444: 443: 423: 421: 396: 395: 388: 372: 371: 367: 363: 361: 358: 357: 329: 326: 325: 304: 300: 289: 286: 285: 262: 258: 229: 226: 225: 200: 197: 196: 176: 173: 172: 147: 144: 143: 114: 111: 110: 99: 67:analytic signal 65:function is an 40:analytic signal 28: 17: 12: 11: 5: 5856: 5846: 5845: 5840: 5835: 5821: 5820: 5813: 5812:External links 5810: 5809: 5808: 5801: 5794: 5784: 5783: 5745: 5743: 5736: 5730: 5727: 5724: 5723: 5716: 5696: 5689: 5669: 5662: 5642: 5633: 5614:(6): 670–684. 5598: 5589: 5573: 5555: 5554: 5552: 5549: 5546: 5545: 5536: 5527: 5517: 5516: 5514: 5511: 5510: 5509: 5504: 5499: 5492: 5489: 5488: 5487: 5482: 5477: 5470: 5467: 5446: 5443: 5427: 5424: 5398: 5395: 5372: 5369: 5363: 5360: 5354: 5350: 5328: 5304: 5301: 5279: 5276: 5270: 5267: 5246: 5243: 5240: 5235: 5231: 5208: 5207: 5196: 5193: 5190: 5184: 5180: 5176: 5173: 5170: 5167: 5162: 5158: 5154: 5151: 5148: 5145: 5142: 5139: 5136: 5131: 5128: 5123: 5120: 5116: 5095: 5084: 5073: 5070: 5064: 5059: 5054: 5051: 5048: 5042: 5037: 5032: 5026: 5022: 5016: 5012: 5008: 5005: 5002: 4999: 4996: 4993: 4988: 4985: 4980: 4977: 4973: 4952: 4949: 4946: 4943: 4917: 4913: 4901: 4890: 4887: 4884: 4878: 4873: 4868: 4865: 4862: 4856: 4851: 4846: 4840: 4836: 4830: 4826: 4822: 4819: 4816: 4811: 4808: 4803: 4799: 4776: 4772: 4749:lower sideband 4747:signal called 4731: 4728: 4725: 4720: 4712: 4707: 4684: 4681: 4678: 4675: 4669: 4664: 4641: 4637: 4586: 4582: 4552: 4548: 4527: 4524: 4521: 4518: 4492: 4488: 4451: 4447: 4426: 4421: 4418: 4413: 4409: 4405: 4402: 4399: 4396: 4393: 4390: 4387: 4383: 4379: 4376: 4373: 4367: 4362: 4358: 4353: 4348: 4344: 4340: 4337: 4333: 4329: 4326: 4323: 4317: 4312: 4308: 4305: 4302: 4299: 4294: 4286: 4281: 4266: 4263: 4250: 4249: 4237: 4234: 4231: 4228: 4225: 4219: 4216: 4212: 4207: 4204: 4201: 4198: 4195: 4171: 4170: 4159: 4156: 4153: 4150: 4144: 4141: 4136: 4133: 4127: 4124: 4121: 4118: 4115: 4097:radians/second 4077: 4074: 4071: 4065: 4060: 4039: 4036: 4033: 4030: 4019: 4018: 4007:is called the 3995: 3991: 3988: 3985: 3979: 3974: 3969: 3964: 3961: 3958: 3955: 3952: 3949: 3939: 3928:is called the 3916: 3912: 3909: 3906: 3900: 3895: 3890: 3886: 3883: 3880: 3877: 3871: 3866: 3851: 3850: 3839: 3834: 3831: 3828: 3825: 3822: 3818: 3814: 3811: 3808: 3802: 3797: 3793: 3790: 3787: 3784: 3778: 3773: 3745: 3742: 3740: 3737: 3736: 3735: 3720: 3717: 3712: 3709: 3706: 3703: 3699: 3695: 3690: 3687: 3684: 3681: 3677: 3673: 3668: 3665: 3662: 3659: 3655: 3649: 3645: 3641: 3636: 3633: 3630: 3627: 3623: 3619: 3616: 3614: 3612: 3609: 3606: 3600: 3595: 3591: 3590: 3587: 3582: 3579: 3576: 3573: 3569: 3565: 3562: 3559: 3557: 3555: 3552: 3549: 3543: 3540: 3534: 3533: 3519: 3518: 3506: 3503: 3500: 3478: 3475: 3472: 3469: 3465: 3461: 3458: 3455: 3452: 3449: 3426: 3423: 3420: 3417: 3397: 3394: 3391: 3388: 3368: 3365: 3362: 3356: 3351: 3338: 3335: 3334: 3333: 3320: 3315: 3312: 3309: 3298: 3296: 3291: 3288: 3285: 3281: 3277: 3272: 3268: 3264: 3260: 3256: 3252: 3245: 3240: 3237: 3234: 3231: 3228: 3225: 3222: 3219: 3215: 3211: 3210: 3207: 3204: 3201: 3198: 3187: 3185: 3180: 3177: 3173: 3169: 3164: 3160: 3156: 3152: 3148: 3144: 3137: 3126: 3123: 3120: 3117: 3114: 3111: 3108: 3104: 3100: 3099: 3097: 3092: 3089: 3086: 3083: 3077: 3072: 3057: 3056: 3044: 3038: 3035: 3032: 3029: 3026: 3023: 3020: 3017: 3013: 3009: 3004: 3001: 2998: 2995: 2992: 2989: 2986: 2982: 2977: 2971: 2968: 2963: 2960: 2957: 2954: 2951: 2948: 2945: 2942: 2939: 2936: 2933: 2930: 2927: 2924: 2909: 2906: 2889: 2885: 2879: 2876: 2873: 2870: 2867: 2864: 2860: 2856: 2851: 2848: 2845: 2841: 2836: 2830: 2827: 2822: 2819: 2816: 2813: 2810: 2807: 2804: 2785: 2784: 2769: 2764: 2761: 2758: 2754: 2750: 2747: 2744: 2741: 2738: 2735: 2732: 2729: 2726: 2723: 2720: 2717: 2714: 2711: 2708: 2705: 2702: 2699: 2696: 2690: 2687: 2681: 2678: 2675: 2672: 2669: 2666: 2663: 2660: 2658: 2656: 2653: 2650: 2644: 2639: 2635: 2634: 2631: 2628: 2625: 2622: 2619: 2616: 2613: 2610: 2606: 2600: 2597: 2592: 2589: 2586: 2582: 2578: 2575: 2572: 2569: 2567: 2565: 2562: 2559: 2553: 2550: 2544: 2543: 2529: 2528: 2517: 2514: 2511: 2491: 2488: 2485: 2482: 2479: 2476: 2473: 2470: 2467: 2464: 2461: 2458: 2446: 2443: 2441: 2438: 2425: 2405: 2402: 2399: 2396: 2393: 2373: 2370: 2367: 2364: 2359: 2353: 2348: 2344: 2341: 2338: 2335: 2332: 2329: 2326: 2323: 2299: 2296: 2293: 2288: 2282: 2277: 2256: 2253: 2250: 2247: 2241: 2236: 2232: 2229: 2226: 2206: 2203: 2200: 2197: 2191: 2186: 2182: 2179: 2176: 2173: 2170: 2167: 2164: 2161: 2149: 2146: 2145: 2144: 2133: 2128: 2125: 2122: 2119: 2116: 2113: 2110: 2105: 2102: 2096: 2087: 2083: 2076: 2073: 2069: 2064: 2061: 2058: 2055: 2052: 2049: 2045: 2038: 2035: 2032: 2029: 2026: 2023: 2020: 2017: 2014: 2008: 2003: 1976: 1973: 1970: 1967: 1964: 1961: 1958: 1955: 1952: 1949: 1946: 1943: 1940: 1937: 1934: 1923: 1922: 1919:imaginary unit 1906: 1896: 1891:is the binary 1880: 1870: 1858: 1855: 1852: 1849: 1825: 1822: 1819: 1816: 1813: 1810: 1807: 1802: 1797: 1794: 1791: 1788: 1782: 1779: 1762: 1761: 1746: 1743: 1740: 1737: 1731: 1728: 1722: 1719: 1716: 1713: 1710: 1707: 1704: 1701: 1699: 1697: 1692: 1689: 1686: 1683: 1680: 1677: 1674: 1669: 1661: 1657: 1653: 1650: 1647: 1644: 1641: 1635: 1632: 1628: 1622: 1615: 1612: 1609: 1606: 1603: 1600: 1597: 1594: 1592: 1590: 1579: 1573: 1570: 1567: 1564: 1558: 1554: 1551: 1548: 1545: 1542: 1539: 1534: 1531: 1525: 1515: 1507: 1504: 1500: 1495: 1489: 1485: 1482: 1479: 1476: 1473: 1470: 1467: 1462: 1459: 1453: 1439: 1434: 1431: 1428: 1425: 1419: 1415: 1412: 1409: 1406: 1403: 1400: 1395: 1392: 1386: 1376: 1373: 1371: 1369: 1366: 1363: 1360: 1357: 1354: 1351: 1348: 1345: 1342: 1339: 1336: 1333: 1330: 1327: 1324: 1321: 1318: 1313: 1310: 1304: 1298: 1295: 1293: 1291: 1288: 1285: 1282: 1279: 1273: 1268: 1264: 1259: 1256: 1250: 1244: 1241: 1239: 1237: 1234: 1231: 1225: 1220: 1216: 1215: 1192: 1189: 1186: 1180: 1175: 1154: 1151: 1148: 1145: 1130: 1129: 1114: 1111: 1106: 1102: 1098: 1095: 1092: 1086: 1081: 1077: 1074: 1071: 1068: 1062: 1057: 1053: 1048: 1045: 1040: 1037: 1035: 1033: 1028: 1015: 1012: 1009: 998: 996: 991: 987: 983: 980: 977: 971: 966: 960: 957: 952: 951: 948: 945: 942: 939: 928: 926: 923: 920: 917: 911: 906: 902: 901: 898: 895: 892: 889: 878: 876: 873: 870: 867: 861: 856: 850: 847: 842: 841: 839: 834: 831: 829: 827: 824: 821: 818: 815: 814: 791: 788: 785: 782: 762: 759: 756: 753: 744:components of 738: 737: 721: 718: 715: 712: 709: 699: 683: 680: 677: 674: 671: 657: 656: 641: 638: 635: 632: 629: 626: 623: 620: 617: 614: 611: 608: 605: 602: 599: 596: 593: 590: 587: 584: 579: 576: 573: 570: 567: 564: 561: 555: 551: 548: 545: 542: 539: 536: 529: 526: 524: 522: 517: 512: 509: 506: 495: 493: 490: 487: 486: 483: 480: 477: 474: 463: 461: 458: 455: 452: 449: 446: 445: 442: 439: 436: 433: 422: 420: 417: 414: 411: 408: 405: 402: 401: 399: 394: 391: 389: 387: 384: 381: 375: 370: 366: 365: 342: 339: 336: 333: 307: 303: 299: 296: 293: 282: 281: 270: 265: 261: 257: 254: 251: 248: 245: 242: 239: 236: 233: 210: 207: 204: 180: 160: 157: 154: 151: 127: 124: 121: 118: 98: 95: 15: 9: 6: 4: 3: 2: 5855: 5844: 5841: 5839: 5836: 5834: 5831: 5830: 5828: 5819: 5816: 5815: 5806: 5803:B. Boashash, 5802: 5799: 5795: 5792: 5788: 5787: 5780: 5777: 5769: 5759: 5758:editing guide 5753: 5749: 5744: 5735: 5734: 5719: 5717:9781586031015 5713: 5710:. IOS Press. 5709: 5708: 5700: 5692: 5690:9780824742508 5686: 5683:. CRC Press. 5682: 5681: 5673: 5665: 5663:9781118623831 5659: 5655: 5654: 5646: 5637: 5629: 5625: 5621: 5617: 5613: 5609: 5602: 5593: 5586: 5580: 5578: 5570: 5566: 5560: 5556: 5540: 5531: 5522: 5518: 5508: 5507:Causal filter 5505: 5503: 5500: 5498: 5495: 5494: 5486: 5483: 5481: 5478: 5476: 5473: 5472: 5466: 5464: 5458: 5452: 5442: 5370: 5367: 5352: 5289: 5285: 5275: 5266: 5264: 5260: 5241: 5233: 5229: 5220: 5215: 5213: 5194: 5191: 5188: 5182: 5171: 5168: 5165: 5160: 5156: 5149: 5143: 5137: 5126: 5118: 5114: 5093: 5085: 5071: 5068: 5062: 5049: 5035: 5024: 5014: 5010: 5006: 5000: 4994: 4983: 4975: 4971: 4947: 4941: 4933: 4915: 4911: 4902: 4888: 4885: 4882: 4876: 4863: 4849: 4838: 4828: 4824: 4820: 4817: 4806: 4801: 4797: 4774: 4770: 4761: 4760: 4759: 4756: 4754: 4750: 4746: 4726: 4705: 4682: 4676: 4662: 4639: 4635: 4625: 4623: 4619: 4615: 4614:interpolation 4611: 4607: 4602: 4584: 4580: 4570: 4568: 4550: 4546: 4522: 4516: 4508: 4490: 4486: 4477: 4476: 4470: 4465: 4449: 4445: 4424: 4416: 4411: 4407: 4403: 4397: 4391: 4385: 4381: 4374: 4360: 4356: 4351: 4346: 4342: 4338: 4335: 4331: 4324: 4310: 4306: 4300: 4279: 4262: 4260: 4256: 4235: 4229: 4223: 4217: 4214: 4210: 4205: 4199: 4193: 4186: 4185: 4184: 4182: 4178: 4177: 4157: 4151: 4142: 4139: 4134: 4131: 4125: 4119: 4113: 4106: 4105: 4104: 4102: 4098: 4094: 4089: 4072: 4058: 4034: 4028: 4016: 4012: 4011: 3993: 3986: 3972: 3967: 3962: 3959: 3953: 3947: 3940: 3937: 3936: 3931: 3907: 3893: 3884: 3878: 3864: 3856: 3855: 3854: 3837: 3829: 3823: 3820: 3816: 3809: 3795: 3791: 3785: 3771: 3763: 3762: 3761: 3759: 3750: 3718: 3715: 3710: 3707: 3704: 3701: 3697: 3693: 3688: 3685: 3682: 3679: 3675: 3671: 3666: 3663: 3660: 3657: 3653: 3647: 3643: 3639: 3634: 3631: 3628: 3625: 3621: 3617: 3615: 3607: 3593: 3585: 3580: 3577: 3574: 3571: 3567: 3563: 3560: 3558: 3550: 3538: 3524: 3523: 3522: 3504: 3501: 3498: 3476: 3473: 3470: 3467: 3463: 3459: 3453: 3447: 3440: 3439: 3438: 3421: 3415: 3392: 3386: 3363: 3349: 3313: 3310: 3307: 3294: 3289: 3286: 3283: 3279: 3275: 3270: 3262: 3254: 3250: 3243: 3235: 3232: 3229: 3226: 3220: 3217: 3213: 3205: 3202: 3199: 3196: 3183: 3178: 3175: 3171: 3167: 3162: 3154: 3146: 3142: 3135: 3121: 3118: 3115: 3112: 3106: 3102: 3095: 3090: 3084: 3070: 3062: 3061: 3060: 3042: 3033: 3030: 3027: 3024: 3018: 3015: 3011: 3007: 2999: 2996: 2993: 2990: 2984: 2980: 2975: 2969: 2966: 2961: 2955: 2952: 2949: 2946: 2940: 2937: 2934: 2928: 2922: 2915: 2914: 2913: 2905: 2903: 2887: 2883: 2877: 2871: 2868: 2862: 2858: 2854: 2849: 2846: 2843: 2839: 2834: 2828: 2825: 2820: 2814: 2811: 2805: 2802: 2794: 2791:, of which a 2790: 2767: 2762: 2759: 2756: 2752: 2748: 2742: 2739: 2733: 2730: 2727: 2724: 2718: 2715: 2709: 2706: 2703: 2697: 2685: 2679: 2676: 2670: 2664: 2661: 2659: 2651: 2637: 2629: 2623: 2620: 2614: 2611: 2608: 2604: 2598: 2595: 2590: 2587: 2584: 2580: 2576: 2573: 2570: 2568: 2560: 2548: 2534: 2533: 2532: 2515: 2512: 2509: 2489: 2483: 2480: 2474: 2471: 2468: 2462: 2456: 2449: 2448: 2437: 2423: 2403: 2397: 2391: 2365: 2357: 2346: 2339: 2336: 2333: 2327: 2321: 2313: 2294: 2286: 2275: 2248: 2234: 2227: 2224: 2198: 2184: 2177: 2174: 2171: 2165: 2159: 2131: 2120: 2114: 2111: 2103: 2100: 2085: 2081: 2074: 2071: 2067: 2062: 2059: 2053: 2047: 2043: 2036: 2030: 2024: 2021: 2015: 2001: 1993: 1992: 1991: 1990: 1974: 1968: 1962: 1959: 1953: 1947: 1944: 1938: 1932: 1920: 1904: 1897: 1894: 1878: 1871: 1853: 1847: 1839: 1817: 1811: 1805: 1795: 1789: 1777: 1767: 1766: 1765: 1744: 1738: 1726: 1720: 1717: 1711: 1705: 1702: 1700: 1684: 1678: 1672: 1659: 1655: 1648: 1642: 1639: 1633: 1630: 1626: 1620: 1613: 1610: 1604: 1598: 1595: 1593: 1577: 1568: 1562: 1556: 1546: 1540: 1532: 1529: 1513: 1505: 1502: 1498: 1493: 1487: 1477: 1471: 1468: 1460: 1457: 1437: 1429: 1423: 1417: 1407: 1401: 1393: 1390: 1374: 1372: 1358: 1352: 1349: 1343: 1337: 1334: 1331: 1325: 1319: 1311: 1308: 1296: 1294: 1280: 1266: 1257: 1254: 1242: 1240: 1232: 1218: 1206: 1205: 1204: 1187: 1173: 1149: 1143: 1135: 1112: 1104: 1096: 1093: 1079: 1075: 1069: 1055: 1046: 1043: 1038: 1036: 1013: 1010: 1007: 994: 989: 981: 978: 964: 958: 955: 946: 943: 940: 937: 924: 918: 904: 896: 893: 890: 887: 874: 868: 854: 848: 845: 837: 832: 830: 822: 816: 805: 804: 803: 786: 780: 757: 751: 743: 735: 734:sign function 716: 710: 707: 700: 697: 678: 672: 662: 661: 660: 639: 633: 627: 621: 615: 612: 609: 603: 597: 594: 588: 582: 574: 568: 565: 562: 559: 553: 546: 540: 534: 527: 525: 510: 507: 504: 491: 488: 481: 478: 475: 472: 459: 453: 447: 440: 437: 434: 431: 418: 412: 406: 403: 397: 392: 390: 382: 368: 356: 355: 354: 337: 331: 323: 305: 297: 291: 268: 263: 255: 249: 246: 240: 237: 231: 224: 223: 222: 208: 205: 202: 194: 178: 155: 149: 141: 122: 116: 103: 94: 92: 88: 83: 80: 76: 72: 68: 64: 60: 55: 53: 49: 45: 41: 37: 33: 26: 22: 5804: 5797: 5790: 5789:Leon Cohen, 5772: 5766:October 2014 5763: 5751: 5706: 5699: 5679: 5672: 5652: 5645: 5636: 5611: 5607: 5601: 5592: 5584: 5559: 5539: 5530: 5521: 5491:Applications 5462: 5456: 5448: 5283: 5281: 5272: 5216: 5209: 4931: 4757: 4752: 4748: 4626: 4605: 4571: 4472: 4468: 4466: 4268: 4251: 4174: 4172: 4100: 4096: 4090: 4020: 4014: 4008: 3933: 3929: 3852: 3755: 3520: 3340: 3058: 2911: 2786: 2530: 2311: 2151: 1988: 1925:Noting that 1924: 1763: 1133: 1131: 741: 739: 658: 283: 139: 108: 86: 84: 66: 58: 56: 46:that has no 39: 29: 5288:unit vector 4015:phase angle 1893:convolution 1584:convolution 140:real-valued 63:real-valued 32:mathematics 5827:Categories 5750:" section 5551:References 4762:Sometimes 4618:upsampling 3739:Properties 2310:comprises 97:Definition 5628:0096-3518 5426:^ 5397:^ 5362:^ 5353:⋅ 5349:ξ 5327:ξ 5303:^ 5263:amplitude 5172:θ 5157:ω 5150:− 5138:ϕ 5130:∞ 5122:∞ 5119:− 5115:∫ 5094:θ 5011:ω 5007:− 4995:ω 4987:∞ 4979:∞ 4976:− 4972:∫ 4942:ϕ 4932:unwrapped 4912:ω 4886:ω 4864:ω 4825:ω 4821:− 4818:ω 4810:∞ 4798:∫ 4771:ω 4719:↓ 4636:ω 4581:ω 4547:ω 4487:ω 4446:ω 4408:ω 4404:− 4392:ϕ 4343:ω 4336:− 4307:≜ 4293:↓ 4224:ω 4218:π 4206:≜ 4135:ϕ 4126:≜ 4114:ω 4093:unwrapped 3960:≜ 3948:ϕ 3885:≜ 3824:ϕ 3708:ω 3702:− 3694:− 3686:ω 3680:− 3664:ω 3658:− 3632:ω 3626:− 3578:ω 3572:− 3542:^ 3499:ω 3474:ω 3468:− 3337:Example 3 3308:ω 3290:θ 3284:− 3276:⋅ 3263:ω 3236:θ 3227:ω 3218:− 3197:ω 3179:θ 3168:⋅ 3155:ω 3122:θ 3113:ω 3034:θ 3025:ω 3016:− 3000:θ 2991:ω 2956:θ 2947:ω 2941:⁡ 2908:Example 2 2872:ω 2869:− 2847:ω 2812:ω 2806:⁡ 2793:corollary 2760:ω 2740:ω 2734:⁡ 2716:ω 2710:⁡ 2689:^ 2621:ω 2615:⁡ 2596:π 2591:− 2585:ω 2577:⁡ 2552:^ 2510:ω 2481:ω 2475:⁡ 2445:Example 1 2358:∗ 2340:⁡ 2287:∗ 2228:⁡ 2178:⁡ 2101:− 2086:⏟ 2072:π 2048:δ 2037:∗ 1963:δ 1960:∗ 1895:operator; 1879:∗ 1806:⁡ 1796:≜ 1781:^ 1730:^ 1673:⁡ 1660:⏟ 1640:∗ 1631:π 1578:⏞ 1557:⏟ 1530:− 1514:∗ 1503:π 1488:⏟ 1472:⁡ 1458:− 1418:⏟ 1391:− 1350:⋅ 1338:⁡ 1309:− 1255:− 1243:≜ 1105:∗ 1094:− 990:∗ 979:− 711:⁡ 673:⁡ 616:⁡ 569:⁡ 554:⏟ 541:⁡ 393:≜ 306:∗ 264:∗ 238:− 193:Hermitian 5480:I/Q data 5469:See also 5259:envelope 4622:aliasing 4606:analytic 4475:baseband 4473:complex 3935:envelope 3491:, where 2440:Examples 87:analytic 75:spectrum 4610:sampled 3932:or the 1917:is the 1836:is the 732:is the 694:is the 320:is the 171:(where 5746:This " 5714:  5687:  5660:  5626:  4437:where 4248:  3521:Then: 3305:  3247:  3194:  3139:  3133:  3130:  3059:Then: 2531:Then: 2152:Since 1764:where 1017:  1005:  935:  885:  659:where 502:  470:  429:  284:where 221:axis: 91:phasor 5567:, or 5513:Notes 4695:then 4509:. If 4181:hertz 138:is a 61:of a 42:is a 38:, an 5712:ISBN 5685:ISBN 5658:ISBN 5624:ISSN 5459:+ 1) 5368:< 4471:and 4179:(in 4173:The 3502:> 3311:< 3200:> 2513:> 2416:The 2312:only 1132:The 1011:< 891:> 508:< 435:> 73:(or 57:The 34:and 5616:doi 5106:): 4751:or 4627:If 4013:or 3963:arg 2938:cos 2803:cos 2795:is 2731:sin 2707:cos 2612:sin 2574:cos 2472:cos 1840:of 1469:sgn 1335:sgn 1136:of 1001:for 931:for 881:for 708:sgn 613:sgn 566:sgn 498:for 466:for 425:for 324:of 109:If 30:In 23:or 5829:: 5622:. 5612:27 5610:. 5576:^ 5265:. 4963:: 4755:. 4624:. 4569:. 4103:: 4088:. 3760:: 3719:0. 3437:. 3314:0. 3301:if 3190:if 2516:0. 2424:Re 2337:Re 2225:Im 2175:Re 1203:: 802:: 54:. 5779:) 5773:( 5768:) 5764:( 5754:. 5720:. 5693:. 5666:. 5630:. 5618:: 5463:n 5457:n 5455:( 5423:u 5394:u 5371:0 5359:u 5300:u 5245:) 5242:t 5239:( 5234:m 5230:s 5195:. 5192:t 5189:d 5183:2 5179:] 5175:) 5169:+ 5166:t 5161:0 5153:( 5147:) 5144:t 5141:( 5135:[ 5127:+ 5072:t 5069:d 5063:2 5058:| 5053:) 5050:t 5047:( 5041:a 5036:s 5031:| 5025:2 5021:] 5015:0 5004:) 5001:t 4998:( 4992:[ 4984:+ 4951:) 4948:t 4945:( 4916:0 4889:. 4883:d 4877:2 4872:| 4867:) 4861:( 4855:a 4850:S 4845:| 4839:2 4835:) 4829:0 4815:( 4807:+ 4802:0 4775:0 4730:) 4727:t 4724:( 4711:a 4706:s 4683:, 4680:) 4677:t 4674:( 4668:a 4663:s 4640:0 4616:( 4585:0 4551:0 4526:) 4523:t 4520:( 4517:s 4491:0 4450:0 4425:, 4420:) 4417:t 4412:0 4401:) 4398:t 4395:( 4389:( 4386:j 4382:e 4378:) 4375:t 4372:( 4366:m 4361:s 4357:= 4352:t 4347:0 4339:j 4332:e 4328:) 4325:t 4322:( 4316:a 4311:s 4304:) 4301:t 4298:( 4285:a 4280:s 4236:. 4233:) 4230:t 4227:( 4215:2 4211:1 4203:) 4200:t 4197:( 4194:f 4158:. 4155:) 4152:t 4149:( 4143:t 4140:d 4132:d 4123:) 4120:t 4117:( 4076:) 4073:t 4070:( 4064:m 4059:s 4038:) 4035:t 4032:( 4029:s 4017:. 3994:] 3990:) 3987:t 3984:( 3978:a 3973:s 3968:[ 3957:) 3954:t 3951:( 3938:; 3915:| 3911:) 3908:t 3905:( 3899:a 3894:s 3889:| 3882:) 3879:t 3876:( 3870:m 3865:s 3838:, 3833:) 3830:t 3827:( 3821:j 3817:e 3813:) 3810:t 3807:( 3801:m 3796:s 3792:= 3789:) 3786:t 3783:( 3777:a 3772:s 3716:= 3711:t 3705:j 3698:e 3689:t 3683:j 3676:e 3672:= 3667:t 3661:j 3654:e 3648:2 3644:j 3640:+ 3635:t 3629:j 3622:e 3618:= 3611:) 3608:t 3605:( 3599:a 3594:s 3586:, 3581:t 3575:j 3568:e 3564:j 3561:= 3554:) 3551:t 3548:( 3539:s 3517:. 3505:0 3477:t 3471:j 3464:e 3460:= 3457:) 3454:t 3451:( 3448:s 3425:) 3422:t 3419:( 3416:s 3396:) 3393:t 3390:( 3387:s 3367:) 3364:t 3361:( 3355:a 3350:s 3295:, 3287:j 3280:e 3271:t 3267:| 3259:| 3255:j 3251:e 3244:= 3239:) 3233:+ 3230:t 3224:( 3221:j 3214:e 3206:, 3203:0 3184:, 3176:j 3172:e 3163:t 3159:| 3151:| 3147:j 3143:e 3136:= 3125:) 3119:+ 3116:t 3110:( 3107:j 3103:e 3096:{ 3091:= 3088:) 3085:t 3082:( 3076:a 3071:s 3043:) 3037:) 3031:+ 3028:t 3022:( 3019:j 3012:e 3008:+ 3003:) 2997:+ 2994:t 2988:( 2985:j 2981:e 2976:( 2970:2 2967:1 2962:= 2959:) 2953:+ 2950:t 2944:( 2935:= 2932:) 2929:t 2926:( 2923:s 2888:. 2884:) 2878:t 2875:) 2866:( 2863:j 2859:e 2855:+ 2850:t 2844:j 2840:e 2835:( 2829:2 2826:1 2821:= 2818:) 2815:t 2809:( 2768:. 2763:t 2757:j 2753:e 2749:= 2746:) 2743:t 2737:( 2728:j 2725:+ 2722:) 2719:t 2713:( 2704:= 2701:) 2698:t 2695:( 2686:s 2680:j 2677:+ 2674:) 2671:t 2668:( 2665:s 2662:= 2655:) 2652:t 2649:( 2643:a 2638:s 2630:, 2627:) 2624:t 2618:( 2609:= 2605:) 2599:2 2588:t 2581:( 2571:= 2564:) 2561:t 2558:( 2549:s 2490:, 2487:) 2484:t 2478:( 2469:= 2466:) 2463:t 2460:( 2457:s 2404:. 2401:) 2398:t 2395:( 2392:s 2372:] 2369:) 2366:t 2363:( 2352:a 2347:s 2343:[ 2334:= 2331:) 2328:t 2325:( 2322:s 2298:) 2295:t 2292:( 2281:a 2276:s 2255:] 2252:) 2249:t 2246:( 2240:a 2235:s 2231:[ 2205:] 2202:) 2199:t 2196:( 2190:a 2185:s 2181:[ 2172:= 2169:) 2166:t 2163:( 2160:s 2132:. 2127:} 2124:) 2121:f 2118:( 2115:u 2112:2 2109:{ 2104:1 2095:F 2082:] 2075:t 2068:1 2063:j 2060:+ 2057:) 2054:t 2051:( 2044:[ 2034:) 2031:t 2028:( 2025:s 2022:= 2019:) 2016:t 2013:( 2007:a 2002:s 1989:: 1975:, 1972:) 1969:t 1966:( 1957:) 1954:t 1951:( 1948:s 1945:= 1942:) 1939:t 1936:( 1933:s 1921:. 1905:j 1869:; 1857:) 1854:t 1851:( 1848:s 1824:] 1821:) 1818:t 1815:( 1812:s 1809:[ 1801:H 1793:) 1790:t 1787:( 1778:s 1745:, 1742:) 1739:t 1736:( 1727:s 1721:j 1718:+ 1715:) 1712:t 1709:( 1706:s 1703:= 1691:] 1688:) 1685:t 1682:( 1679:s 1676:[ 1668:H 1656:] 1652:) 1649:t 1646:( 1643:s 1634:t 1627:1 1621:[ 1614:j 1611:+ 1608:) 1605:t 1602:( 1599:s 1596:= 1572:) 1569:t 1566:( 1563:s 1553:} 1550:) 1547:f 1544:( 1541:S 1538:{ 1533:1 1524:F 1506:t 1499:1 1494:j 1484:} 1481:) 1478:f 1475:( 1466:{ 1461:1 1452:F 1438:+ 1433:) 1430:t 1427:( 1424:s 1414:} 1411:) 1408:f 1405:( 1402:S 1399:{ 1394:1 1385:F 1375:= 1365:] 1362:) 1359:f 1356:( 1353:S 1347:) 1344:f 1341:( 1332:+ 1329:) 1326:f 1323:( 1320:S 1317:[ 1312:1 1303:F 1297:= 1287:] 1284:) 1281:f 1278:( 1272:a 1267:S 1263:[ 1258:1 1249:F 1236:) 1233:t 1230:( 1224:a 1219:s 1191:) 1188:f 1185:( 1179:a 1174:S 1153:) 1150:t 1147:( 1144:s 1113:. 1110:] 1101:) 1097:f 1091:( 1085:a 1080:S 1076:+ 1073:) 1070:f 1067:( 1061:a 1056:S 1052:[ 1047:2 1044:1 1039:= 1014:0 1008:f 995:, 986:) 982:f 976:( 970:a 965:S 959:2 956:1 947:, 944:0 941:= 938:f 925:, 922:) 919:f 916:( 910:a 905:S 897:, 894:0 888:f 875:, 872:) 869:f 866:( 860:a 855:S 849:2 846:1 838:{ 833:= 826:) 823:f 820:( 817:S 790:) 787:f 784:( 781:S 761:) 758:f 755:( 752:S 736:, 720:) 717:f 714:( 698:, 682:) 679:f 676:( 670:u 640:, 637:) 634:f 631:( 628:S 625:) 622:f 619:( 610:+ 607:) 604:f 601:( 598:S 595:= 592:) 589:f 586:( 583:S 578:) 575:f 572:( 563:+ 560:1 550:) 547:f 544:( 538:u 535:2 528:= 511:0 505:f 492:, 489:0 482:, 479:0 476:= 473:f 460:, 457:) 454:f 451:( 448:S 441:, 438:0 432:f 419:, 416:) 413:f 410:( 407:S 404:2 398:{ 386:) 383:f 380:( 374:a 369:S 341:) 338:f 335:( 332:S 302:) 298:f 295:( 292:S 269:, 260:) 256:f 253:( 250:S 247:= 244:) 241:f 235:( 232:S 209:0 206:= 203:f 179:f 159:) 156:f 153:( 150:S 126:) 123:t 120:( 117:s 27:.

Index

analytic expression
analytic function
mathematics
signal processing
complex-valued function
negative frequency
Hilbert transform
real-valued
Fourier transform
spectrum
Hermitian symmetry
phasor

Hermitian
complex conjugate
Heaviside step function
sign function
Hilbert transform
convolution
imaginary unit
Euler's formula
corollary
negative frequency

polar coordinates
envelope
instantaneous phase
unwrapped
instantaneous frequency
hertz

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